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Mora García S, Gutierrez I, Nguyen JV, Navea JG, Grassian VH. Enhanced HONO Formation from Aqueous Nitrate Photochemistry in the Presence of Marine Relevant Organics: Impact of Marine-Dissolved Organic Matter (m-DOM) Concentration on HONO Yields and Potential Synergistic Effects of Compounds within m-DOM. ACS ES&T AIR 2024; 1:525-535. [PMID: 38898933 PMCID: PMC11184552 DOI: 10.1021/acsestair.4c00006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/18/2024] [Accepted: 04/18/2024] [Indexed: 06/21/2024]
Abstract
Nitrous acid (HONO) is a key molecule in the reactive nitrogen cycle. However, sources and sinks for HONO are not fully understood. Particulate nitrate photochemistry has been suggested to play a role in the formation of HONO in the marine boundary layer (MBL). Here we investigate the impact of marine relevant organic compounds on HONO formation from aqueous nitrate photochemistry. In particular, steady-state, gas-phase HONO yields were measured from irradiated nitrate solutions at low pH containing marine-dissolved organic matter (m-DOM). m-DOM induces a nonlinear increase in HONO yield across all concentrations compared to that for pure nitrate solutions, with rates of HONO formation increasing by up to 3-fold when m-DOM is present. Furthermore, to understand the potential synergistic effects that may occur within complex samples such as m-DOM, mixtures of chromophoric (light-absorbing) and aliphatic (non-light-absorbing) molecular proxies were utilized. In particular, mixtures of 4-benzoylbenzoic acid (4-BBA) and ethylene glycol (EG) in acidic aqueous solutions containing nitrate showed more HONO upon irradiation compared to solutions containing only one of the molecular proxies. This suggests that synergistic effects in the HONO formation can occur in complex organic samples. Atmospheric implications of the results presented here are discussed.
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Affiliation(s)
- Stephanie
L. Mora García
- Department
of Chemistry and Biochemistry, University
of California San Diego, La Jolla 92037, California, United States
| | - Israel Gutierrez
- Department
of Chemistry and Biochemistry, University
of California San Diego, La Jolla 92037, California, United States
| | - Jillian V. Nguyen
- Department
of Chemistry and Biochemistry, University
of California San Diego, La Jolla 92037, California, United States
| | - Juan G. Navea
- Department
of Chemistry, Skidmore College, Saratoga Springs 12866, New York, United States
| | - Vicki H. Grassian
- Department
of Chemistry and Biochemistry, University
of California San Diego, La Jolla 92037, California, United States
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2
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Du R, Wen J, Huang J, Zhang Q, Shi X, Wang B, Deng S, Yu G. Dissolved organic matter isolates obtained by solid phase extraction exhibit higher absorption and lower photo-reactivity: Effect of components. WATER RESEARCH 2024; 256:121604. [PMID: 38640562 DOI: 10.1016/j.watres.2024.121604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 03/24/2024] [Accepted: 04/10/2024] [Indexed: 04/21/2024]
Abstract
Notable differences in photo-physical and chemical properties were found between bulk water and solid phase extraction (SPE) isolates for dissolved organic matter (DOM). The moieties extracted using modified styrene divinylbenzene cartridges, which predominantly consist of conjugated aromatic molecules like humic acids, contribute mainly to light absorption but exhibit lower quantum yields of fluorescence and photo-produced reactive intermediates (PPRIs). Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) revealed lignin as the moieties displaying most significant variance in abundance. In Van Krevelen-Spearman plot, we observed molecules positively or negatively correlated with DOM's optical and photochemical properties (including SUVA254, steady-state concentrations of ·OH, 1O2 quantum yield, etc.) were confined to specific regions, which can be delineated using a threshold modified aromaticity index (AImod) of 0.3. Based on the relationships between optical properties and PPRI production, it is suggested that the energy gap between ground state and excited singlet state (△ES1→S0), governing the inner conversion rate, serves as a determinant for apparent quantum yield of PPRIs in DOM, with intra-molecular charge transfer (CT) interactions potentially playing a pivotal role. Regarding DOM's photoreactivity with pollutants, this study has revealed, for the first time, that protein/amino sugars/amino acids could act as antioxidant groups in addition to phenols on the photolysis of sulfadiazine. These findings provide valuable insights into DOM photochemistry and are expected to stimulate further research in this area.
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Affiliation(s)
- Roujia Du
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Jiaqi Wen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Jun Huang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Qianxin Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Xiaoyu Shi
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Bin Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Shubo Deng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Gang Yu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China; Advanced Interdisciplinary Institute of Environmental and Ecology, Beijing Normal University, Zhuhai, 519087, China.
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3
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Zhao Y, Xu X, Huang T, Ahmed HG, Jha K, Wu B. Efficient photochemical conversion of naproxen by butanedione: Role of energy transfer. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134258. [PMID: 38608588 DOI: 10.1016/j.jhazmat.2024.134258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 02/17/2024] [Accepted: 04/08/2024] [Indexed: 04/14/2024]
Abstract
Photochemical active species generated from photosensitizers, e.g., dissolved organic matter (DOM), play vital roles in the transformation of micropollutants in water. Here, butanedione (BD), a redox-active moiety in DOM and widely found in nature, was employed to photo-transform naproxen (NPX) with peracetic acid (PAA) and H2O2 as contrasts. The results obtained showed that the BD exhibited more applicable on NPX degradation. It works in the lake or river water under UV and solar irradiation, and its NPX degradation efficiency was 10-30 times faster than that of PAA and H2O2. The reason for the efficient transformation of pollutants is that the BD system was proved to be a non-free radical dominated mechanism. The quantum yield of BD (Ф254 nm) was calculated to be 0.064, which indicates that photophysical process is the dominant mode of BD conversion. By adding trapping agents, direct energy transfer from 3BD* to NPX (in anoxic environment) or dissolved oxygen (in aerobic environment) was proved to play a major role (> 91 %). Additionally, the BD process reduces the toxicity of NPX and promotes microbial growth after irradiation. Overall, this study significantly deepened the understanding of the transformation between BD and micropollutants, and provided a potential BD-based process for micropollutants removal under solar irradiation.
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Affiliation(s)
- Yue Zhao
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, People's Republic of China
| | - Xiaoyi Xu
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, People's Republic of China; Key Laboratory of Suzhou Sponge City Technology, Suzhou 215009, People's Republic of China
| | - Tianyin Huang
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, People's Republic of China; Key Laboratory of Suzhou Sponge City Technology, Suzhou 215009, People's Republic of China
| | - Hewr Gailani Ahmed
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, People's Republic of China
| | - Kartikesh Jha
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, People's Republic of China
| | - Bingdang Wu
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, People's Republic of China; Key Laboratory of Suzhou Sponge City Technology, Suzhou 215009, People's Republic of China.
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4
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Wang W, Liu Y, Wang T, Ge Q, Li K, Liu J, You W, Wang L, Xie L, Fu H, Chen J, Zhang L. Significantly Accelerated Photosensitized Formation of Atmospheric Sulfate at the Air-Water Interface of Microdroplets. J Am Chem Soc 2024; 146:6580-6590. [PMID: 38427385 DOI: 10.1021/jacs.3c11892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
The multiphase oxidation of sulfur dioxide (SO2) to form sulfate is a complex and important process in the atmosphere. While the conventional photosensitized reaction mainly explored in the bulk medium is reported to be one of the drivers to trigger atmospheric sulfate production, how this scheme functionalizes at the air-water interface (AWI) of aerosol remains an open question. Herein, employing an advanced size-controllable microdroplet-printing device, surface-enhanced Raman scattering (SERS) analysis, nanosecond transient adsorption spectrometer, and molecular level theoretical calculations, we revealed the previously overlooked interfacial role in photosensitized oxidation of SO2 in humic-like substance (HULIS) aerosol, where a 3-4 orders of magnitude increase in sulfate formation rate was speculated in cloud and aerosol relevant-sized particles relative to the conventional bulk-phase medium. The rapid formation of a battery of reactive oxygen species (ROS) comes from the accelerated electron transfer process at the AWI, where the excited triplet state of HULIS (3HULIS*) of the incomplete solvent cage can readily capture electrons from HSO3- in a way that is more efficient than that in the bulk medium fully blocked by water molecules. This phenomenon could be explained by the significantly reduced desolvation energy barrier required for reagents residing in the AWI region with an open solvent shell.
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Affiliation(s)
- Wei Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
| | - Yangyang Liu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
| | - Tao Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
| | - Qiuyue Ge
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
| | - Kejian Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
| | - Juan Liu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
| | - Wenbo You
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
| | - Longqian Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
| | - Lifang Xie
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
| | - Hongbo Fu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
| | - Jianmin Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
| | - Liwu Zhang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, Peoples' Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, Peoples' Republic of China
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5
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Yu W, Zheng X, Tan M, Wang J, Wu B, Ma J, Pan Y, Chen B, Chu C. Field Quantification of Hydroxyl Radicals by Flow-Injection Chemiluminescence Analysis with a Portable Device. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:2808-2816. [PMID: 38227742 DOI: 10.1021/acs.est.3c09140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Hydroxyl radical (•OH) is a powerful oxidant abundantly found in nature and plays a central role in numerous environmental processes. On-site detection of •OH is highly desirable for real-time assessments of •OH-centered processes and yet is restrained by a lack of an analysis system suitable for field applications. Here, we report the development of a flow-injection chemiluminescence analysis (FIA-CL) system for the continuous field detection of •OH. The system is based on the reaction of •OH with phthalhydrazide to generate 5-hydroxy-2,3-dihydro-1,4-phthalazinedione, which emits chemiluminescence (CL) when oxidatively activated by H2O2 and Cu3+. The FIA-CL system was successfully validated using the Fenton reaction as a standard •OH source. Unlike traditional absorbance- or fluorescence-based methods, CL detection could minimize interference from an environmental medium (e.g., organic matter), therefore attaining highly sensitive •OH detection (limits of detection and quantification = 0.035 and 0.12 nM, respectively). The broad applications of FIA-CL were illustrated for on-site 24 h detection of •OH produced from photochemical processes in lake water and air, where the temporal variations on •OH productions (1.0-12.2 nM in water and 1.5-37.1 × 107 cm-3 in air) agreed well with sunlight photon flux. Further, the FIA-CL system enabled field 24 h field analysis of •OH productions from the oxidation of reduced substances triggered by tidal fluctuations in coastal soils. The superior analytical capability of the FIA-CL system opens new opportunities for monitoring •OH dynamics under field conditions.
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Affiliation(s)
- Wanchao Yu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Xiaoshan Zheng
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Mengxi Tan
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Jingyi Wang
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Binbin Wu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Junye Ma
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Yishuai Pan
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Baoliang Chen
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Chiheng Chu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
- ZJU-Anqing Yangtze Delta Future Industry Institute, Anqing 246003, China
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6
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Wan D, Song G, Mi W, Tu X, Zhao Y, Bi Y. Insights into the Enhanced Photogeneration of Hydroxyl Radicals from Chlorinated Dissolved Organic Matter. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:805-815. [PMID: 38156625 DOI: 10.1021/acs.est.3c08257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Free available chlorine has been and is being applied in global water treatment and readily reacts with dissolved organic matter (DOM) in aquatic environments, leading to the formation of chlorinated products. Chlorination enhances the photoreactivity of DOM, but the influence of chlorinated compounds on the photogeneration of hydroxyl radicals (•OH) has remained unexplored. In this study, a range of chlorinated carboxylate-substituted phenolic model compounds were employed to assess their •OH photogeneration capabilities. These compounds demonstrated a substantial capacity for •OH production, exhibiting quantum yields of 0.1-5.9 × 10-3 through direct photolysis under 305 nm and 0.2-9.5 × 10-3 through a triplet sensitizer (4-benzoylbenzoic acid)-inducing reaction under 365 nm LED irradiation. Moreover, the chlorinated compounds exhibited higher light absorption and •OH quantum yields compared to those of their unchlorinated counterparts. The •OH photogeneration capacity of these compounds exhibited a positive correlation with their triplet state one-electron oxidation potentials. Molecular-level compositional analysis revealed that aromatic structures rich in hydroxyl and carboxyl groups (e.g., O/C > 0.5 with H/C < 1.5) within DOM serve as crucial sources of •OH, and chlorination of these compounds significantly enhances their capacity to generate •OH upon irradiation. This study provides novel insights into the enhanced photogeneration of •OH from chlorinated DOM, which is helpful for understanding the fate of trace pollutants in chlorinated waters.
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Affiliation(s)
- Dong Wan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
| | - Gaofei Song
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
| | - Wujuan Mi
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
| | - Xiaojie Tu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
| | - Yafei Zhao
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
| | - Yonghong Bi
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
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7
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Oden CP, Werth CJ, Kienzle BA, Katz LE. Impact of organic matter on transformation during thermal remediation of pyrene-contaminated substrates. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167569. [PMID: 37793444 DOI: 10.1016/j.scitotenv.2023.167569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/29/2023] [Accepted: 10/01/2023] [Indexed: 10/06/2023]
Abstract
Thermal remediation (TR) is a broadly applicable technology that is effective at removing volatile and semi-volatile contaminants from soil. However, TR can be costly and inefficient in practice, with underlying removal and transformation mechanisms poorly understood. To better understand the role organic matter plays in removal, a series of experiments was performed with a humic substance, humic modified silica, and a natural soil in the presence of pyrene from 100 to 500 °C and compared to prior experiments using pure minerals. Detection of by-products confirmed that pyrene was removed by transformation in addition to volatilization. Oxidation via hydroxyl radical formation and reductive hydrogenation were both indicated as possible reaction mechanisms promoted by organic matter. Because the presence of bulk water did not impact the extent of pyrene degradation or transformation, it is hypothesized that hydroxyl radicals were produced from soil organic matter functional groups, such as carboxyl and phenol groups, and possibly bound water at elevated temperatures in dry experiments. Additionally, the average oxidation state of carbon in detected by-products increased with temperature in experiments with humic modified silica and soil but not humic substance alone, though the extent of degradation did not significantly change. This shift in oxidation state may indicate that attachment of organic matter to another surface may increase interaction between reactive species. The results of this study show that contaminant transformation in soils during TR significantly contributes to removal, even at temperatures lower than those used in traditional treatment. This information will help to guide the design and operation of TR systems, potentially reducing energy requirements and highlighting the necessity of testing for transformation by-products.
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Affiliation(s)
- Cameron P Oden
- Department of Civil, Architectural, and Environmental Engineering, University of Texas at Austin, 301 E Dean Keeton St, Austin, TX, USA.
| | - Charles J Werth
- Department of Civil, Architectural, and Environmental Engineering, University of Texas at Austin, 301 E Dean Keeton St, Austin, TX, USA.
| | - Benjamin A Kienzle
- Department of Civil, Architectural, and Environmental Engineering, University of Texas at Austin, 301 E Dean Keeton St, Austin, TX, USA.
| | - Lynn E Katz
- Department of Civil, Architectural, and Environmental Engineering, University of Texas at Austin, 301 E Dean Keeton St, Austin, TX, USA.
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8
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Chen R, Xiao T, Dai X, Dong B. Roles of extracellular polymeric substances in the adsorption and removal of norfloxacin during hydrothermal treatment of sewage sludge. WATER RESEARCH 2024; 248:120899. [PMID: 38000225 DOI: 10.1016/j.watres.2023.120899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 11/17/2023] [Accepted: 11/18/2023] [Indexed: 11/26/2023]
Abstract
Hydrothermal treatment (HT) is promising to remove antimicrobials from sewage sludge (SS); however, the mechanism of antimicrobial degradation during the HT of SS is not fully understood. In this study, the roles of extracellular polymeric substances (EPS) in the removal and transformation of norfloxacin (NOR) during the HT of SS at temperatures of 100 and 160 °C were investigated. The results indicated that the degradation of NOR increased with increasing HT temperature, with maximum NOR removal (52%) achieved at 160 °C. Furthermore, the NOR in sludge showed higher degradation efficiencies than the control as HT temperature was higher than 120 °C. Evident promotion effects of bound-EPS (B-EPS) in sludge were observed on the NOR degradation as HT temperature was higher than 120 °C, leading to the mineralization and deamination of protein-like components in EPS during HT. Beside, the adsorption capacity of NOR during the HT of SS decreased at temperatures higher than 120 °C. The evolution of the spatial structure of B-EPS was predominantly responsible for the adsorption of antimicrobials, a spontaneous process driven mainly by hydrophilic interactions. With the hydrothermal conversion of B-EPS, the electron transfer, and reactive species (3EPS* and ·OH) derived from B-EPS could facilitate the degradation of NOR. In particular, hydrogen bonds between B-EPS and NOR increased the apparent yield of ·OH and accelerated the decarboxylation of NOR during HT at temperatures higher than 120 °C. A toxicity evaluation suggested that HT for NOR degradation could attenuate toxicity, whereas deep oxidation or mineralization would be needed to promote ecosystem safety. These findings provide new insights into the hydrothermal activation of EPS and the interrelated hydrothermal fate of antimicrobials and other toxic pollutants in sludge.
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Affiliation(s)
- Renjie Chen
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Tingting Xiao
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Xiaohu Dai
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Bin Dong
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China; YANGTZE Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing 100038, PR China.
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9
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Redman ZC, Begley JL, Hillestad I, DiMento BP, Stanton RS, Aguaa AR, Pirrung MC, Tomco PL. Reactive Oxygen Species and Chromophoric Dissolved Organic Matter Drive the Aquatic Photochemical Pathways and Photoproducts of 6PPD-quinone under Simulated High-Latitude Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:20813-20821. [PMID: 38032317 DOI: 10.1021/acs.est.3c05742] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
The photochemical degradation pathways of 6PPD-quinone (6PPDQ, 6PPD-Q), a toxic transformation product of the tire antiozonant 6PPD, were determined under simulated sunlight conditions typical of high-latitude surface waters. Direct photochemical degradation resulted in 6PPDQ half-lives ranging from 17.5 h at 20 °C to no observable degradation over 48 h at 4 °C. Sensitization of excited triplet-state pathways using Cs+ and Ar purging demonstrated that 6PPDQ does not decompose significantly from a triplet state relative to a singlet state. However, assessment of processes involving reactive oxygen species (ROS) quenchers and sensitizers indicated that singlet oxygen and hydroxyl radical do significantly contribute to the degradation of 6PPDQ. Investigation of these processes in natural lake waters indicated no difference in attenuation rates for direct photochemical processes at 20 °C. This suggests that direct photochemical degradation will dominate in warm waters, while indirect photochemical pathways will dominate in cold waters, involving ROS mediated by chromophoric dissolved organic matter (CDOM). Overall, the aquatic photodegradation rate of 6PPDQ will be strongly influenced by the compounding effects of environmental factors such as light screening and temperature on both direct and indirect photochemical processes. Transformation products were identified via UHPLC-Orbitrap mass spectrometry, revealing four major processes: (1) oxidation and cleavage of the quinone ring in the presence of ROS, (2) dealkylation, (3) rearrangement, and (4) deamination. These data indicate that 6PPDQ can photodegrade in cool, sunlit waters under the appropriate conditions: t1/2 = 17.4 h tono observable decrease (direct); t1/2 = 5.2-11.2 h (indirect, CDOM).
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Affiliation(s)
- Zachary C Redman
- Department of Chemistry, College of Arts and Sciences, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, Alaska 99508, United States
| | - Jessica L Begley
- Department of Chemistry, College of Arts and Sciences, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, Alaska 99508, United States
| | - Isabel Hillestad
- Department of Chemistry, College of Arts and Sciences, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, Alaska 99508, United States
| | - Brian P DiMento
- Department of Chemistry, College of Arts and Sciences, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, Alaska 99508, United States
| | - Ryan S Stanton
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Alon R Aguaa
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Michael C Pirrung
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Patrick L Tomco
- Department of Chemistry, College of Arts and Sciences, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, Alaska 99508, United States
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10
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Sanei E, Marquez I. DOM optical parameters as a tool to understand degradation of phenolic contaminants of emerging concern. CHEMOSPHERE 2023; 340:139750. [PMID: 37574083 DOI: 10.1016/j.chemosphere.2023.139750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/04/2023] [Accepted: 08/05/2023] [Indexed: 08/15/2023]
Abstract
Composition and source of dissolved organic matter (DOM) in water influence the rate of production of reactive intermediates (RIs), affecting the photodegradation of phenolic contaminants of emerging concern (PhCECs). However, this relationship has not been fully quantified. Here, for the first time, we propose a mechanism for photodegradation of a surrogate of PhCECs, p-cresol, in different DOM standard solutions under simulated sunlight irradiation. More importantly, the correlation of DOM optical parameters and p-cresol photodegradation kinetic parameters was determined by Pearson correlation. Results showed that indirect photodegradation was the only degradation pathway for p-cresol, mainly through reaction with excited triplet state of dissolved organic matter (3DOM*). Singlet oxygen (1O2) and hydroxyl radical (•OH) hindered degradation of p-cresol by decreasing the steady state concentration of 3DOM*. Moreover, less aromatic and smaller molecular size DOM showed higher steady-state concentration and quantum yield of 1O2, and 3DOM*, resulting in faster p-cresol photodegradation. Finally, 7 out of 8 optical parameters showed strong correlation with the p-cresol photodegradation rate constant. The mechanism and correlations found are a potential tool to predict PhCECs photodegradation in water using DOM optical parameters.
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Affiliation(s)
- Emad Sanei
- School of Engineering and Technology, Central Michigan University, 1200 S Franklin St, Mt Pleasant, MI, 48859, USA
| | - Itzel Marquez
- School of Engineering and Technology, Central Michigan University, 1200 S Franklin St, Mt Pleasant, MI, 48859, USA.
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11
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Milstead RP, Berg SM, Kelly BM, Knellwolf CD, Larson CJ, Wammer KH, Remucal CK. Limitations of conventional approaches to identify photochemically produced reactive intermediates involved in contaminant indirect photodegradation. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:1694-1707. [PMID: 37728410 PMCID: PMC10591881 DOI: 10.1039/d3em00304c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Dissolved organic matter (DOM) mediated indirect photodegradation can play an important role in the degradation of aquatic contaminants. Predicting the rate of this process requires knowledge of the photochemically produced reactive intermediates (PPRI) that react with the compound of interest, as well as the ability of individual DOM samples to produce PPRI. Key PPRI are typically identified using quencher studies, yet this approach often leads to results that are difficult to interpret. In this work, we analyze the indirect photodegradation of atorvastatin, carbamazepine, sulfadiazine, and benzotriazole using a diverse set of 48 waters from natural and engineered aquatic systems. We use this large data set to evaluate relationships between PPRI formation and indirect photodegradation rate constants, which are directly compared to results using standard quenching experiments. These data demonstrate that triplet state DOM (3DOM) and singlet oxygen (1O2) are critical PPRI for atorvastatin, carbamazepine, and sulfadiazine, while hydroxyl radical (˙OH) contributes to the indirect photodegradation of benzotriazole. We caution against relying on quenching studies because quenching of 3DOM limits the formation of 1O2 and all studied quenchers react with ˙OH. Furthermore, we show that DOM composition directly influences indirect photodegradation and that low molecular weight, microbial-like DOM is positively correlated with the indirect photodegradation rates of carbamazepine, sulfadiazine, and benzotriazole.
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Affiliation(s)
- Reid P Milstead
- Environmental Chemistry and Technology Program, University of Wisconsin-Madison, 660 N. Park St., Madison, Wisconsin 53706, USA.
| | - Stephanie M Berg
- Environmental Chemistry and Technology Program, University of Wisconsin-Madison, 660 N. Park St., Madison, Wisconsin 53706, USA.
| | - Bella M Kelly
- Department of Chemistry, University of St. Thomas, St. Paul, Minnesota 55105, USA
| | | | - Cooper J Larson
- Department of Chemistry, University of St. Thomas, St. Paul, Minnesota 55105, USA
| | - Kristine H Wammer
- Department of Chemistry, University of St. Thomas, St. Paul, Minnesota 55105, USA
| | - Christina K Remucal
- Environmental Chemistry and Technology Program, University of Wisconsin-Madison, 660 N. Park St., Madison, Wisconsin 53706, USA.
- Department of Civil and Environmental Engineering, University of Wisconsin - Madison, Madison, Wisconsin 53706, USA
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12
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Cai T, Zhang X, Zhang S, Ming Y, Zhang Q. Photochemical behaviors of dissolved organic matter in aquatic environment: Generation, characterization, influencing factors and practical application. ENVIRONMENTAL RESEARCH 2023; 231:116174. [PMID: 37209983 DOI: 10.1016/j.envres.2023.116174] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 04/05/2023] [Accepted: 05/15/2023] [Indexed: 05/22/2023]
Abstract
Dissolved organic matter (DOM) widely exists in aquatic environment and plays a critical role in environmental photochemical reaction. The photochemical behaviors of DOM in sunlit surface waters have received widely attention because its photochemical effects for some coexisted substances in aquatic environment, especially for organic micropollutants degradation. Therefore, to gain a comprehensive understanding of the photochemical properties and environmental effects of DOM, we reviewed the influence of sources on the structure and composition of DOM with relevant identified techniques to analysis functional groups. Additionally, identification and quantification for reactive intermediates are discussed with a focus on influencing factors to produce reactive intermediates by DOM under solar irradiation. These reactive intermediates can promote the photodegradation of organic micropollutants in the environmental system. In future, attention should be paid to the photochemical properties of DOM and environmental effects in real environmental system and development of advanced techniques to study DOM.
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Affiliation(s)
- Tong Cai
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, 200241, Shanghai, China
| | - Xiaotong Zhang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, 200241, Shanghai, China
| | - Shudong Zhang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, 200241, Shanghai, China
| | - Yuanbo Ming
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, 200241, Shanghai, China
| | - Qiuzhuo Zhang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, 200241, Shanghai, China; Institute of Eco-Chongming (IEC), 3663 N. Zhongshan Rd., Shanghai, 200062, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N. Zhongshan Road, Shanghai, 200062, China.
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13
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Zeng G, Shi M, Dai M, Zhou Q, Luo H, Lin L, Zang K, Meng Z, Pan X. Hydroxyl radicals in natural waters: Light/dark mechanisms, changes and scavenging effects. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 868:161533. [PMID: 36640880 DOI: 10.1016/j.scitotenv.2023.161533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 06/17/2023]
Abstract
Hydroxyl radicals (•OH) are the most active, aggressive and oxidative reactive oxygen species. In the natural aquatic environment, •OH plays an important role in the biogeochemistry cycle, biotransformation, and pollution removal. This paper reviewed the distribution and formation mechanism of •OH in aquatic environments, including natural waters, colloidal substances, sediments, and organisms. Furthermore, factors affecting the formation and consumption of •OH were thoroughly discussed, and the mechanisms of •OH generation and scavenging were summarized. In particular, the effects of climate change and artificial work on •OH in the largest natural aquatic environment, i.e., marine environment was analyzed with the help of bibliometrics. Moreover, Fenton reactions make the •OH variation more complicated and should not be neglected, especially in those areas with suspended particles and sediments. Regarding the •OH variation in the natural aquatic environment, more attention should be given to global change and human activities.
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Affiliation(s)
- Ganning Zeng
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China; Key Laboratory of Ocean Space Resource Management Technology, MNR, Hangzhou 310012, China
| | - Ming Shi
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Mengzheng Dai
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Qian Zhou
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Hongwei Luo
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Liangyu Lin
- Key Laboratory of Ocean Space Resource Management Technology, MNR, Hangzhou 310012, China; Zhejiang Academy of Marine Science, Hangzhou 310012, China
| | - Kunpeng Zang
- Zhejiang Carbon Neutral Innovation Institute, Zhejiang University of Technology, Hangzhou 310014, China
| | - Zhu Meng
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Xiangliang Pan
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
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14
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Tang G, Li B, Zhang B, Hu S, Chen S, Liu T, Wang Q, Qiao H, Zheng X. Temperature effects on microbial dissolved organic matter metabolisms: Linking size fractions, fluorescent compositions, and functional groups. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 864:161175. [PMID: 36572301 DOI: 10.1016/j.scitotenv.2022.161175] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 12/19/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
This study elucidated the compositional and structural variations of size fractions of microbially-induced dissolved organic matter (DOM) caused by short-term temperature changes (5 to 35 °C), taking riverine DOM as an example. A simple and efficient method combining fractionation-[parallel factor analysis and two-dimensional Fourier-transform infrared correlation spectroscopy (PARAFAC-2D FTIR COS)]-correlation was introduced to link fluorescent DOM components and their structures in terms of surface functional groups. Results indicated that the higher temperature stimulated the decomposition of aromatics (sizes decreased from 10 kDa-0.22 μm to <10 kDa) and the transformation of proteins to humics (with sizes <0.22 μm); while both the higher and lower temperatures inhibited the utilization of larger-sized DOM (>0.22 μm, especially the non-fluorescence part) and synthesis of larger-sized microbial-derived proteins and humics (>0.22 μm), which may result in more smaller-sized (<10 kDa) and refractory aromatics transported from rivers to oceans in the warming future. However, the structure-determined DOM behaviors could be less affected by temperature since the fluorescent proteins and humics revealed similar functional group compositions, such as carboxyl, hydroxyl, carbonyl/aldehyde, carboxylic anhydride, and carboxamide groups. These findings have strong implications for DOM biogeochemistry in future temperature-shock scenarios. The proposed method will support in-depth analyses of structure-regulated processes from a mechanistic perspective.
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Affiliation(s)
- Gang Tang
- State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi'an University of Technology, Xi'an 710048, China; Melbourne Climate Futures Academy, Climate & Energy College, School of Geography, Earth and Atmospheric Sciences, The University of Melbourne, Melbourne, VIC 3010, Australia; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Binrui Li
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Civil and Environmental Engineering Department, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
| | - Bowei Zhang
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Shiwen Hu
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Shuling Chen
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Tong Liu
- State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi'an University of Technology, Xi'an 710048, China
| | - Qianqian Wang
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Han Qiao
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xing Zheng
- State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi'an University of Technology, Xi'an 710048, China.
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15
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Fan T, Yao X, Sun Z, Sang D, Liu L, Deng H, Zhang Y. Properties and metal binding behaviors of sediment dissolved organic matter (SDOM) in lakes with different trophic states along the Yangtze River Basin: A comparison and summary. WATER RESEARCH 2023; 231:119605. [PMID: 36680825 DOI: 10.1016/j.watres.2023.119605] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 06/17/2023]
Abstract
The nature of sediment dissolved organic matter (SDOM) can reflect the environmental background, nutritional status and human activities and is an important part of lakes. The differences in the binding capacity of heavy metals and organic matter in lake sediments with different trophic states at the catchment scale and the mechanism of the differences in binding are still unclear. To solve this problem, we collected bulk SDOMs (< 0.7 μm) from 6 respective lakes (from upstream to downstream) in the Yangtze River Basin (YRB) to qualitatively and quantitatively characterize their properties and metal binding behaviors using excitation-emission matrix spectroscopy combined with parallel factor analysis (EEM-FARAFAC) and two-dimensional correlation spectroscopy of synchronous fluorescence spectroscopy and Fourier transform infrared spectroscopy (2D-SF-COS and 2D-FTIR-COS). The results showed that sediment dissolved organic carbon (SDOC) was mainly enriched in low molecular weight (LMW: < 1 kDa) fractions. The total fluorescence intensity (Fmax) of SDOM from upstream was larger than that from downstream (p = 0.033), and humic-like fluorophores were dominant in these lakes. The Fmax of sediment humic-like components (C1+C2) was closely related to the trophic levels of the lakes. Protein-like substances and oxygen-containing functional groups (C-OH, C=O, and C-O) were preferred in the reaction between SDOM and copper (Cu2+) or cadmium (Cd2+), while a unique binding path was exhibited in the moderately eutrophic DCL. In terms of fluorophore types, higher Cu2+-binding abilities (LogKCu) were observed in the humic-like matter for the lakes in the upper reaches and tryptophan-like matter for the lakes from the midstream and downstream areas of the YRB. Although Cd2+ complexed only with humic-like matter, LogKCd was higher than LogKCu. In terms of molecular weight (MW), the LogKCu/Cd of components were enhanced after MW fractionation. The HMW (0.7 μm - 1 kDa) components possessed higher LogKCu in most lakes (except for CHL and C4). The different fluorophores and molecular weight fractions in SDOM make an important contribution to reducing the ecological risks of heavy metals in lakes.
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Affiliation(s)
- Tuantuan Fan
- School of Geography and Environment, University of Liaocheng, Liaocheng 252000, China; Institute of Huanghe Studies, University of Liaocheng, Liaocheng 252000, China
| | - Xin Yao
- School of Geography and Environment, University of Liaocheng, Liaocheng 252000, China; Institute of Huanghe Studies, University of Liaocheng, Liaocheng 252000, China.
| | - Zhaoli Sun
- School of Geography and Environment, University of Liaocheng, Liaocheng 252000, China
| | - Dongling Sang
- School of Geography and Environment, University of Liaocheng, Liaocheng 252000, China
| | - Li Liu
- School of Geography and Environment, University of Liaocheng, Liaocheng 252000, China
| | - Huanguang Deng
- School of Geography and Environment, University of Liaocheng, Liaocheng 252000, China
| | - Yinghao Zhang
- School of Geography and Environment, University of Liaocheng, Liaocheng 252000, China
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16
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Guo Z, Kodikara D, Albi LS, Hatano Y, Chen G, Yoshimura C, Wang J. Photodegradation of organic micropollutants in aquatic environment: Importance, factors and processes. WATER RESEARCH 2023; 231:118236. [PMID: 36682233 DOI: 10.1016/j.watres.2022.118236] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/22/2022] [Accepted: 02/23/2022] [Indexed: 06/17/2023]
Abstract
Photochemical reactions widely occur in the aquatic environment and play fundamental roles in aquatic ecosystems. In particular, solar-induced photodegradation is efficient for many organic micropollutants (OMPs), especially those that cannot undergo hydrolysis or biodegradation, and thus can mitigate chemical pollution. Recent reports indicate that photodegradation may play a more important role than biodegradation in many OMP transformations in the aquatic environment. Photodegradation can be influenced by the water matrix such as pH, inorganic ions, and dissolved organic matter (DOM). The effect of the water matrix such as DOM on photodegradation is complex, and new insights concerning the disparate effects of DOM have recently been reported. In addition, the photodegradation process is also influenced by physical factors such as latitude, water depth, and temporal variations in sunlight as these factors determine the light conditions. However, it remains challenging to gain an overview of the importance of photodegradation in the aquatic environment because the reactions involved are diverse and complex. Therefore, this review provides a concise summary of the importance of photodegradation and the major processes related to the photodegradation of OMPs, with particular attention given to recent progress on the major reactions of DOM. In addition, major knowledge gaps in this field of environmental photochemistry are highlighted.
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Affiliation(s)
- Zhongyu Guo
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8552, Japan
| | - Dilini Kodikara
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8552, Japan
| | - Luthfia Shofi Albi
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8552, Japan
| | - Yuta Hatano
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8552, Japan
| | - Guo Chen
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8552, Japan
| | - Chihiro Yoshimura
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8552, Japan.
| | - Jieqiong Wang
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
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17
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Zheng X, Wu B, Zhou C, Liu T, Wang Y, Zhao G, Chen B, Chu C. Sunlight-Driven Production of Reactive Oxygen Species from Natural Iron Minerals: Quantum Yield and Wavelength Dependence. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:1177-1185. [PMID: 36538289 DOI: 10.1021/acs.est.2c06942] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Photochemically generated reactive oxygen species (ROS) play numerous key roles in earth's surface biogeochemical processes and pollutant dynamics. ROS production has historically been linked to the photosensitization of natural organic matter. Here, we report the photochemical ROS production from three naturally abundant iron minerals. All investigated iron minerals are photoactive toward sunlight irradiation, with photogenerated currents linearly correlated with incident light intensity. Hydroxyl radicals (•OH) and hydrogen peroxide (H2O2) are identified as the major ROS species, with apparent quantum yields ranging from 1.4 × 10-8 to 3.9 × 10-8 and 5.8 × 10-8 to 2.5 × 10-6, respectively. Photochemical ROS production exhibits high wavelength dependence, for instance, the •OH quantum yield decreases with the increase of light wavelength from 375 to 425 nm, and above 425 nm it sharply decreases to zero. The temperature shows a positive impact on •OH production, with apparent activation energies ranging from 8.0 to 17.8 kJ/mol. Interestingly, natural iron minerals with impurities exhibit higher ROS production than their pure crystal counterparts. Compared with organic photosensitizers, iron minerals exhibit higher wavelength dependence, higher selectivity, lower efficiency, and long-term stability in photochemical ROS production. Our study highlights natural inorganic iron mineral photochemistry as a ubiquitous yet previously overlooked source of ROS.
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Affiliation(s)
- Xiaoshan Zheng
- Department of Environmental Science, Zhejiang University, Hangzhou310058, China
| | - Binbin Wu
- Department of Environmental Science, Zhejiang University, Hangzhou310058, China
| | - Chong Zhou
- Department of Environmental Science, Zhejiang University, Hangzhou310058, China
| | - Tian Liu
- Department of Environmental Science, Zhejiang University, Hangzhou310058, China
| | - Yanling Wang
- Department of Environmental Science, Zhejiang University, Hangzhou310058, China
| | - Guoqiang Zhao
- Department of Environmental Science, Zhejiang University, Hangzhou310058, China
| | - Baoliang Chen
- Department of Environmental Science, Zhejiang University, Hangzhou310058, China
| | - Chiheng Chu
- Department of Environmental Science, Zhejiang University, Hangzhou310058, China
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18
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Cao R, Liu X, Duan J, Gao B, He X, Li Y. Opposite impact of DOM on ROS generation and photoaging of aromatic and aliphatic nano- and micro-plastic particles. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 315:120304. [PMID: 36181927 DOI: 10.1016/j.envpol.2022.120304] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 08/30/2022] [Accepted: 09/25/2022] [Indexed: 06/16/2023]
Abstract
Dissolved organic matter (DOM) plays a significant role in the photochemical behavior of nano- and micro-plastic particles (NPs/MPs). We investigated the influence of DOM on the mechanism on the photoaging of NPs/MPs with different molecular structures under UV365 irradiation in water. DOM components used in this study are mainly humic acid and fulvic acid. The results showed that DOM promoted the weathering of aliphatic NPs/MPs (polypropylene (PP)), but inhibited or had only a minor effect on the photoaging of aromatic NPs/MPs (polystyrene (PS) NPs/MPs, carboxyl-modified PS NPs, amino-modified PS NPs, and polycarbonate MPs). NPs with a large surface area may adsorb sufficient DOM on the particle surfaces through π-π interactions, which competes with NPs for photon absorption sites, thus, can delay the photoaging of PS NPs. Aromatic MPs may release phenolic compounds that quench •OH, thereby weakening the photoaging process. For aliphatic MPs, the detection of peracid, aldehyde, and ketone groups on the polymer surface indicated that DOM promoted weathering of PP MPs, which was primarily because the generation of •OH due to DOM photolysis may attack the polymer by C-C bond cleavage and hydrogen extraction reactions. This study provides insight into the UV irradiation weathering process of NPs/MPs of various compositions and structures, which are globally distributed in water.
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Affiliation(s)
- Runzi Cao
- Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, People's Republic of China.
| | - Xinna Liu
- Beijing Key Laboratory of Grape Science and Enology and Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, People's Republic of China; Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, People's Republic of China
| | - Jiajun Duan
- Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, People's Republic of China
| | - Bowen Gao
- Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, People's Republic of China
| | - Xiaosong He
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, People's Republic of China
| | - Yang Li
- Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, People's Republic of China.
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19
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Zhang T, Cheng F, Yang H, Zhu B, Li C, Zhang YN, Qu J, Peijnenburg WJGM. Photochemical degradation pathways of cell-free antibiotic resistance genes in water under simulated sunlight irradiation: Experimental and quantum chemical studies. CHEMOSPHERE 2022; 302:134879. [PMID: 35551936 DOI: 10.1016/j.chemosphere.2022.134879] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/29/2022] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
The presence of antibiotic resistance genes (ARGs) in the environment poses a threat to human health and therefore their environmental behavior needs to be studied urgently. A systematic study was conducted on the photodegradation pathways of the cell-free tetracycline resistance gene (Tc-ARG) under simulated sunlight irradiation. The results showed that Tc-ARG can undergo direct photodegradation, which significantly reduces its horizontal transfer efficiency. Suwannee River fulvic acid (SRFA) promoted the photodegradation of Tc-ARG and further inhibited its horizontal transfer by generating reactive intermediates. The photodegradation of Tc-ARG was attributed to degradation of the four bases (G, C, A, T) and the deoxyribose group. Quantum chemical calculations showed that the four bases could be oxidized by the hydroxyl radical (HO) through addition and H-abstraction reactions. The main oxidative product 8-oxo-dG was detected. This product was generated through the addition reaction of G-C with HO, subsequent to dissolved oxygen initiated H-abstraction and H2O catalyzed H-transfer reactions. The predicted maximum photodegradation rates of Tc-ARG in the Yellow River estuary were 0.524, 0.937, and 0.336 h-1 in fresh water, estuary water, and seawater, respectively. This study furthermore revealed the microscopic photodegradation pathways and obtained essential degradation parameters of Tc-ARG in sunlit surface water.
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Affiliation(s)
- Tingting Zhang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Fangyuan Cheng
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Hao Yang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Boyi Zhu
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Chao Li
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Ya-Nan Zhang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, 130117, China.
| | - Jiao Qu
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, 130117, China.
| | - Willie J G M Peijnenburg
- Institute of Environmental Sciences, Leiden University, Leiden, the Netherlands; National Institute of Public Health and the Environment (RIVM), Center for Safety of Substances and Products, Bilthoven, the Netherlands
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20
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Qiu X, Ma S, Zhang J, Fang L, Guo X, Zhu L. Dissolved Organic Matter Promotes the Aging Process of Polystyrene Microplastics under Dark and Ultraviolet Light Conditions: The Crucial Role of Reactive Oxygen Species. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:10149-10160. [PMID: 35793149 DOI: 10.1021/acs.est.2c03309] [Citation(s) in RCA: 78] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Microplastics (MPs) interact frequently with dissolved organic matter (DOM) commonly found in the environment, but information on the aging behavior of MPs under the participation of DOM is still lacking. Thus, the polystyrene microplastic (PSMP) aging process with DOM participation was systematically studied by electron paramagnetic resonance spectroscopy, high-performance liquid chromatography, Fourier transform infrared (FTIR) spectroscopy, and two-dimensional correlation spectroscopy analyses under dark and ultraviolet (UV) light conditions. DOM was found to promote electron transfer to generate reactive oxygen species (ROS) under dark conditions and the aging of PSMPs, while the process of DOM generating ROS under UV light was more susceptible to photoelectrons and accelerated the aging process of PSMPs. However, among the four DOM types, fulvic acid (FA) has a more significant promoting effect on the aging process of PSMPs than humic acid, which can be attributed to the stronger conversion ability of FA to semiquinone radicals. Density functional theory calculations are used to describe the difference in the aging process of different structures of plastics with the participation of DOM. This study provides a necessary theoretical basis for the study of the migration of MPs in groundwater and deep surface water.
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Affiliation(s)
- Xinran Qiu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
- Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, 712100 China
| | - Sirui Ma
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
- Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, 712100 China
| | - Jianxiang Zhang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Linchuan Fang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
- Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, 712100 China
| | - Xuetao Guo
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
- Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, 712100 China
| | - Lingyan Zhu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
- Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, 712100 China
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21
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Luo J, Zhou Q, Hu X, Zeng H, Deng P, He C, Shi Q. Lake Chemodiversity Driven by Natural and Anthropogenic Factors. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:5910-5919. [PMID: 35389635 DOI: 10.1021/acs.est.1c08148] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
As extremely active sites processing terrestrially derived dissolved organic matter (DOM), lakes deserve sufficient attention. Because of high-complexity interactions between DOM and the surrounding environment, the natural and anthropogenic drivers controlling the composition and chemodiversity of DOM molecules in lakes remain unclear. Here, 13,952 DOM molecules were identified and assessed in 45 lakes across China via ultrahigh-resolution mass spectrometry. Furthermore, the effects of both natural and anthropogenic factors on the DOM composition, DOM chemodiversity, and greenhouse gas emissions were investigated. The majority of the variations in DOM chemical composition could be attributed to the differences in the hydrology and nutrient concentrations of the lakes, and human activities also played a role, mainly through atmospheric pollution. Environmental factors mainly influenced DOM chemodiversity in the form of S-containing compounds. N-containing compounds exhibited a positive correlation with CO2 emissions, while N- and S-free compounds exhibited a positive correlation with N2O emissions. These results facilitate a comprehensive understanding of the interactions between lake DOM and the surrounding environment, thereby providing a reference for the formulation of strategies aimed at the harmonious development of human and natural environments.
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Affiliation(s)
- Jiwei Luo
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Qixing Zhou
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Xiangang Hu
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Hui Zeng
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Peng Deng
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Chen He
- State Key Laboratory of Heavy Oil Processing, Petroleum Molecular Engineering Center (PMEC), China University of Petroleum, Beijing 102249, China
| | - Quan Shi
- State Key Laboratory of Heavy Oil Processing, Petroleum Molecular Engineering Center (PMEC), China University of Petroleum, Beijing 102249, China
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22
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Yan W, Chen Y, Han L, Sun K, Song F, Yang Y, Sun H. Pyrogenic dissolved organic matter produced at higher temperature is more photoactive: Insight into molecular changes and reactive oxygen species generation. JOURNAL OF HAZARDOUS MATERIALS 2022; 425:127817. [PMID: 34883369 DOI: 10.1016/j.jhazmat.2021.127817] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/04/2021] [Accepted: 11/14/2021] [Indexed: 06/13/2023]
Abstract
Pyrogenic dissolved organic matter (pyDOM) is the photolabile fraction in the dissolved organic matter pool. However, the molecular changes and reactive oxygen species generation of pyDOMs under continuous irradiation, and how these vary with feedstock type and pyrolysis temperature, are not well understood. In this study, the soluble fractions of 300 and 450 ºC biochars (pyDOM300 and pyDOM450) were subjected to photo-irradiation. PyDOM450 was of higher aromaticity, molecular variety, but lower unsaturation than pyDOM300. The molecular weight, aromaticity, and double bond equivalents of pyDOMs generally decreased after photo-irradiation. The degradation pattern of pyDOMs can be divided into two stages. In the initial 24 h, pyDOM300 degraded faster than pyDOM450, with the more profound transformation of condensed aromatics and carbohydrate into aliphatic/proteins, lignins, and tannins in pyDOM300. After 720 h irradiation, however, the degradation ratio of pyDOM450 (36.2-43.9%) exceeded that of pyDOM300 (23.7-30.3%), with the initially preserved condensed aromatics in pyDOM450 further transforming into aliphatic/proteins and tannins. This was potentially attributed to the generation of more reactive oxygen species (·OH and 1O2) in pyDOM450. This study uncovered the photodegradation mechanisms of pyDOMs at molecular scale and helped to understand their cycling and effects on environment.
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Affiliation(s)
- Wenhui Yan
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Yalan Chen
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Lanfang Han
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Ke Sun
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Fanhao Song
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yan Yang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Haoran Sun
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
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23
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Zhang YN, Cheng F, Zhang T, Li C, Qu J, Chen J, Peijnenburg WJGM. Dissolved Organic Matter Enhanced the Aggregation and Oxidation of Nanoplastics under Simulated Sunlight Irradiation in Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:3085-3095. [PMID: 35174701 DOI: 10.1021/acs.est.1c07129] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Nanoplastics (NPs) have become a new type of pollutant of high concern that is ubiquitous in aqueous environments. However, the transport and transformation of NPs in natural waters are not yet fully understood. In this study, the aggregation and photooxidation of NPs were assessed with nanosized polystyrene (PS) as an example, and the effects of dissolved organic matter (DOM) were investigated with Suwannee River fulvic acid (SRFA) as representative DOM. The results showed that simulated sunlight irradiation exhibited negligible effects on the aggregation of PS, while SRFA enhanced its heteroaggregation through hydrophobic interactions. In SRFA solutions, photooxidation of PS with a particle size of 200 nm was observed, which led to an increase in the O/C ratio on its surface at a rate of (2.20 ± 0.40) × 10-2 h-1. This indicates the promotional effect of SRFA on the oxidation of nanosized PS, which is attributed to the generation of the excited triplet state (3SRFA*), hydroxyl radicals (•OH), and singlet oxygen (1O2). Among these reactive species, 1O2 played a crucial role in the oxidation of PS. The findings in this study are helpful for an in-depth understanding of the environmental behavior of NPs in natural waters.
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Affiliation(s)
- Ya-Nan Zhang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, P. R. China
| | - Fangyuan Cheng
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, P. R. China
| | - Tingting Zhang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, P. R. China
| | - Chao Li
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, P. R. China
| | - Jiao Qu
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, P. R. China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, P. R. China
| | - Willie J G M Peijnenburg
- Institute of Environmental Sciences, Leiden University, Leiden 2300 RA, The Netherlands
- National Institute of Public Health and the Environment (RIVM), Center for Safety of Substances and Products, Bilthoven 3720 BA, The Netherlands
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24
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Couch K, Leresche F, Farmer C, McKay G, Rosario-Ortiz FL. Assessing the source of the photochemical formation of hydroxylating species from dissolved organic matter using model sensitizers. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:102-115. [PMID: 34908096 DOI: 10.1039/d1em00345c] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Dissolved organic matter (DOM) is ubiquitous in natural waters and can facilitate the chemical transformation of many contaminants through the photochemical production of reactive intermediates, such as singlet oxygen (1O2), excited triplet state DOM (3DOM*), and hydroxylating species (˙OH and other intermediates of similar reaction chemistry). The formation mechanism of most reactive intermediates is well understood, but this is not the case for the formation of hydroxylating species from DOM. To investigate this chemistry, DOM model sensitizers were irradiated with two different probe compounds (benzene and benzoic acid) at two irradiation wavelengths (254 and 320 nm). The ability of DOM model sensitizers to hydroxylate these arene probes was assessed by measuring rates of formation of the hydroxylated probe compounds (phenol and salicylic acid). Multiple classes of model sensitizers were tested, including quinones, hydroxybenzoic acids, aromatic ketones, and other triplet forming species. Of these classes of model sensitizers, only quinones and hydroxybenzoic acids had a hydroxylating capacity. Methanol quenching experiments were used to assess the reactivity of hydroxylating species. These results have several implications for the systems tested. First, they suggest that the hydroxylating intermediate produced from hydroxybenzoic acid photolysis may not be hydroxyl radical, but a different hydroxylating species. Also, these data prompted investigation of whether quinone photoproducts have a hydroxylating capacity. These results confirm that hydroxybenzoic acids and quinones are important to the photochemical production of hydroxylating species from DOM, but the mechanism by which this occurs for these classes of sensitizers is still elusive.
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Affiliation(s)
- Kylie Couch
- Department of Civil, Environmental, and Architectural Engineering, Environmental Engineering Program, University of Colorado Boulder, 607 UCB, CO 80309, USA.
| | - Frank Leresche
- Department of Civil, Environmental, and Architectural Engineering, Environmental Engineering Program, University of Colorado Boulder, 607 UCB, CO 80309, USA.
| | - Claire Farmer
- Department of Civil, Environmental, and Architectural Engineering, Environmental Engineering Program, University of Colorado Boulder, 607 UCB, CO 80309, USA.
| | - Garrett McKay
- Zachry Department of Civil and Environmental Engineering, Texas A&M University, 3136 TAMU, College Station, TX 77843, USA.
| | - Fernando L Rosario-Ortiz
- Department of Civil, Environmental, and Architectural Engineering, Environmental Engineering Program, University of Colorado Boulder, 607 UCB, CO 80309, USA.
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25
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Wu B, Liu T, Wang Y, Zhao G, Chen B, Chu C. High Sample Throughput LED Reactor for Facile Characterization of the Quantum Yield Spectrum of Photochemically Produced Reactive Intermediates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:16204-16214. [PMID: 34553927 DOI: 10.1021/acs.est.1c04608] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Photochemically produced reactive intermediates (PPRIs) by natural photosensitizers such as chromophoric dissolved organic matter (CDOM) play numerous key roles in aquatic biogeochemical processes. PPRI productions rely on both the intensity and the spectrum of incident sunlight. While the impacts of sunlight intensity on PPRI productions are well-studied, there remains insufficient understanding of the spectrum-dependence of PPRI productions. Here we designed a high sample throughput reactor equipped with monochromatic LED lights for systematic assessments of wavelength-dependent productions of four important PPRI species, i.e., triplet-state excited CDOM (3CDOM*), singlet oxygen (1O2), hydrogen peroxide (H2O2), and hydroxyl radical (•OH), in CDOM solutions. The quantum yields of PPRIs followed the order: 3CDOM* > 1O2 ≫ H2O2 > •OH. Moreover, PPRI quantum yields decreased with the light wavelength increasing from 375 to 490 nm and sharply decreased to zero above 490 nm, while the shapes of quantum yield spectra differed among PPRI species. Simulations on PPRI productions under varying season, latitude, altitude, and cloud cover conditions show that the sunlight spectrum plays a role as equally important as intensity in determining PPRI productions and PPRI-mediated transformations of aquatic nutrients and micropollutants. Therefore, incorporating the spectrum dependence of PPRI productions will advance our understandings of PPRI-driven biogeochemical processes and pollutant dynamics under varying spatial-temporal and climatic conditions. Regarding this, the high sample throughput LED reactor sheds light on a new approach for the facile characterization of PPRI quantum yield spectrum.
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Affiliation(s)
- Binbin Wu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Tian Liu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Yanling Wang
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Guoqiang Zhao
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Baoliang Chen
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Chiheng Chu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
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26
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Kong Q, Fan M, Yin R, Zhang X, Lei Y, Shang C, Yang X. Micropollutant abatement and byproduct formation during the co-exposure of chlorine dioxide (ClO 2) and UVC radiation. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126424. [PMID: 34174627 DOI: 10.1016/j.jhazmat.2021.126424] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/08/2021] [Accepted: 06/15/2021] [Indexed: 06/13/2023]
Abstract
Photolysis of ClO2 by UVC radiation occurs in several drinking water treatment scenarios (e.g., pre-oxidation by ClO2 with post-UVC disinfection or a multi-barrier disinfection system comprising ClO2 and UVC disinfection in sequence). However, whether micropollutants are degraded and undesired byproducts are formed during the co-exposure of ClO2 and UVC radiation remain unclear. This study demonstrated that four micropollutants (trimethoprim, iopromide, caffeine, and ciprofloxacin) were degraded by 14.4-100.0% during the co-exposure of ClO2 and UVC radiation in the synthetic drinking water under the environmentally relevant conditions (UV dose of 207 mJ cm-2, ClO2 dose of 1.35 mg L-1, and pH of 7.0). Trimethoprim and iopromide were predominantly degraded by ClO2 oxidation and direct UVC photolysis, respectively. Caffeine and ciprofloxacin were predominantly degraded by the radicals (HO• and Cl•) and the in-situ formed free chlorine from ClO2 photolysis, respectively. The yields of total organic chlorine (12.5 µg L-1 from 1.0 mg C L-1 of NOM) and chlorate (0.14 mg L-1 From 1.35 mg L-1 of ClO2) during the co-exposure were low. However, the yield of chlorite was high (0.76 mg L-1 from 1.35 mg L-1 of ClO2), which requires attention and control.
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Affiliation(s)
- Qingqing Kong
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Mengge Fan
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Ran Yin
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
| | - Xinran Zhang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Yu Lei
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Chii Shang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Xin Yang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China.
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27
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Palma D, Khaled A, Sleiman M, Voyard G, Richard C. Effect of UVC pre-irradiation on the Suwannee river Natural Organic Matter (SRNOM) photooxidant properties. WATER RESEARCH 2021; 202:117395. [PMID: 34273776 DOI: 10.1016/j.watres.2021.117395] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
The present study aimed to investigate the changes in the chemical composition, and in the optical and photooxidant properties of Suwannee River Natural Organic Matter (SRNOM) induced by UVC (254 nm) treatment. The extent of the photodegradation was first assessed by UV-visible/fluorescence spectroscopies and organic carbon analysis. An in-depth investigation of the chemical changes was also conducted using liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry after derivatizations. A series of mono, di and tricarbonyls and mono and dicarboxylic acids in C1C6 were identified in samples irradiated from 1 to 4 h. After 3 h of irradiation, carbonyls accounted for 46% of the organic carbon remaining in solution whereas carboxylic acids represented about 2%. Then, we investigated the modifications of the photooxidant properties of SRNOM induced by these chemical changes. At 254 nm, UVC pre-irradiated SRNOM photodegraded glyphosate 29 times faster than original SRNOM and the reaction was fully inhibited by 2-propanol (5 × 10-3 M). This enhanced photooxidant properties at 254 nm toward glyphosate was therefore reasonably due to •OH radicals formation, as confirmed by additional ESR measurements. A mechanism involving a chain reaction was proposed based on independent experiments conducted on carbonyl compounds, particularly pyruvic acid and acetone. The findings of this study show that UVC pre-treatment of NOM can enhance the removal of water pollutants and suggests a possible integration of a NOM pre-activation step in engineered water treatment sytems.
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Affiliation(s)
- Davide Palma
- Université Clermont Auvergne, CNRS, SIGMA-Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Amina Khaled
- Université Clermont Auvergne, CNRS, SIGMA-Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Mohamad Sleiman
- Université Clermont Auvergne, CNRS, SIGMA-Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Guillaume Voyard
- Université Clermont Auvergne, CNRS, SIGMA-Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Claire Richard
- Université Clermont Auvergne, CNRS, SIGMA-Clermont, ICCF, F-63000 Clermont-Ferrand, France.
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28
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Wang Y, Fan L, Jones OAH, Roddick F. Quantification of seasonal photo-induced formation of reactive intermediates in a municipal sewage lagoon upon sunlight exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 765:142733. [PMID: 33572041 DOI: 10.1016/j.scitotenv.2020.142733] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/14/2020] [Accepted: 09/26/2020] [Indexed: 06/12/2023]
Abstract
Photochemically produced reactive oxygen species in wastewater lagoons upon sunlight exposure are important in the attenuation of emerging contaminants (ECs). The production of reactive radicals in wastewater lagoons depends on both environmental factors and the composition of effluent organic matter (EfOM) in the wastewater. Knowing the steady state concentrations of these reactive species produced in a particular lagoon wastewater is critical to the prediction of the persistence and attenuation of ECs in that sunlit wastewater treatment lagoon. This study quantified the formation of four photochemically produced reactive intermediates (PPRIs): hydroxyl radical, carbonate radical, singlet oxygen, and triplet excited state EfOM in 11 samples collected from a municipal wastewater lagoon over a full year. The temporal distribution of these key PPRIs in the lagoon under investigation was determined in relation to sunlight irradiance, wastewater composition and temperature. Greater sunlight intensity led to greater PPRI production over the year. Increasing wastewater temperature from 12 to 25 °C led to greater production of singlet oxygen, a moderate decrease in hydroxyl radical and increase in triplet excited state EfOM, and minimal impact on carbonate radical production. The optical properties of the lagoon wastewater of Napierian absorption coefficient (A300) and E2:E3 ratio could be used as indicators of the formation of singlet oxygen (Pearson's r = 0.79) and triplet excited EfOM (Pearson's r = 0.76) produced upon solar irradiation. The concentration of carbonate radical formed was strongly correlated to the nitrate level in the wastewater (Pearson's r = 0.85). The findings could be used for modelling the seasonal sunlight-induced photolysis process of ECs during lagoon-based wastewater treatment, with a view to optimising the treatment process, predicting the efficacy of EC removal, and risk assessment of the treated water.
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Affiliation(s)
- Yufei Wang
- School of Engineering, RMIT University, GPO Box 2476, Melbourne, Victoria 3000, Australia
| | - Linhua Fan
- School of Engineering, RMIT University, GPO Box 2476, Melbourne, Victoria 3000, Australia
| | - Oliver A H Jones
- School of Science, RMIT University, Bundoora West Campus, PO Box 71, Bundoora, Victoria 3083, Australia
| | - Felicity Roddick
- School of Engineering, RMIT University, GPO Box 2476, Melbourne, Victoria 3000, Australia.
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29
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Yi K, Lei M, Peng L, Chen A, Luo S. Sunlight-driven degradation of diethyl phthalate via magnetically modified biochar catalysts in water: Internal electron transfer mechanism. CHEMOSPHERE 2021; 269:129366. [PMID: 33385662 DOI: 10.1016/j.chemosphere.2020.129366] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/13/2020] [Accepted: 12/15/2020] [Indexed: 06/12/2023]
Abstract
This study presents a one-step synthetic approach for magnetic biochar (MBC) photo-degradation of diethyl phthalate (DEP). The results showed that MBC exhibited better catalytic property for DEP degradation than BC, and its catalytic performance was influenced by the amount of Fe doping. Electron paramagnetic resonance (EPR), quenching experiments, and chemical probe studies confirmed the presence of persistent free radicals (PFRs), hydroxyl radicals (·OH), and superoxide anion radical (·O2-) in both of BC and MBC. Solar light promoted the formation of PFRs in BC system, which transferred electrons to oxygen to form ·O2-, thus yielding ·OH. On the other hand, electron transfer occurred between PFRs and Fe3+ for MBC, Fe2+ played an important role in activation of O2 and ·O2- production. Subsequently, photo-Fenton reaction was primarily responsible for ·OH formation. This work compared the different generation pathways for ROS between BC and MBC and provides new insight into the possible mediatory roles of BC in O2 activation under solar light by transition metals.
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Affiliation(s)
- Kexin Yi
- College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, PR China; College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China
| | - Ming Lei
- College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, PR China
| | - Liang Peng
- College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, PR China
| | - Anwei Chen
- College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, PR China
| | - Si Luo
- College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, PR China.
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30
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Yang X, Yuan J, Yue FJ, Li SL, Wang B, Mohinuzzaman M, Liu Y, Senesi N, Lao X, Li L, Liu CQ, Ellam RM, Vione D, Mostofa KMG. New insights into mechanisms of sunlight- and dark-mediated high-temperature accelerated diurnal production-degradation of fluorescent DOM in lake waters. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 760:143377. [PMID: 33198994 DOI: 10.1016/j.scitotenv.2020.143377] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
The production of fluorescent dissolved organic matter (FDOM) by phytoplankton and its subsequent degradation, both of which occur constantly under diurnal-day time sunlight and by night time dark-microbial respiration processes in the upper layer of surface waters, influence markedly several biogeochemical processes and functions in aquatic environments and can be feasibly related to global warming (GW). In this work sunlight-mediated high-temperature was shown to accelerate the production of FDOM, but also its complete disappearance over a 24-h diurnal period in July at the highest air and water temperatures (respectively, 41.1 and 33.5 °C), differently from lower temperature months. Extracellular polymeric substances (EPS), an early-state DOM, were produced by phytoplankton in July in the early morning (6:00-9:00), then they were degraded into four FDOM components over midday (10:00-15:00), which was followed by simultaneous production and almost complete degradation of FDOM with reformation of EPS during the night (2:00-6:00). Such transformations occurred simultaneously with the fluctuating production of nutrients, dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and the two isotopes (δ15N and δ18O) of NO3-. It was estimated that complete degradation of FDOM in July was associated with mineralization of approximately 15% of the initial DOC, which showed a nighttime minimum (00:00) in comparison to a maximum at 13:00. FDOM identified by excitation-emission matrix spectroscopy combined with parallel factor analysis consisted of EPS, autochthonous humic-like substances (AHLS) of C- and M-types, a combined form of C- and M-types of AHLS, protein-like substances (PLS), newly-released PLS, tryptophan-like substances, tyrosine-like substances (TYLS), a combined form of TYLS and phenylalanine-like substances (PALS), and their degradation products. Finally, stepwise degradation and production processes are synthesized in a pathway for FDOM components production and their subsequent transformation under different diurnal temperature conditions, which provided a broader paradigm for future impacts on GW-mediated DOM dynamics in lake water.
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Affiliation(s)
- Xuemei Yang
- Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Jie Yuan
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beitucheng Western Road, Chaoyang District, 100029 Beijing, PR China
| | - Fu-Jun Yue
- Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Si-Liang Li
- Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Baoli Wang
- Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Mohammad Mohinuzzaman
- Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Yijun Liu
- Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Nicola Senesi
- Dip.to di Scienze del Suolo, della Pianta e degli Alimenti, Università degli Studi di Bari "Aldo Moro", Via G. Amendola 165/A, 70126 Bari, Italy
| | - Xinyu Lao
- Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Longlong Li
- Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Cong-Qiang Liu
- Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Rob M Ellam
- Scottish Universities Environmental Research Centre, Rankine Avenue, Scottish Enterprise Technology Park, East Kilbride G75 0QF, UK; Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Davide Vione
- Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy; Centro Interdipartimentale NatRisk, Via Leonardo da Vinci 44, 10095 Grugliasco, TO, Italy
| | - Khan M G Mostofa
- Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, 92 Weijin Road, Tianjin 300072, China.
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Liu S, Tan M, Ge L, Zhu F, Wu S, Chen N, Zhu C, Zhou D. Photooxidation mechanism of As(III) by straw-derived dissolved organic matter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:144049. [PMID: 33316532 DOI: 10.1016/j.scitotenv.2020.144049] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 06/12/2023]
Abstract
Straw return-to-field is a common agronomic practice that would affect the physicochemical characteristics of the paddy soil and overlying water, but few studies have focused on the possible impacts of straw return on the conversion of pollutants. In this study, the photooxidation of As(III) in aqueous solution by straw-derived dissolved organic matter (S-DOM) was investigated. The results showed that dissolved organic matter derived from wheat straw (DOMws) and rape straw (DOMrs) exhibited good spectroscopic features and could efficiently oxidize As(III) under irradiation at pH 5.0, with the kobs values of As(III) oxidation being 0.15 h-1 and 0.17 h-1 for DOMws and DOMrs, respectively. Quenching studies indicated that hydroxyl radical (OH) dominated the oxidation of As(III) for both types of dissolved organic matter (DOM), though singlet oxygen (1O2) also played a role in the DOMrs system. Since acidic conditions are favorable for the formation of OH, As(III) oxidation decreased with an increase of pH value. Additionally, the oxidation efficiency of As(III) was inhibited in the presence of NO3- (0.2-2 mM) while enhanced in the presence of Fe(III) (5-50 μM). This study is of great significance for understanding the removal/transformation behavior of pollutants in paddy fields that receive straw return.
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Affiliation(s)
- Shaochong Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Mengxi Tan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Liqiang Ge
- Geological Survey of Jiangsu Province, Nanjing 210018, PR China
| | - Fengxiao Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Song Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Ning Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Changyin Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
| | - Dongmei Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
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Wang L, Chen Y, Chen B, Yang J. Generation of hydroxyl radicals during photodegradation of chloroacetic acids by 254 nm ultraviolet: A special degradation process revealed by a holistic radical determination methodology. JOURNAL OF HAZARDOUS MATERIALS 2021; 404:124040. [PMID: 33157519 DOI: 10.1016/j.jhazmat.2020.124040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/21/2020] [Accepted: 09/16/2020] [Indexed: 06/11/2023]
Abstract
Upon ultraviolet (UV) irradiation, aqueous contaminants may undergo direct and/or indirect photolysis. Direct photolysis refers to transformation of contaminants by UV photon, and indirect photolysis refers to degradation of contaminants by UV-induced reactive species in the presence of photosensitizers. Because hydroxyl radical (•OH) was unexpectedly observed during chloroacetic acids photolysis without using photosensitizer, a question arises regarding whether direct photolysis-induced indirect photolysis (DPIP) was present and how it originated and evolved along the process. To answer these questions, this study employed multiple different yet complementary •OH detection approaches (i.e., probe, scavenger, electron paramagnetic resonance, and hydroxylation products) to prove the presence and role of •OH. Given that hydrogen peroxide (H2O2) was produced only in oxygenated water but not in deoxygenated water, we revealed that •OH was mainly generated by reduced oxygen. Meanwhile, several photolysis products like formate, glycolic acid, and glyoxylic acid were able to yield H2O2 too, suggesting that they can all trigger formation of •OH under 254 nm UV. In addition to evidences of DPIP phenomenon, this study is also novel in demonstrating a holistic methodology to prove and identify the presence and sources of radicals, which might help enhance understandings of UV processes.
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Affiliation(s)
- Lei Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Shenzhen 518055, China
| | - Yi Chen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Shenzhen 518055, China
| | - Baiyang Chen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Shenzhen 518055, China.
| | - Jie Yang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Shenzhen 518055, China
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Wang Z, Lv J, Zhang S, Christie P, Zhang S. Interfacial Molecular Fractionation on Ferrihydrite Reduces the Photochemical Reactivity of Dissolved Organic Matter. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:1769-1778. [PMID: 33494598 DOI: 10.1021/acs.est.0c07132] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The selective sorption of dissolved organic matter (DOM) on minerals is a widespread geochemical process in the natural environment. Recent studies have explored the influence of this process on the molecular fractionation of DOM at water-mineral interfaces. However, it remains unclear how molecular fractionation affects the photochemistry of DOM. Here, we demonstrate that the adsorptive fractionation of DOM on ferrihydrite greatly reduces its photoproduction of reactive oxygen species (ROS) including 1O2, O2•-, and •OH normalized to organic carbon (ROSOC). The ROSOC for 1O2, O2•-, and •OH were positively correlated with the abundances of polyphenols and oxygenated polycyclic aromatics, which were also observed using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis to be preferentially sequestered by ferrihydrite. The molecules that preferentially remained in the solution after adsorption displayed low levels of ROSOC. The molecular fractionation of DOM induced by adsorption on ferrihydrite therefore influenced the molecular components and also significantly reduced the photoreactive fractions of DOM in waters. These results are very important in promoting our understanding of the effects of molecular fractionation on the biogeochemical features, behaviors, and implications of DOM in the environment.
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Affiliation(s)
- Zhe Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of the Chinese the Academy of Sciences, Beijing 100049, China
| | - Jitao Lv
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Suhuan Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of the Chinese the Academy of Sciences, Beijing 100049, China
| | - Peter Christie
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Shuzhen Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of the Chinese the Academy of Sciences, Beijing 100049, China
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Xi N, Li Y, Chen J, Yang Y, Duan J, Xia X. Elevated Temperatures Decrease the Photodegradation Rate of Pyrethroid Insecticides on Spinach Leaves: Implications for the Effect of Climate Warming. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:1167-1177. [PMID: 33356194 DOI: 10.1021/acs.est.0c06959] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Climate warming is seldom considered in the transformation of pesticides on a plant leaf. This study investigated the effects of photodegradation temperature and spinach growth temperature from 15 to 21 °C on the photodegradation of bifenthrin, cypermethrin, fenvalerate, and deltamethrin on spinach leaves under xenon lamp irradiation in climate incubators. The photodegradation temperature had minor effects on pyrethroid photodegradation. Interestingly, the photodegradation rates decreased with increasing spinach growth temperature. For example, the photodegradation rate constant of bifenthrin on a spinach cultivated at 15 °C (3.73 (±0.59, 95% confidence level) × 10-2 h-1) was 1.9 times higher than that at 21 °C (1.96 (±0.17) × 10-2 h-1). Hydroxyl radicals (·OH) played a dominant role in the photodegradation. We speculate that ·OH originated from the degradation of hydroperoxide that was formed by oxidation of phenolic CH═CH, aliphatic CH3 and aromatic C-O-C, and subsequent hydrogen abstraction. The contents of these functional groups decreased with increasing growth temperature, which resulted in lower photodegradation rates at higher growth temperatures. A possible photodegradation pathway including ester bond cleavage, decyanation, and phenyl group removal was proposed. This work provides new insight into the effects of climate warming on the generation of reactive oxygen species and the transformation of pesticides on a plant leaf.
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Affiliation(s)
- Nannan Xi
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Yang Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Jian Chen
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Yixiao Yang
- The International Department, The Experimental High School Attached to Beijing Normal University, Beijing 100875, People's Republic of China
| | - Jiajun Duan
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Xinghui Xia
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, People's Republic of China
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Sun J, Ma J, Lian L, Yan S, Song W. Photochemical Formation of Methylhydroperoxide in Dissolved Organic Matter Solutions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:1076-1087. [PMID: 33373203 DOI: 10.1021/acs.est.0c07717] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Although it is known that the solar irradiation of chromophoric dissolved organic matter (CDOM) solutions generates H2O2, whether or not organic hydroperoxides (ROOHs) are photochemically formed remains unclear. This study employs high-performance liquid chromatography with the postcolumn enzymatic derivatization method to examine whether ROOHs can be formed in CDOM solutions under simulated solar irradiation. Methylhydroperoxide (MHP) is the only identified ROOH under our experimental conditions, and the quantum yields of MHP (ΦMHP) vary from (1.09 ± 0.09) × 10-6 to (4.95 ± 0.11) × 10-6 in the tested CDOM solutions, including four reference natural organic matters and two effluent organic matters. The quantum yields of H2O2 (ΦH2O2) are simultaneously measured, and the ratios of ΦH2O2 to ΦMHP range from 147 to 676. The formation of MHP is highly related to the presence of superoxide radical ions (O2•-) and methyl radicals (CH3•); therefore, a photoformation mechanism of MHP has been proposed. The photochemically generated CH3• reacts with O2 to yield CH3OO•. Subsequently, CH3OO• is reduced to MHP by O2•-. Our results also suggest that the yield of CH3• to MHP under air-saturated conditions is 52% and increases to 98% under oxygen-saturated conditions. The decays of MHP and H2O2 are very similar in terms of photodegradation, hydrolysis, Fenton, and photo-Fenton reactions. This study can be useful to understand the photochemical formation of organic peroxides in surface waters.
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Affiliation(s)
- Jiaqian Sun
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, P. R. China
| | - Jianzhong Ma
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, P. R. China
| | - Lushi Lian
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, P. R. China
| | - Shuwen Yan
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, P. R. China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P. R. China
| | - Weihua Song
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, P. R. China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P. R. China
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Liu Y, Wang T, Fang X, Deng Y, Cheng H, Bacha AUR, Nabi I, Zhang L. Brown carbon: An underlying driving force for rapid atmospheric sulfate formation and haze event. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 734:139415. [PMID: 32464390 DOI: 10.1016/j.scitotenv.2020.139415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/04/2020] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
The rapid sulfate formation is a crucial factor determining the explosive growth of fine particles and the frequent occurrence of severe haze events in China. Recent field observations also show that brown carbon is one of the most critical components in aerosol particles sampled during haze episodes. To this day, there is limited knowledge that accesses the role of brown carbon in atmospheric chemistry. In fact, these carbonaceous particulate matters, mainly derived from forest fires, biomass burning, and biogenic release, can act as photosensitizers and produce varieties of active intermediates to alter oxidation capacity. Experimental results in this work provide evidence that hydroxyl radical (∙OH) stems from brown carbon proxies fulvic acid /humic acid (FA/HA) upon irradiation, leading to rapid SO2 oxidation on brown carbon particles in the atmosphere. Further correlation analyses for sulfate formation and chromophore properties of 12 model compounds demonstrate that brown carbon particles with higher aromaticity and E2/E3 (the ratio of absorbance at 254 nm to that at 365 nm) would facilitate ∙OH production and SO2 photo-oxidation. Uptake coefficient measurements and sulfate production rate estimation indicate that brown carbon could gain importance in atmospheric SO2 oxidation. A better understanding of SO2 uptake kinetics on brown carbon surfaces favors in defining new regulations to improve air quality and reduce the harmful effects of haze events on resident health and the environment.
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Affiliation(s)
- Yangyang Liu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Tao Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Xiaozhong Fang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Yue Deng
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Hanyun Cheng
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Aziz-Ur-Rahim Bacha
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Iqra Nabi
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Liwu Zhang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China..
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Wasswa J, Driscoll CT, Zeng T. Photochemical Characterization of Surface Waters from Lakes in the Adirondack Region of New York. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:10654-10667. [PMID: 32786602 DOI: 10.1021/acs.est.0c02811] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The Adirondack Mountain region of New York, a historical hotspot for atmospheric sulfur and nitrogen deposition, features abundant lakes that are experiencing browning associated with recovery from acidification. Yet, much remains unknown about the photoreactivity of Adirondack lake waters. We quantified the apparent quantum yields (Φapp,RI) of photochemically produced reactive intermediates (RIs), such as excited triplet states of dissolved organic matter (3DOM*), singlet oxygen (1O2), and hydroxyl radicals (•OH), for surface waters collected from 16 representative Adirondack lakes. Φapp,3DOM* and Φapp,1O2 for native Adirondack lake waters fell within ranges reported for whole waters and DOM isolates from various sources, while Φapp,•OH were substantially lower than those measured for other aquatic samples. Orthogonal partial least squares and multiple linear regression analyses identified the spectral slope coefficient from 290 to 400 nm (S290-400) as the most effective predictor of Φapp,RI among measured water chemistry parameters and bulk DOM properties. Φapp,RI also exhibited divergent responses to controlled pH adjustment and aluminum or iron addition simulating hypothetical scenarios relevant to past and future water chemistry conditions of Adirondack lakes. This study highlights the need for continued research on changes in photoreactivity of acid-impacted aquatic ecosystems in response to browning and subsequent impacts on photochemical processes.
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Affiliation(s)
- Joseph Wasswa
- Department of Civil and Environmental Engineering, Syracuse University, 151 Link Hall, Syracuse, New York 13244, United States
| | - Charles T Driscoll
- Department of Civil and Environmental Engineering, Syracuse University, 151 Link Hall, Syracuse, New York 13244, United States
| | - Teng Zeng
- Department of Civil and Environmental Engineering, Syracuse University, 151 Link Hall, Syracuse, New York 13244, United States
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Jiang J, Zhao H, Xia D, Li X, Qu B. Formation of free radicals by direct photolysis of halogenated phenols (HPs) and effects of DOM: A case study on monobromophenols. JOURNAL OF HAZARDOUS MATERIALS 2020; 391:122220. [PMID: 32050140 DOI: 10.1016/j.jhazmat.2020.122220] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/31/2020] [Accepted: 02/01/2020] [Indexed: 06/10/2023]
Abstract
The free radicals play an important role to understand direct/indirect transformation mechanisms of organic pollutants. However, very few efforts have been made to elucidate the radicals produced by direct photolysis. In this study, the short-lived radicals generated under simulated sunlight irradiation from representative halogenated phenols (HPs), monobromophenols, were investigated by electron paramagnetic resonance (EPR). The results showed that three radicals, carbon-centered radical (C), hydrogen radical (H) and hydroxyl radical (OH), were generated from the direct irradiation of HPs. Compared to other substitutions, halogenated atom at para-position led to the highest production of these radicals which is in accordance with the energies calculated by density functional theory. Based on the analyses of the reactive species and corresponding intermediate adducts, the possible reaction pathways for these radicals were tentatively proposed. Dissolved organic matters (DOM) could enhance the photodegradation of HPs by directly affecting the radicals' formation, mainly due to generation of excited triplet DOM (3DOM*). A positive correlation was found between the concentrations of hydrated electron and the steady state 3DOM* from different DOM. Our findings provided insights into environmental photochemical fate of HPs through their direct photolysis and will help more accurately understand their phototransformation mechanisms in the environment.
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Affiliation(s)
- Jingqiu Jiang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116023, China
| | - Hongxia Zhao
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116023, China.
| | - Deming Xia
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116023, China
| | - Xintong Li
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116023, China
| | - Baocheng Qu
- College of Marine Technology and Environment, Dalian Ocean University, Dalian 116024, China.
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Chen Y, Hozalski RM, Olmanson LG, Page BP, Finlay JC, Brezonik PL, Arnold WA. Prediction of Photochemically Produced Reactive Intermediates in Surface Waters via Satellite Remote Sensing. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:6671-6681. [PMID: 32383589 DOI: 10.1021/acs.est.0c00344] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Absorption of solar radiation by colored dissolved organic matter (CDOM) in surface waters results in the formation of photochemically produced reactive intermediates (PPRIs) that react with pollutants in water. Knowing the steady-state concentrations of PPRIs ([PPRI]ss) is critical to predicting the persistence of pollutants in sunlit surface waters. CDOM levels (a440) can be measured remotely for lakes over large areas using satellite imagery. Laboratory measurements of [PPRI]ss and apparent quantum yields (Φ) of three PPRIs (3DOM*, 1O2, and •OH) were made for 24 lake samples under simulated sunlight. The total rate of light absorption by the water samples (Ra), the rates of formation (Rf), and [PPRI]ss of 3DOM* and 1O2 linearly increased with increasing a440. The production rate of •OH was linearly correlated with a440, but the steady-state concentration was best fit by a logarithmic function. The relationship between measured a440 and Landsat 8 reflectance was used to map a440 for more than 10 000 lakes across Minnesota. Relationships of a440 with Rf, [PPRIs]ss, and Ra were coupled with satellite-based a440 assessments to map reactive species production rates and concentrations as well as contaminant transformation rates. This study demonstrates the potential for using satellite imagery for estimating contaminant loss via indirect photolysis in lakes.
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Affiliation(s)
- Yiling Chen
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, United States
| | - Raymond M Hozalski
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, United States
| | - Leif G Olmanson
- Department of Forest Resources, University of Minnesota, 1530 Cleveland Avenue North, St. Paul, Minnesota 55108-6112, United States
| | - Benjamin P Page
- Water Resources Center, University of Minnesota, 1985 Buford Avenue, St. Paul, Minnesota 55108-6112, United States
| | - Jacques C Finlay
- Department of Ecology, Evolution, and Behavior, University of Minnesota, 1987 Upper Buford Circle, St. Paul, Minnesota 55108-6097, United States
| | - Patrick L Brezonik
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, United States
| | - William A Arnold
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, United States
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40
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Effect of dissociation constant (pKa) of natural organic matter on photo-generation of reactive oxygen species (ROS). J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2019.112345] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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41
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Liu Y, Yan S, Lian L, Ma J, Zhou H, Song W. Assessing the contribution of hydroxylation species in the photochemical transformation of primidone (pharmaceutical). THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 696:133826. [PMID: 31450049 DOI: 10.1016/j.scitotenv.2019.133826] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 07/24/2019] [Accepted: 08/06/2019] [Indexed: 06/10/2023]
Abstract
Pharmaceutical and personal care products (PPCPs) are a group of emerging contaminants that have frequently been detected in aqueous environments. Phototransformation driven by solar irradiation is one of the most important natural processes for the elimination of PPCPs. In this study, primidone (PMD) was chosen as a model "photorefractory" compound. A series of experiments were conducted to assess if reactive intermediates (RIs), such as hydroxyl radical (HO), singlet oxygen (1O2), and triplet states of dissolved organic matter (3DOM⁎), inhibited or enhanced the photochemical transformation of PMD under simulated solar irradiation. The results indicate that HO plays a key role in the photodegradation of PMD and that dissolved oxygen can affect the degradation rate of PMD by promoting HO formation. Our results demonstrated that PMD can not only react with free HO (HO-free) but also react with lower-energy hydroxylation agents (HO-like). The contributions of HO-free and HO-like to PMD degradation in various dissolved organic matter (DOM) solutions were estimated by a methane-quenching experiment. The results indicated that the HO-like species were important in the photodegradation of "photorefractory" compounds. The bimolecular reaction rate constant of the reaction of free HO with PMD was measured as (5.21 ± 0.02) × 109 M-1 s-1 by using electron pulse radiolysis. Furthermore, PMD was used as a probe to estimate the steady-state concentration of HO-free in various DOM solutions. Using the multivariate statistical strategies of orthogonal projection to latent structures discriminant analysis (OPLS-DA) and hierarchical clustering, 28 photochemical transformation products (TPs) of PMD were successfully identified from the DOM matrix.
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Affiliation(s)
- Yingjie Liu
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, PR China
| | - Shuwen Yan
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
| | - Lushi Lian
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, PR China
| | - Jianzhong Ma
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, PR China
| | - Huaxi Zhou
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, PR China
| | - Weihua Song
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
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42
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Berg SM, Whiting QT, Herrli JA, Winkels R, Wammer KH, Remucal CK. The Role of Dissolved Organic Matter Composition in Determining Photochemical Reactivity at the Molecular Level. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:11725-11734. [PMID: 31509695 DOI: 10.1021/acs.est.9b03007] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Dissolved organic matter (DOM) composition influences its ability to form photochemically produced reactive intermediates (PPRI). While relationships have been established between bulk DOM properties and triplet DOM (3DOM) and singlet oxygen (1O2) quantum yields, contradictory evidence exists for hydroxyl radical (•OH) and hydroxylating species. Furthermore, little is known about these relationships at the molecular level. We evaluated DOM composition and photochemical reactivity of water samples from a wastewater treatment plant and the St. Louis River in Minnesota and Wisconsin, U.S.A. Bulk characterization using ultraviolet-visible spectroscopy demonstrates that color and apparent size of DOM decrease downstream, while molecular composition analysis using Fourier-transform ion cyclotron resonance mass spectrometry reveals that saturation and chemodiversity is highest near Lake Superior. 3DOM quantum yield coefficients and 1O2 quantum yields increase downstream and correlate strongly with saturated formulas. Similar results are observed for carbon-normalized photodegradation rate constants of atorvastatin, carbamazepine, and venlafaxine, which react primarily with 3DOM and 1O2. In contrast, •OH quantum yields are lowest downstream and correlate with less saturated, more oxygenated DOM, suggesting that 3DOM is not its major precursor. Mixed relationships are observed for DEET, which reacts with multiple PPRI. Molecular-level compositional data reveal insights into the differing formation pathways of individual PPRI, but information about specific contaminants is needed to predict their photochemical fate.
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Affiliation(s)
- Stephanie M Berg
- Environmental Chemistry and Technology Program University of Wisconsin - Madison , Madison , Wisconsin 53706 , United States
| | - Quinn T Whiting
- Department of Chemistry University of St. Thomas , St. Paul , Minnesota 55105 , United States
| | - Joseph A Herrli
- Department of Chemistry University of St. Thomas , St. Paul , Minnesota 55105 , United States
| | - Ronan Winkels
- Department of Chemistry University of St. Thomas , St. Paul , Minnesota 55105 , United States
| | - Kristine H Wammer
- Department of Chemistry University of St. Thomas , St. Paul , Minnesota 55105 , United States
| | - Christina K Remucal
- Environmental Chemistry and Technology Program University of Wisconsin - Madison , Madison , Wisconsin 53706 , United States
- Department of Civil and Environmental Engineering University of Wisconsin - Madison , Madison , Wisconsin 53706 , United States
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43
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Zhou H, Yan S, Lian L, Song W. Triplet-State Photochemistry of Dissolved Organic Matter: Triplet-State Energy Distribution and Surface Electric Charge Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:2482-2490. [PMID: 30758190 DOI: 10.1021/acs.est.8b06574] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Excited triplet states of chromophoric dissolved organic matter (3CDOM*) are highly reactive species in sunlit surface waters and play a critical role in reactive oxygen species (ROS) formation and pollutant attenuation. In the present study, a series of chemical probes, including sorbic acid, sorbic alcohol, sorbic amine, trimethylphenol, and furfuryl alcohol, were employed to quantitatively determine 3CDOM* and 1O2 in various organic matters. Using a high concentration of sorbic alcohol as high-energy triplet states quencher, 3CDOM* can be first distinguished as high-energy triplet states (>250 kJ mol-1) and low-energy triplet states (<250 kJ mol-1). The terrestrial-origin natural organic matter (NOM) was found to mainly consist of low-energy triplet states, while high-energy triplet states were predominant in autochthonous-origin NOM and effluent/wastewater organic matter (EfOM/WWOM). The 1O2 quantum yields and electron transfer quantum yield coefficients ( fTMP) generated from low-energy triplet states remained constant in all tested organic matters. External phenolic compound showed quenching effects on triplet-state formation and tended to have a higher quenching efficiency for aromatic ketone triplet states, which are the main high-energy triplet states. In comparison with terrestrial-origin NOM, autochthonous-origin NOM and EfOM/WWOM presented lower reaction rate constants for sorbic amines and higher reaction rate constants for sorbic acid, and these differences are likely due to dissimilar surface electric charge conditions. Understanding the triplet-state photochemistry of CDOM is essential for providing useful insights into their photochemical effects in aquatic systems.
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Affiliation(s)
- Huaxi Zhou
- Department of Environmental Science & Engineering , Fudan University , Shanghai 200433 , P. R. China
| | - Shuwen Yan
- Department of Environmental Science & Engineering , Fudan University , Shanghai 200433 , P. R. China
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , P. R. China
| | - Lushi Lian
- Department of Environmental Science & Engineering , Fudan University , Shanghai 200433 , P. R. China
| | - Weihua Song
- Department of Environmental Science & Engineering , Fudan University , Shanghai 200433 , P. R. China
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , P. R. China
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44
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Stirchak LT, Moor KJ, McNeill K, Donaldson DJ. Differences in photochemistry between seawater and freshwater for two natural organic matter samples. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:28-39. [PMID: 30575831 DOI: 10.1039/c8em00431e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report changes in the excitation and resolved fluorescence spectra, inferred triplet formation and singlet oxygen formation abilities of two different Natural Organic Matter samples (NOM) in seawater vs. freshwater or NaCl solution. In artificial seawater solution (but not in NaCl solution), the natural water-derived NOM samples Suwannee River Natural Organic Matter (SRNOM) and Nordic Reservoir Natural Organic Matter (NRNOM) display large enhancements in fluorescence intensity. Nearly identical spectra are seen when seawater is replaced by solutions of Mg2+ at its seawater concentration, consistent with magnesium binding to ligand sites of the natural organic matter giving rise to different photophysics. Fluorescence anisotropy measurements show a decrease in anisotropy of SRNOM and NRNOM in seawater, also consistent with Mg2+ binding. Different effects of Mg2+ are seen when the different NOM samples are illuminated: NRNOM exhibits increased formation of its triplet state and also quenching of its triplet by oxygen, compared to its photochemistry in the absence of Mg2+, while SRNOM exhibits a reduction in triplet formation in the presence of Mg2+. These observations imply that the photochemistry of NOM in seawater may be very different from what is expected based on freshwater or NaCl solution measurements.
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45
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Kroflič A, Huš M, Grilc M, Grgić I. Underappreciated and Complex Role of Nitrous Acid in Aromatic Nitration under Mild Environmental Conditions: The Case of Activated Methoxyphenols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:13756-13765. [PMID: 30388370 DOI: 10.1021/acs.est.8b01903] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Many ambiguities surround the possible mechanisms of colored and toxic nitrophenols formation in natural systems. Nitration of a biologically and environmentally relevant aromatic compound, guaiacol (2-methoxyphenol), under mild aqueous-phase conditions (ambient temperatures, pH 4.5) was investigated by a temperature-dependent experimental modeling coupled to extensive ab initio calculations to obtain the activation energies of the modeled reaction pathways. The importance of dark nonradical reactions is emphasized, involving nitrous (HNO2) and peroxynitrous (HOONO) acids. Oxidation by HOONO is shown to proceed via a nonradical pathway, possibly involving the nitronium ion (NO2+) formation. Using quantum chemical calculations at the MP2/6-31++g(d,p) level, NO2• is shown capable of abstracting a hydrogen atom from the phenolic group on the aromatic ring. In a protic solvent, the corresponding aryl radical can combine with HNO2 to yield OH• and, after a subsequent oxidation step, nitrated aromatic products. The demonstrated chemistry is especially important for understanding the aging of nighttime atmospheric deliquesced aerosol. The relevance should be further investigated in the atmospheric gaseous phase. The results of this study have direct implications for accurate modeling of the burden of toxic nitroaromatic pollutants, and the formation of atmospheric brown carbon and its associated influence on Earth's albedo and climate forcing.
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Affiliation(s)
- Ana Kroflič
- Department of Analytical Chemistry , National Institute of Chemistry , Hajdrihova 19 , SI-1000 Ljubljana , Slovenia
| | - Matej Huš
- Department of Physics , Chalmers University of Technology , Fysikgränd 3 , SE-412 96 Gothenburg , Sweden
- Department of Catalysis and Chemical Reaction Engineering , National Institute of Chemistry , Hajdrihova 19 , SI-1000 Ljubljana , Slovenia
| | - Miha Grilc
- Department of Catalysis and Chemical Reaction Engineering , National Institute of Chemistry , Hajdrihova 19 , SI-1000 Ljubljana , Slovenia
- Institute of Chemical Technology , Leipzig University , Linnéstraße 3 , DE-04103 Leipzig , Germany
| | - Irena Grgić
- Department of Analytical Chemistry , National Institute of Chemistry , Hajdrihova 19 , SI-1000 Ljubljana , Slovenia
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46
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Giannakis S. Analogies and differences among bacterial and viral disinfection by the photo-Fenton process at neutral pH: a mini review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:27676-27692. [PMID: 29255985 DOI: 10.1007/s11356-017-0926-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/03/2017] [Indexed: 04/16/2023]
Abstract
Over the last years, the photo-Fenton process has been established as an effective, green alternative to chemical disinfection of waters and wastewaters. Microorganisms' inactivation is the latest success story in the application of this process at near-neutral pH, albeit without clearly elucidated inactivation mechanisms. In this review, the main pathways of the combined photo-Fenton process against the most frequent pathogen models (Escherichia coli for bacteria and MS2 bacteriophage for viruses) are analyzed. Firstly, the action of solar light is described and the specific inactivation mechanisms in bacteria (internal photo-Fenton) and viruses (genome damage) are presented. The contribution of the external pathways due to the potential presence of organic matter in generating reactive oxygen species (ROS) and their effects on microorganism inactivation are discussed. Afterwards, the effects of the gradual addition of Fe and H2O2 are assessed and the differences among bacterial and viral inactivation are highlighted. As a final step, the simultaneous addition of both reagents induces the photo-Fenton in the bulk, focusing on the differences induced by the homogeneous or heterogeneous fraction of the process and the variation among the two respective targets. This work exploits the accumulated evidence on the mechanisms of bacterial inactivation and the scarce ones towards viral targets, aiming to bridge this knowledge gap and make possible the further application of the photo-Fenton process in the field of water/wastewater treatment.
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Affiliation(s)
- Stefanos Giannakis
- School of Basic Sciences (SB), Institute of Chemical Science and Engineering (ISIC), Group of Advanced Oxidation Processes (GPAO), École Polytechnique Fédérale de Lausanne (EPFL), Station 6, 1015, Lausanne, Switzerland.
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47
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Zhang YN, Zhou Y, Qu J, Chen J, Zhao J, Lu Y, Li C, Xie Q, Peijnenburg WJGM. Unveiling the important roles of coexisting contaminants on photochemical transformations of pharmaceuticals: Fibrate drugs as a case study. JOURNAL OF HAZARDOUS MATERIALS 2018; 358:216-221. [PMID: 29990809 DOI: 10.1016/j.jhazmat.2018.06.068] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 06/25/2018] [Accepted: 06/29/2018] [Indexed: 06/08/2023]
Abstract
Pharmaceuticals are a group of ubiquitous emerging pollutants, many of which have been shown to undergo efficient photolysis in the environment. Photochemically produced reactive intermediates (PPRIs) sensitized by the pharmaceuticals in sunlit natural waters may induce photodegradation of coexisting compounds. In this study, the roles of coexisting contaminants on the phototransformation of pharmaceuticals were unveiled with the fibrate drugs gemfibrozil (GMF), fenofibrate (FNF), and fenofibric acid (FNFA) as model compounds. GMF undergoes initial concentration dependent photodegradation due to the involvement of singlet oxygen (1O2) initiated self-sensitized photolysis, and undergoes pH dependent photodegradation due to dissociation and hydroxyl radical (OH) generation. The decarboxylated intermediates of GMF and coexisting FNFA significantly accelerated the photodegradation of GMF. The promotional effects of the decarboxylated intermediates are attributed to generation of PPRIs, e.g. 1O2, superoxide (O2-), that subsequently react with GMF. Besides, FNFA can also promote the photodegradation of GMF through the electron transfer reaction from ground state GMF to excited state FNFA, leading to the formation of decarboxylated intermediates. The formed intermediates can subsequently also facilitate GMF photodegradation. The results presented here provided valuable novel insights into the effects of coexisting contaminants on the photodegradation of pharmaceuticals in polluted waters.
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Affiliation(s)
- Ya-Nan Zhang
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Yangjian Zhou
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Jiao Qu
- School of Environment, Northeast Normal University, Changchun 130117, China.
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jianchen Zhao
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Ying Lu
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Chao Li
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Qing Xie
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Willie J G M Peijnenburg
- Institute of Environmental Sciences, Leiden University, Leiden, The Netherlands; National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands
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48
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McKay G, Korak JA, Rosario-Ortiz FL. Temperature Dependence of Dissolved Organic Matter Fluorescence. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9022-9032. [PMID: 30028602 DOI: 10.1021/acs.est.8b00643] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The temperature dependence of organic matter fluorescence apparent quantum yields (Φf) was measured for a diverse set of organic matter isolates (i.e., marine aquatic, microbial aquatic, terrestrial aquatic, and soil) in aqueous solution and for whole water samples to determine apparent activation energies ( Ea) for radiationless decay processes of the excited singlet state. Ea was calculated from temperature dependent Φf data obtained by steady-state methods using a simplified photophysical model and the Arrhenius equation. All aquatic-derived isolates, all whole water samples, and one soil-derived fulvic acid isolate exhibited temperature dependent Φf values, with Ea ranging from 5.4 to 8.4 kJ mol-1 at an excitation wavelength of 350 nm. Conversely, soil humic acid isolates exhibited little or no temperature dependence in Φf. Ea varied with excitation wavelength in most cases, typically exhibiting a decrease between 350 and 500 nm. The narrow range of Ea values observed for these samples when compared to literature Ea values for model fluorophores (∼5-30 kJ mol-1) points to a similar photophysical mechanism for singlet excited states nonradiative inactivation across organic matter isolates of diverse source and character. In addition, this approach to temperature dependent fluorescence analysis provides a fundamental, physical basis, in contrast to existing empirical relationships, for correcting online fluorescence sensors for temperature effects.
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Affiliation(s)
- Garrett McKay
- Department of Civil, Environmental, and Architectural Engineering , University of Colorado , Boulder , Colorado 80309 , United States
| | - Julie A Korak
- Department of Civil, Environmental, and Architectural Engineering , University of Colorado , Boulder , Colorado 80309 , United States
| | - Fernando L Rosario-Ortiz
- Department of Civil, Environmental, and Architectural Engineering , University of Colorado , Boulder , Colorado 80309 , United States
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49
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Xu HY, Li B, Shi TN, Wang Y, Komarneni S. Nanoparticles of magnetite anchored onto few-layer graphene: A highly efficient Fenton-like nanocomposite catalyst. J Colloid Interface Sci 2018; 532:161-170. [PMID: 30081262 DOI: 10.1016/j.jcis.2018.07.128] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/25/2018] [Accepted: 07/29/2018] [Indexed: 11/16/2022]
Abstract
Developing a catalyst with high efficiency and recyclability is an important issue for the heterogeneous Fenton-like systems. In this study, magnetic Fe3O4 and reduced graphene oxide (RGO) nanocomposites were prepared by a facile alkaline-thermal precipitation method and employed as a highly effective heterogeneous Fenton-like catalyst for methyl orange (MO) degradation. Characterization of these nanocomposites by XRD, FTIR, Raman, FESEM and TEM revealed that nanoparticles (NPs) of Fe3O4 were tightly anchored on the few-layer RGO sheets. The anchoring of Fe3O4 NPs and the reduction of GO were achieved in one pot without adding any other reducing agents. Based on the measurements of GO surface Zeta potentials, a possible anchoring mechanism of Fe3O4 NPs onto RGO sheets was given. The Fe3O4/RGO nanocomposites exhibited much higher Fenton-like catalytic efficiency for MO degradation than pure Fe3O4 NPs. This degradation process followed the first-order kinetics model, where k1 and T complied with the Arrhenius equation with Ea of 12.79 kJ/mol and A of 8.20 s-1. Magnetic measurements revealed that Fe3O4/RGO nanocomposites were ferromagnetic as indicated by the presence of magnetic hysteresis loops. The Fe3O4/RGO nanocomposites showed good stability and recyclability. Hydroxyl radicals, OH were determined as the dominant oxidative species in Fe3O4/RGO-H2O2 system and the Fenton-like mechanism for MO degradation in water was proposed and discussed.
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Affiliation(s)
- Huan-Yan Xu
- School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, PR China; Materials Research Institute and Department of Ecosystem Science and Management, 204 Energy and the Environment Laboratory, The Pennsylvania State University, University Park, PA 16802, USA.
| | - Bo Li
- School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, PR China
| | - Tian-Nuo Shi
- School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, PR China
| | - Yuan Wang
- School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, PR China
| | - Sridhar Komarneni
- Materials Research Institute and Department of Ecosystem Science and Management, 204 Energy and the Environment Laboratory, The Pennsylvania State University, University Park, PA 16802, USA.
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50
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Wang Y, Roddick FA, Fan L. Direct and indirect photolysis of seven micropollutants in secondary effluent from a wastewater lagoon. CHEMOSPHERE 2017; 185:297-308. [PMID: 28704661 DOI: 10.1016/j.chemosphere.2017.06.122] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 06/27/2017] [Accepted: 06/28/2017] [Indexed: 06/07/2023]
Abstract
The photodegradation of seven micropollutants commonly found in municipal wastewater, namely caffeine, carbamazepine, diuron, simazine, sulfamethoxazole, triclosan and 2,4-D, was investigated in pure water and secondary effluent to understand the direct and indirect photolysis of these compounds under natural sunlight irradiation. Sulfamethoxazole and triclosan were readily photodegraded with half-lives of 5.8 and 1.8 h, respectively, whilst the others were relatively resistant towards sunlight irradiation. Enhanced degradation was observed in secondary effluent compared with in the pure water matrix for all compounds, except for triclosan. It was confirmed that hydroxyl radicals played an important role in the photodegradation of the micropollutants while singlet oxygen may also play a role. The contribution of hydroxyl radical to the overall degradation of the five compounds that were resistant to direct sunlight accounted for 32%-70%. The impact of humic acid and nitrate, two known photosensitisers and wastewater components, on the photodegradation of the seven micropollutants in pure water was investigated under simulated solar radiation. The presence of nitrate promoted the photochemical loss of all seven micropollutants, however, humic acid caused promotion or inhibition, depending on the characteristics of the micropollutant. Humic acid enhanced the photolytic degradation of caffeine, sulfamethoxazole and diuron, while it hindered the photodegradation of the other four compounds by absorbing the available irradiation energy and/or reforming the parent compound. Furthermore, it was shown that there was only a small increase (up to 15%) in photodegradation of the compounds at 25 °C compared with that at 10 °C in the simulated system.
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Affiliation(s)
- Yufei Wang
- School of Engineering, RMIT University, GPO Box 2476, Melbourne, VIC 3001, Australia
| | - Felicity A Roddick
- School of Engineering, RMIT University, GPO Box 2476, Melbourne, VIC 3001, Australia.
| | - Linhua Fan
- School of Engineering, RMIT University, GPO Box 2476, Melbourne, VIC 3001, Australia
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