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Zheng H, Zhang G, Zhang C, Zhang S. Unravelling structural features of small molecules for photochemical transformation of environmental contaminants. WATER RESEARCH 2024; 261:122015. [PMID: 38996734 DOI: 10.1016/j.watres.2024.122015] [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: 04/25/2024] [Revised: 06/07/2024] [Accepted: 06/27/2024] [Indexed: 07/14/2024]
Abstract
Small molecules, including natural metabolites, organic matter decomposition products, and engineered oxidation byproducts, are widespread in aquatic environment. However, the limited understanding of the photochemical interactions of these small molecules with water pollutants hampers the development of effective environmental protection strategies. This study explores the structural features governing the photochemical transformation of toxic oxyanions by α- and β-dicarbonyl compounds. By integrating experimental observations with quantum chemical calculations, a robust correlation network was constructed. The correlation network reveals that the reactivity of small organic molecules with oxyanions could be quantitively predicted by their intrinsic properties, such as electronic transition energy, bond dissociation energy, molecular softness, molecular orbital gap, atomic charge, and molecular surface local ionization energy. This network maps the relationship between the molecular architecture of chemicals and their photochemical behaviors. This perspective offers fresh insights into the photochemical behaviors of small molecules in diverse environmental and chemical contexts and are helpful for developing advanced water treatment strategies toward a sustainable future.
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Affiliation(s)
- Hongcen Zheng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Guoyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Chengyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
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2
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Wang X, Luo Y, Zhang S, Zhou L. Acetylacetone effectively controlled the secondary metabolites of Microcystis aeruginosa under simulated sunlight irradiation. J Environ Sci (China) 2024; 135:285-295. [PMID: 37778804 DOI: 10.1016/j.jes.2022.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 12/02/2022] [Accepted: 12/03/2022] [Indexed: 10/03/2023]
Abstract
Inactivation of cyanobacterial cells and simultaneous control of secondary metabolites is of significant necessity for the treatment of cyanobacteria-laden water. Acetylacetone (AcAc) has been reported a specific algicide to inactivate Microcystis aeruginosa (M. aeruginosa) and an effective light activator to degrade pollutants. This study systematically investigated the photodegradation ability of AcAc under xenon (Xe) irradiation on the secondary metabolites of M. aeruginosa, mainly algal organic matter (AOM), especially toxic microcystin-LR (MC-LR). Results showed that AcAc outperformed H2O2 in destructing the protein-like substances, humic acid-like matters, aromatic proteins and fulvic-like substances of AOM. For MC-LR (250 µg/L), 0.05 mmol/L AcAc attained the same degradation efficiency (87.0%) as 0.1 mmol/L H2O2. The degradation mechanism of Xe/AcAc might involve photo-induced energy/electron transfer and formation of carbon center radicals. Alkaline conditions (pH > 9.0) were detrimental to the photoactivity of AcAc, corresponding to the observed degradation rate constant (k1 value) of MC-LR drastically decreasing to 0.0013 min-1 as solution pH exceeded 9.0. The PO43- and HCO3- ions had obvious inhibition effects, whereas NO3- slightly improved k1 value from 0.0277 min-1 to 0.0321 min-1. The presence of AOM did not significantly inhibit MC-LR degradation in Xe/AcAc system. In addition, the biological toxicity of MC-LR was greatly reduced after photoreaction. These results demonstrated that AcAc was an alternative algicidal agent to effectively inactivate algal cells and simultaneously control the secondary metabolites after cell lysis. Nevertheless, the concentration and irradiation conditions should be further optimized in practical application.
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Affiliation(s)
- Xiaomeng Wang
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
| | - Yixin Luo
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Shujuan Zhang
- The State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Lixiang Zhou
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
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3
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Huang X, Yang G. Enhanced immobilization of Arsenic(III) and Auto-oxidation to Arsenic(V) by titanium oxide (TiO 2), due to Single-Atom vacancies and oxyanion formation. J Colloid Interface Sci 2023; 650:1327-1338. [PMID: 37478750 DOI: 10.1016/j.jcis.2023.07.103] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/28/2023] [Accepted: 07/16/2023] [Indexed: 07/23/2023]
Abstract
Pollution control of As(III), a naturally occurring carcinogen, has recently gained a global attention, while due to the dominance of neutral H3AsO3 over a wide pH range, As(III) immobilization by most minerals is not efficient as As(V) immobilization. TiO2 shows promise for controlling As(III) pollution, and herein, a comprehensive study about As(III) adsorption by TiO2 and oxyanion formation is conducted by means of DFT + D3 methods. Both anatase and rutile are effective for As(III) adsorption, while As(III) adsorption affinities differ significantly and are -1.48 and -3.79 eV for pristine surfaces, ascend to -3.85 and -5.08 eV for O vacancies, and further to -5.37 and -5.26 eV for Ti vacancies, respectively. The bidentate binuclear complexes dominate for pristine surfaces, and O vacancies prefer OAs insertion into TiO2 lattice, while for Ti vacancies, all As(III) centers are auto-oxidized to As(V). Ti-3d, O-2p or/and As-4p rather than other orbitals contribute significantly to As adsorption, and O and Ti vacancies promote adsorption through stronger orbital hybridization. The superior adsorption for Ti vacancies originates from As(V) formation instead of bonding interactions. The formation of As oxyanions, which may occur spontaneously at pristine surfaces and is greatly promoted by O and Ti vacancies, enhances As(III) adsorption pronouncedly and becomes a viable strategy for As(III) immobilization. H2AsO3- and HAsO32- dominate for pristine surfaces and O vacancies, and for Ti vacancies, H2AsO4- and HAsO42- dominate over anatase whereas AsO43- also makes an important contribution over rutile. Results rationalize experimental observations available, and provide significantly new insights about the migration, bioavailability and fate of As(III) over TiO2 surfaces that facilitate the exploration of scavengers for As and other pollutants.
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Affiliation(s)
- Xiaoxiao Huang
- College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Gang Yang
- College of Resources and Environment, Southwest University, Chongqing 400715, China.
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4
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Zhang C, Zhang G, Jin J, Zheng H, Zhou Z, Zhang S. Selenite-Catalyzed Reaction between Benzoquinone and Acetylacetone Deciphered the Enhanced Inhibition on Microcystis aeruginosa Growth. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6188-6195. [PMID: 37011377 DOI: 10.1021/acs.est.2c09682] [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: 06/19/2023]
Abstract
The coexistence of selenite (Se(IV)) and acetylacetone (AA) generated a synergistic effect on the growth inhibition of a bloom-forming cyanobacterium, Microcystis aeruginosa. The mechanism behind this phenomenon is of great significance in the control of harmful algal blooms. To elucidate the role of Se(IV) in this effect, the reactions in ternary solutions composed of Se(IV), AA (or two other similar hydrogen donors), and quinones, especially benzoquinone (BQ), were investigated. The transformation kinetic results demonstrate that Se(IV) played a catalytic role in the reactions between AA (or ascorbic acid) and quinones. By comparison with five other oxyanions (sulfite, sulfate, nitrite, nitrate, and phosphate) and two AA derivatives, the formation of an AA-Se(IV) complexation intermediate was confirmed as a key step in the accelerated reactions between BQ and AA. To our knowledge, this is the first report on Se(IV) as a catalyst for quinone-involved reactions. Since both quinones and Se are essential in cells and there are many other chemicals of similar electron-donating properties to that of AA, the finding here shed light on the regulation of electron transport chains in a variety of processes, especially the redox balances that are tuned by quinones and glutathione.
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Affiliation(s)
- Chengyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Guoyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Jiyuan Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Hongcen Zheng
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Zhiwei Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
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Wei S, Zhou C, Zhang G, Zheng H, Chen Z, Zhang S. Effects of a redox-active diketone on the photochemical transformation of roxarsone: Mechanisms and environmental implications. CHEMOSPHERE 2022; 308:136326. [PMID: 36084835 DOI: 10.1016/j.chemosphere.2022.136326] [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: 07/13/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 06/15/2023]
Abstract
Organoarsenical antibiotics pose a severe threat to the environment and human health. In aquatic environment, dissolved organic matter (DOM)-mediated photochemical transformation is one of the main processes in the fate of organoarsenics. Dicarbonyl is a typical redox-active moiety in DOM. However, the knowledge on the photoconversion of organoarsenics by DOM, especially the contributions of dicarbonyl moieties is still limited. Here, we systematically investigated the photochemical transformation of three organoarsenics with the simplest β-diketone, acetylacetone (AcAc), as a model dicarbonyl moiety of DOM. The presence of AcAc significantly enhanced the photochemical conversion of roxarsone (ROX), whereas only minor effects were observed for 3-amino-4-hydroxyphenylarsonic acid (HAPA) and arsanilic acid (ASA), because the latter two (with an amino (-NH2) group) are more photoactive than ROX (with a nitro (-NO2) group). The results demonstrate that AcAc was a potent photo-activator and the reduction of -NO2 to -NH2 might be a rate-limiting step in the phototransformation of ROX. At a 1:1 M ratio of AcAc to ROX, the photochemical transformation rate of ROX was increased by 7 folds. In O2-rich environment, singlet oxygen, peroxide radicals, and ·OH were the main reactive species that led to the breakage of the C-As bond in ROX and the oxidation of the released arsono group to arsenate, whereas the triplet-excited state of AcAc (3AcAc*) and carbon-centered radicals from the photolysis of AcAc dominated in the reductive transformation of ROX. In anoxic environment, 3-amino-4-hydroxyphenylarsonic acid was one of the main reductive transformation intermediates of ROX, whose photolysis rate was about 35 times that of ROX. The knowledge obtained here is of great significance to better understand the fate of organoarsenics in natural environment.
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Affiliation(s)
- Shuangshuang Wei
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Chang Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Guoyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Hongcen Zheng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Zhihao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
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Wang YN, Wang SD, Lu SQ, Wang F, Zou GD, Liu HQ, Cao KZ, Dong PH, Dou WQ. A dual fluorescent sensor coordination polymer for efficient recognition of acetylacetone and Cr(VI) anions. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2021.120666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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7
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Houska J, Salhi E, Walpen N, von Gunten U. Oxidant-reactive carbonous moieties in dissolved organic matter: Selective quantification by oxidative titration using chlorine dioxide and ozone. WATER RESEARCH 2021; 207:117790. [PMID: 34740166 DOI: 10.1016/j.watres.2021.117790] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 06/13/2023]
Abstract
The application of oxidants for disinfection or micropollutant abatement during drinking water and wastewater treatment is accompanied by oxidation of matrix components such as dissolved organic matter (DOM). To improve predictions of the efficiency of oxidation processes and the formation of oxidation products, methods to determine concentrations of oxidant-reactive phenolic, olefinic or amine-type DOM moieties are critical. Here, a novel selective oxidative titration approach is presented, which is based on reaction kinetics of oxidation reactions towards certain DOM moieties. Phenolic moieties were determined by oxidative titration with ClO2 and O3 for five DOM isolates and two secondary wastewater effluent samples. The determined concentrations of phenolic moieties correlated with the electron-donating capacity (EDC) and the formation of inorganic ClO2-byproducts (HOCl, ClO2-, ClO3-). ClO2-byproduct yields from phenol and DOM isolates and changes due to the application of molecular tagging for phenols revealed a better understanding of oxidant-reactive structures within DOM. Overall, oxidative titrations with ClO2 and O3 provide a novel and promising tool to quantify oxidant-reactive moieties in complex mixtures such as DOM and can be expanded to other matrices or oxidants.
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Affiliation(s)
- Joanna Houska
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Elisabeth Salhi
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Switzerland
| | - Nicolas Walpen
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Switzerland
| | - Urs von Gunten
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, 8092 Zurich, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
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8
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Chen M, Chen Z, Wu P, Chen JP. Simultaneous oxidation and removal of arsenite by Fe(III)/CaO 2 Fenton-like technology. WATER RESEARCH 2021; 201:117312. [PMID: 34146764 DOI: 10.1016/j.watres.2021.117312] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 04/26/2021] [Accepted: 05/25/2021] [Indexed: 06/12/2023]
Abstract
Arsenite contaminated water is one of severe global environmental problems. It is challenging to treat As(III) pollution by a one-step technology. In this study, we developed a Fe(III)/CaO2 Fenton-like technology for the treatment of As(III). The simultaneous oxidation of arsenite and removal of arsenic were achieved with efficiencies of nearly 100% and 95.8% respectively, which outperforms conventional technologies. It worked well in pH 3 to 9, and in the presence of cationic heavy metals, anions and humic acid. Moreover, the PO43- inhibited the removal of As(III). •OH and 1O2 played the important roles in the oxidation of As(III). The Ca(II) derived from CaO2 made a significant contribution to the oxidation and removal of As(III). The SEM and XPS studies confirmed that the formation of Ca-Fe nascent colloid caused the effective removal of arsenic. Our study demonstrates that the one-step Fe(III)/CaO2 technology has a great potential for purification of the As(III)-contaminated water.
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Affiliation(s)
- Meiqing Chen
- Department of Civil and Environmental Engineering, National University of Singapore, Kent Ridge Crescent, Singapore 119260, Singapore; NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore 117411, Singapore; School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Zhihao Chen
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore 117411, Singapore
| | - Pingxiao Wu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
| | - J Paul Chen
- Department of Civil and Environmental Engineering, National University of Singapore, Kent Ridge Crescent, Singapore 119260, Singapore; NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore 117411, Singapore.
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9
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Yang F, Sheng B, Wang Z, Xue Y, Liu J, Ma T, Bush R, Kušić H, Zhou Y. Performance of UV/acetylacetone process for saline dye wastewater treatment: Kinetics and mechanism. JOURNAL OF HAZARDOUS MATERIALS 2021; 406:124774. [PMID: 33310333 DOI: 10.1016/j.jhazmat.2020.124774] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 06/12/2023]
Abstract
Futility of traditional advanced oxidation processes (AOPs) in saline wastewater treatment has stimulated the quest for novel "halotolerant" chemical oxidation technology. Acetylacetone (AA) has proven to be a potent photo-activator in the degradation of dyes, but the applicability of UV/AA for saline wastewater treatment needs to be verified. In this study, degradation of crystal violet (CV) was investigated in the UV/AA system in the presence of various concentrations of exogenic Cl- or Br-. The results reveal that degradation, mineralization and even accumulation of adsorbable organic halides (AOX) were not significantly affected by the addition of Cl- or Br-. Rates of CV degradation were enhanced by elevating either AA dosage or solution acidity. An apparent kinetic rate equation was developed as r = -d[CV]/dt = k[CV]a[AA]b = (7.34 × 10-4 mM1-(a+b) min-1) × [CV]a=0.16 [AA]b=0.97. In terms of results of radical quenching experiments, direct electron/energy transfer is considered as the major reaction mechanism, while either singlet oxygen or triplet state (3(AA)*) might be involved. Based on identification of degradation byproducts, a possible degradation pathway of CV in the UV/AA system is proposed.
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Affiliation(s)
- Fei Yang
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China; School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Bo Sheng
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China
| | - Zhaohui Wang
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China; Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N. Zhongshan Road, Shanghai 200062, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, China.
| | - Ying Xue
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China; School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Jianshe Liu
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Tianyi Ma
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Richard Bush
- Sustainable Development Institute, Monash University, Melbourne, Victoria 3800, Australia
| | - Hrvoje Kušić
- Faculty of Chemical Engineering and Technology, University of Zagreb, 10000 Zagreb, Croatia
| | - Yanbo Zhou
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, China; State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China
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Synthesis, characterization of iron-doped TiO2(B) nanoribbons for the adsorption of As(III) from drinking water and evaluating the performance from the perspective of physical chemistry. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114556] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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11
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Wu B, Zhang L, Wei S, Ou'Yang L, Yin R, Zhang S. Reduction of chromate with UV/diacetyl for the final effluent to be below the discharge limit. JOURNAL OF HAZARDOUS MATERIALS 2020; 389:121841. [PMID: 31848094 DOI: 10.1016/j.jhazmat.2019.121841] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 12/05/2019] [Accepted: 12/05/2019] [Indexed: 06/10/2023]
Abstract
Reduction of Cr(VI) to Cr(III) is helpful to lower the toxicity risk and also necessary for the removal of chromium from waste streams through alkaline precipitation. We compared the reduction of Cr(VI) in six UV systems with oxalic acid (OA), ethylenediaminetetraacetic acid (EDTA), salicylic acid (SA), hydroquinone (HQ), acetylacetone (AA) and diacetyl (BD) as chelating or non-chelating photo-activators. Overall, HQ, AA and BD were much more efficient than the carboxylic acids for the photo-reduction of Cr(VI). By introduction of UV to HQ system, the pseudo-first-order rate constant of Cr(VI) reduction at pH 5.1 was increased about 50 times. However, due to the formation of colloidal polymers, the UV/HQ treated solutions were dark in color and had a high turbidity (82 NTU). The effects of AA and BD on the photoreduction of Cr(VI) were similar. The UV/BD treated solution was colorless and clear with a turbidity lower than 1 NTU and a residual Cr less than 0.1 mg/L. The results demonstrate that UV/BD is a promising approach for the treatment of Cr(VI)-laden wastewater. The findings here also suggest that utilization of diketones in redox conversion of contaminants is a topic deserving further research.
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Affiliation(s)
- Bingdang Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Li Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Shijie Wei
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Lixue Ou'Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Ran Yin
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
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Sarkar A, Paul B. Evaluation of the performance of zirconia-multiwalled carbon nanotube nanoheterostructures in adsorbing As(III) from potable water from the perspective of physical chemistry and chemical physics with a special emphasis on approximate site energy distribution. CHEMOSPHERE 2020; 242:125234. [PMID: 31896174 DOI: 10.1016/j.chemosphere.2019.125234] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/21/2019] [Accepted: 10/25/2019] [Indexed: 06/10/2023]
Abstract
In this study, the performance of zirconia-multiwalled carbon-nanotube nanoheterostructure in adsorbing the highly toxic water-contaminant As(III) from water has been probed from the perspective of physical chemistry and chemical physics. The adsorbent found extremely efficient in adsorbing As(III) from potable water. Moreover, its ability to oxidize As(III) to As(V) in the aqueous solution has been evinced by the XPS studies. The values of the maximum adsorption capacities (qm) depend on the isotherm studied and in this study, no wonder different values of qm are obtained for different adsorption isotherms. The thermodynamic studies advocate the exothermic and spontaneous nature of the adsorption process. Calculation on density functional theory (DFT) also suggested the exothermic nature of the adsorption process. DFT calculation further revealed the role of the Zr-O and Zr-OH bridges in binding As(III) species on the zirconia surface. However, this study finds an adverse effect of visible light-irradiation on the adsorption process. Furthermore, this study propounds an approach to estimate the maximum solubility of As(III) in water combining the Cerofolini's condensation-approximation and Polanyi adsorption potential. Detailed analysis on the approximate adsorption site energy distribution (f(E*)) further finds an inconsistency in the formula used to estimate qm using f(E*), which underestimates qm. The inconsistency, for the very first time, has successfully been resolved by modifying the heterogeneity related parameter in f(E*).
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Affiliation(s)
- Arpan Sarkar
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, 826004, India.
| | - Biswajit Paul
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, 826004, India.
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Zhang L, Wu B, Gan Y, Chen Z, Zhang S. Sludge reduction and cost saving in removal of Cu(II)-EDTA from electroplating wastewater by introducing a low dose of acetylacetone into the Fe(III)/UV/NaOH process. JOURNAL OF HAZARDOUS MATERIALS 2020; 382:121107. [PMID: 31493742 DOI: 10.1016/j.jhazmat.2019.121107] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 08/21/2019] [Accepted: 08/26/2019] [Indexed: 06/10/2023]
Abstract
Cu(II)-EDTA is highly stable in a wide pH range (3.0∼12.0) and hard to be removed by the conventional precipitation method. Fe(III) displacement/UV photolysis/alkaline precipitation [Fe(III)/UV/NaOH] has been proposed as a promising method for the removal of Cu(II)-EDTA. Nevertheless, a high dose of Fe(III) is needed in this combined process, resulting in the production of a large amount of hazardous sludge. The photochemistry of Fe(III) is known to be ligand-dependent. Fe(III)-oxalate complexes are strongly photoactive. However, the addition of oxalic acid to the Fe(III)/UV/NaOH process was of little help. Acetylacetone (AA) is a good chelating ligand for many metals and has been proved as an efficient photo-activator. By introducing a low dose of AA ([AA]/[Cu] = 1.5) into the Fe(III)/UV/NaOH process, the Fe(III) dosage ([Fe]/[Cu]) was reduced from 10.4 to 3.2. As a result, the chemical cost was reduced from 13.9 to 7.6 kW h/m3. Meanwhile, the energy cost in the UV photolysis was reduced from 1066.5 to 752.4 kW h/m3. Most importantly, the sludge yields were reduced from 8.3 to 2.7 kg/m3 in a simulated wastewater and from 101.8 to 30.8 kg/m3 in a real electroplating wastewater. Such a sludge reduction is of great significance in mitigating the load of landfill.
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Affiliation(s)
- Li Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Bingdang Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Yonghai Gan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Zhihao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
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14
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Ren D, Ren Z, Chen F, Wang B, Huang B. Predictive role of spectral slope ratio towards 17α-ethynylestradiol photodegradation sensitized by humic acids. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 254:112959. [PMID: 31377327 DOI: 10.1016/j.envpol.2019.112959] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/23/2019] [Accepted: 07/24/2019] [Indexed: 06/10/2023]
Abstract
Humic acids (HAs) have been shown to dominate the photodegradation of steroid estrogens in natural waters. Nevertheless, how the photosensitizing ability of HAs relates to their structural and optical characteristics remains largely unknown. In this study, 17α-ethynylestradiol (EE2) was selected as a model compound to study to what extent easily-measurable characteristics of HAs might be used to predict their photosensitization potency. HAs were extracted from sediments of two different sources, and then subjected to structural and optical properties characterization using elemental analyzer, UV-vis spectroscopy and fluorescence spectroscopy. Photochemical experiments show that the HAs from the two sources can effectively meditate EE2 photodegradation. Although with drastically different structural and optical properties, the photosensitizing ability of these HAs towards EE2 can be well described by simple linear regressions using a spectroscopic index, the spectral slope ratio (SR). This optical indicator is correlated with various physicochemical properties of HAs, including the molecular weight, lignin content, charge-transfer interaction potential, photobleaching extent and sources. No universal prediction model could be established for predicting EE2 photodegradation kinetics on the basis of SR, but in specific waters SR could be a powerful indictor for predicting the EE2 photodegradation sensitized by HAs.
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Affiliation(s)
- Dong Ren
- College of Environmental Science and Engineering, China West Normal University, Nanchong, 637009, China
| | - Zhaogang Ren
- College of Environmental Science and Engineering, China West Normal University, Nanchong, 637009, China
| | - Fang Chen
- College of Environmental Science and Engineering, China West Normal University, Nanchong, 637009, China
| | - Bin Wang
- School of Environment and Resource, Southwest University of Science and Technology, Mianyang, 621010, China
| | - Bin Huang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, China.
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15
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Jin J, Zhang S, Wu B, Chen Z, Zhang G, Tratnyek PG. Enhanced Photooxidation of Hydroquinone by Acetylacetone, a Novel Photosensitizer and Electron Shuttle. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:11232-11239. [PMID: 31469553 DOI: 10.1021/acs.est.9b02751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Quinones are important electron shuttles as well as micropollutants in the nature. Acetylacetone (AA) is a newly recognized electron shuttle in aqueous media exposed to UV irradiation. Herein, we studied the interactions between AA and hydroquinone (QH2) under steady-state and transient photochemical conditions to clarify the possible reactions and consequences if QH2 and AA coexist in a solution. Steady-state experimental results demonstrate that the interactions between AA and QH2 were strongly affected by dissolved oxygen. In O2-rich solutions, the phototransformation of QH2 was AA-independent. Both QH2 and AA utilize O2 as the electron acceptor, but in O2-insufficient solutions, AA became an important electron acceptor for the oxidation of QH2. In all cases, the coexistence of AA increased the phototransformation of QH2, whereas the decomposition of AA in O2-saturated and oversaturated solutions was inhibited by the presence of QH2. The underlying mechanisms were investigated by a combination of laser flash photolysis (LFP) and reduction potential analysis. The LFP results show that the excited AA serves as a better electron shuttle than QH2. As a consequence, AA might regulate the redox cycling of quinones, leading to significant effects on many processes, ranging from photosynthesis and respiration to photodegradation.
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Affiliation(s)
- Jiyuan Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Bingdang Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Zhihao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Guoyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Paul G Tratnyek
- OHSU-PSU School of Public Health , Oregon Health & Science University , 3181 SW Sam Jackson Park Road , Portland 97239 , Oregon , United States
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16
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Jin J, Chen Z, Song X, Wu B, Zhang G, Zhang S. Effects of acetylacetone on the thermal and photochemical conversion of benzoquinone in aqueous solution. CHEMOSPHERE 2019; 223:628-635. [PMID: 30798058 DOI: 10.1016/j.chemosphere.2019.02.080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/08/2019] [Accepted: 02/13/2019] [Indexed: 06/09/2023]
Abstract
Quinones are components of electron transport chains in photosynthesis and respiration. Acetylacetone (AA), structurally similar to benzoquinone (BQ) for the presence of two identical carbonyl groups, has been reported as a quinone-like electron shuttle. Both BQ and AA are important chemicals in the aquatic environment. However, little information is known about their interactions if co-existed. We found here that AA significantly enhanced the conversion of BQ. By analyzing the evolution of chemical concentration, solution pH, dissolved oxygen, and the final products, the interactions between AA and BQ were elucidated. The reactions between BQ and AA generated oxygen but ultimately led to the reduction of solution pH and dissolved oxygen. The reactions proceeded faster under indoor lighting condition than in the dark. The formation of semiquinone radicals is believed as the primary step. The secondary AA-derived radicals might be strongly oxidative or reductive, depending on the concentration of dissolved oxygen. Insoluble humus was generated in the mixture of BQ and AA. These results suggest that the presence of AA might interfere with photosynthesis and respiration through the interactions with quinones.
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Affiliation(s)
- Jiyuan Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Zhihao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Xiaojie Song
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Bingdang Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Guoyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
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17
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Chen Z, Jin J, Song X, Zhang G, Zhang S. Redox Conversion of Arsenite and Nitrate in the UV/Quinone Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:10011-10018. [PMID: 30063337 DOI: 10.1021/acs.est.8b03538] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Whether superoxide radical anion (O2•-) was a key reactive species in the oxidation of arsenite (As(III)) in photochemical processes has long been a controversial issue. With hydroquinone (BQH2) and 1,4-benzoquinone (BQ) as redox mediators, the photochemical oxidation of As(III) and reduction of nitrate (NO3-) was carefully investigated. O2•-, singlet oxygen (1O2), H2O2, and semiquinone radical (BQH•) were all possible reactive species in the irradiated system. However, since the formation of As(IV) is a necessary step in the oxidation of As(III), taking the standard reduction potentials into account, the reactions between the above species and As(III) were thermodynamically unfavorable. On the basis of radical scavenging experiments, hydroxyl radical (•OH) was proved as the key species that led to the oxidation of As(III) in the UV/BQH2 system. It should be noted that the •OH radicals were generated from the photolysis of H2O2, which came from the disproportionation of O2•- and the reaction of O2•- with BQH2. Both the photoejected eaq- from 1(BQH2)* and the direct electron transfer with 3(BQH2)* contributed to the reduction of NO3- in the UV/BQH2 process. No synergistic effect was observed in the redox conversion of As(III) and NO3-, further demonstrating that the role of BQH• was negligible in the studied systems. The results here are helpful for a better understanding of the photochemical behaviors of quinones in the aquatic environment.
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Affiliation(s)
- Zhihao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , 163 Xianlin Avenue , Nanjing , 210023 , China
| | - Jiyuan Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , 163 Xianlin Avenue , Nanjing , 210023 , China
| | - Xiaojie Song
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , 163 Xianlin Avenue , Nanjing , 210023 , China
| | - Guoyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , 163 Xianlin Avenue , Nanjing , 210023 , China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , 163 Xianlin Avenue , Nanjing , 210023 , China
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18
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Sarkar A, Sarkar A, Paul B, Khan GG. Fabrication of One Dimensional MnO
2
‐TiO
2
Nano‐Heterostructures for Enhanced Hole Mediated Oxidation of As(III) in Potable Water. ChemCatChem 2018. [DOI: 10.1002/cctc.201800915] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Arpan Sarkar
- Department of Environmental Science and EngineeringIndian Institute of Technology (Indian School of Mines) Dhanbad Jharkhand 826 004 India
| | - Ayan Sarkar
- Centre for Research in Nanoscience and NanotechnologyUniversity of Calcutta Salt Lake, Sector-III, Block -JD2 Kolkata 700 106 India
| | - Biswajit Paul
- Department of Environmental Science and EngineeringIndian Institute of Technology (Indian School of Mines) Dhanbad Jharkhand 826 004 India
| | - Gobinda Gopal Khan
- Department of Material Science and EngineeringTripura University (A Central University) Tripura 799 022 India
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