1
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Warias JE, Petersdorf L, Hövelmann SC, Giri RP, Lemke C, Festersen S, Greve M, Mandin P, LeBideau D, Bertram F, Magnussen OM, Murphy BM. The laser pump X-ray probe system at LISA P08 PETRA III. JOURNAL OF SYNCHROTRON RADIATION 2024; 31:779-790. [PMID: 38843001 PMCID: PMC11226150 DOI: 10.1107/s1600577524003400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 04/17/2024] [Indexed: 07/06/2024]
Abstract
Understanding and controlling the structure and function of liquid interfaces is a constant challenge in biology, nanoscience and nanotechnology, with applications ranging from molecular electronics to controlled drug release. X-ray reflectivity and grazing incidence diffraction provide invaluable probes for studying the atomic scale structure at liquid-air interfaces. The new time-resolved laser system at the LISA liquid diffractometer situated at beamline P08 at the PETRA III synchrotron radiation source in Hamburg provides a laser pump with X-ray probe. The femtosecond laser combined with the LISA diffractometer allows unique opportunities to investigate photo-induced structural changes at liquid interfaces on the pico- and nanosecond time scales with pump-probe techniques. A time resolution of 38 ps has been achieved and verified with Bi. First experiments include laser-induced effects on salt solutions and liquid mercury surfaces with static and varied time scales measurements showing the proof of concept for investigations at liquid surfaces.
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Affiliation(s)
- Jonas Erik Warias
- Institute of Experimental and Applied PhysicsKiel UniversityLeibnizstrasse 1924118KielGermany
| | - Lukas Petersdorf
- Institute of Experimental and Applied PhysicsKiel UniversityLeibnizstrasse 1924118KielGermany
- Ruprecht-Haensel Laboratory, Olshausenstrasse 40, 24098Kiel, Germany
| | - Svenja Carolin Hövelmann
- Institute of Experimental and Applied PhysicsKiel UniversityLeibnizstrasse 1924118KielGermany
- Ruprecht-Haensel Laboratory, Olshausenstrasse 40, 24098Kiel, Germany
- Deutsches Elektronen-Synchrotron DESYNotkestrasse 8522607HamburgGermany
| | - Rajendra Prasad Giri
- Institute of Experimental and Applied PhysicsKiel UniversityLeibnizstrasse 1924118KielGermany
| | - Christoph Lemke
- Institute of Experimental and Applied PhysicsKiel UniversityLeibnizstrasse 1924118KielGermany
| | - Sven Festersen
- Institute of Experimental and Applied PhysicsKiel UniversityLeibnizstrasse 1924118KielGermany
| | - Matthias Greve
- Institute of Experimental and Applied PhysicsKiel UniversityLeibnizstrasse 1924118KielGermany
| | | | | | - Florian Bertram
- Deutsches Elektronen-Synchrotron DESYNotkestrasse 8522607HamburgGermany
| | - Olaf Magnus Magnussen
- Institute of Experimental and Applied PhysicsKiel UniversityLeibnizstrasse 1924118KielGermany
- Ruprecht-Haensel Laboratory, Olshausenstrasse 40, 24098Kiel, Germany
| | - Bridget Mary Murphy
- Institute of Experimental and Applied PhysicsKiel UniversityLeibnizstrasse 1924118KielGermany
- Ruprecht-Haensel Laboratory, Olshausenstrasse 40, 24098Kiel, Germany
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2
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Zhai Z, Zhang C, Chu L, Zhao Y, Zhou X, Zhang Y. Effective defluorination of novel hexafluoropropylene oxide oligomer acids under mild conditions by UV/sulfite/iodide: mechanisms and ecotoxicity. WATER RESEARCH 2024; 258:121804. [PMID: 38781621 DOI: 10.1016/j.watres.2024.121804] [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: 02/05/2024] [Revised: 04/08/2024] [Accepted: 05/18/2024] [Indexed: 05/25/2024]
Abstract
It has recently been discovered that HFPO-TA (a processing aid in the production of fluoropolymers) has high levels of bioaccumulation and biotoxicity. Hydrated electrons (eaq-) have been proposed to be potent nucleophiles that may decompose PFAS. Unlike previous studies in which the generation of eaq- was often restricted to anaerobic or highly alkaline environments, in this study, we applied the UV/SO32-/I- process under mild conditions of neutrality, low source chemical demand, and open-air, which achieved effective degradation (81.92 %, 0.834 h-1) and defluorination (48.99 %, 0.312 h-1) of HFPO-TA. With I- as the primary source of eaq-, SO32- acting as an I- regenerator and oxidizing substances scavenger, UV/SO32-/I- outperformed others under mild circumstances. The eaq- were identified as the main active species by quenching experiments and electron paramagnetic resonance (EPR). During degradation, the first site attacked by eaq- was the ether bond (C6-O7), followed by the generation of HFPO-DA, TFA, acetic and formic acid. Degradation studies of other HFPOs have shown that the defluorination of HFPOs was accompanied by a clear chain-length correlation. At last, toxicological experiments confirmed the safety of the process. This study updated our understanding of the degradation of newly PFASs and the application of eaq- mediated photoreductive approaches under mild conditions.
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Affiliation(s)
- Zhenyu Zhai
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Chaojie Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
| | - Liquan Chu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Yunmeng Zhao
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Xuefei Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Yalei Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
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3
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Amador CK, Vyas S, Strathmann TJ. Kinetic Model for Predicting Perfluoroalkyl Acid Degradation During UV-Sulfite Treatment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:6425-6434. [PMID: 38554136 DOI: 10.1021/acs.est.3c10584] [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: 04/01/2024]
Abstract
Hydrated electron (eaq-) treatment processes show great potential in remediating recalcitrant water contaminants, including perfluoroalkyl and polyfluoroalkyl substances (PFAS). However, treatment efficacy depends upon many factors relating to source water composition, UV light source characteristics, and contaminant reactivity. Here, we provide critical insights into the complex roles of solution parameters on contaminant abatement through application of a UV-sulfite kinetic model that incorporates first-principles information on eaq- photogeneration and reactivity. The model accurately predicts decay profiles of short-chain perfluoroalkyl acids (PFAAs) during UV-sulfite treatment and facilitates quantitative interpretation of the effects of changing solution composition on PFAS degradation rates. Model results also confirm that the enhanced degradation of PFAAs observed under highly alkaline pH conditions results from changes in speciation of nontarget eaq- scavengers. Reverse application of the model to UV-sulfite data collected for longer chain PFAAs enabled estimation of bimolecular rate constants (k2, M-1 s-1), providing an alternative to laser flash photolysis (LFP) measurements that are not feasible due to the water solubility limitations of these compounds. The proposed model links the disparate means of investigating eaq- processes, namely, UV photolysis and LFP, and provides a framework to estimate UV-sulfite treatment efficacy of PFAS in diverse water sources.
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Affiliation(s)
- Camille K Amador
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Shubham Vyas
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Timothy J Strathmann
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
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4
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Zhou M, You T, Yan Z, Zhu X, Pi M, Zeng X, Wang S, Jia Y. Iodide and sulfite synergistically accelerate the photo-reduction and recovery of As(V) and As(III) in sulfite/iodide/UV process: Efficiency and mechanism. WATER RESEARCH 2024; 252:121210. [PMID: 38324984 DOI: 10.1016/j.watres.2024.121210] [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: 11/29/2023] [Revised: 01/04/2024] [Accepted: 01/26/2024] [Indexed: 02/09/2024]
Abstract
Photo-reduction of arsenic (As) by hydrated electron (eaq-) and recovery of elemental arsenic (As(0)) is a promising pathway to treat As-bearing wastewater. However, previously reported sulfite/UV system needs large amounts of sulfite as the source of eaq-. This work suggests a sulfite/iodide/UV approach that is more efficient and consumes much less chemical reagents to remove As(III) and As(V) and recover valuable As(0) from wastewater, hence preventing the production of large amounts of As-containing hazardous wastes. Our results showed that more than 99.9% of As in the aqueous phase was reduced to highly pure solid As(0) (>99.5 wt%) by sulfite/iodide/UV process under alkaline conditions. Sulfite and iodide worked synergistically to enhance reductive removal of As. Compared with sulfite/UV, the addition of iodide had a substantially greater effect on As(III) (over 200 times) and As(V) (approximately 30 times) removals because of its higher absorptivity and quantum yield of eaq-. Furthermore, more than 90% of the sulfite consumption was decreased by adding a small amount of iodide while maintaining similar reduction efficiency. Hydrated electron (eaq-) was mainly responsible for As(III) and As(V) reductions and removals under alkaline conditions, while both SO3•- and reactive iodine species (e.g., I•, I2, I2•-, and I3-) may oxidize As(0) to As(III) or As(V). Acidic circumstances caused sulfite protonation and the scavenging of eaq- by competing processes. Dissolved oxygen (O2) and CO32- prevented As reduction by light blocking or eaq- scavenging actions, but Cl-, Ca2+, and Mg2+ showed negligible impacts. This study presented an efficient method for removing and recovering As from wastewater.
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Affiliation(s)
- Mengchao Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Tingting You
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Zelong Yan
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Xiayu Zhu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Minhan Pi
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Xiangfeng Zeng
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Shaofeng Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
| | - Yongfeng Jia
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
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5
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Xie R, Lei D, Xie X, Suo Z, Leung DYC, Cao J, Ruimei F, Huang H. Accelerated oxidation of VOCs via vacuum ultraviolet photolysis coupled with wet scrubbing process. J Environ Sci (China) 2023; 134:55-64. [PMID: 37673533 DOI: 10.1016/j.jes.2022.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 04/17/2022] [Accepted: 05/01/2022] [Indexed: 09/08/2023]
Abstract
Vacuum ultraviolet (VUV) photolysis is a facile method for volatile organic compounds (VOCs) elimination, but is greatly limited by the relatively low removal efficiency and the possible secondary pollution. To overcome above drawbacks, we developed an efficient method for VOCs elimination via VUV photolysis coupled with wet scrubbing process. In this coupled process, volatile toluene, a representative of VOCs, was oxidized by the gas-phase VUV photolysis, and then scrubbed into water for further oxidation by the liquid-phase VUV photolysis. More than 96% of toluene was efficiently removed by this coupled process, which was 2 times higher than that in the gas-phase VUV photolysis. This improvement was attributed to the synergistic effect between gas-phase and liquid-phase VUV photolysis. O3 and HO• are the predomination reactive species for the toluene degradation in this coupled process, and the generation of O3 in gas-phase VUV photolysis can efficiently enhance the HO• production in liquid-phase VUV photolysis. The result from in-situ proton transfer reaction ionization with mass analyzer (PTR-MS) further suggested that most intermediates were trapped by the wet scrubbing process and efficiently oxidized by the liquid-phase VUV photolysis, showing a high performance for controlling the secondary pollution. Furthermore, the result of stability test and the reuse of solution demonstrated that this coupled process has a highly stable and sustainable performance for toluene degradation. This study presents an environmentally benign and highly efficient VUV photolysis for gaseous VOCs removal in the wet scrubbing process.
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Affiliation(s)
- Ruijie Xie
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Dongxue Lei
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China; Scientific Research Academy of GuangXi Environmental Protection, Nanning 530022, China
| | - Xiaowen Xie
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Ziyi Suo
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Dennis Y C Leung
- Department of Mechanical Engineering, University of Hong Kong, Hong Kong 999077, China.
| | - Jianping Cao
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
| | - Fang Ruimei
- College of Environment and Resources, Chongqing Technology and Business University, Chongqing 400067, China
| | - Haibao Huang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
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6
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Hou C, Deng J, Li S, Li H, Zhou Y, Zhai Y. Differences between reductive defluorination of perfluorooctanoic acid by chlorination, bromination, and iodization in the vacuum-ultraviolet/sulfite process. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132459. [PMID: 37683349 DOI: 10.1016/j.jhazmat.2023.132459] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/25/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023]
Abstract
The introduction of iodide (I-) has broad perspectives on the decomposition of perfluorocarboxylates (PFCAs, CnF2n+1COO-). However, the iodinated substances produced are highly toxic synthetic chemicals, hence, it is urgent to find a similar alternative with less toxicity. In this work, the defluorination of perfluorooctanoic acid (PFOA) by I-, bromide (Br-) and chlorine (Cl-) was systematically compared in the VUV/sulfite process. Results indicated that the PFOA defluorination rates increased with increasing nucleophilicity of halogens (I > Br > Cl). Meanwhile, the introduction of I-, Br-, and Cl- reduced the interference of the coexisting water matrix on the degrading influence of PFOA. The in situ produced eaq-, SO3•-, H•, and HO• were recognized, among the addition of I- maximized the relative contribution of eaq- but Br- and Cl- decreased that of H• and other radicals. Additionally, HPLC/MS analysis revealed the presence of I-, Br-, and Cl- had a vital impact on the difference in product concentrations, while they had a negligible effect on the change in the pathway of degradation. Overall, this study demonstrated the similarities and differences between I-, Br-, and Cl-, which has significant implications for further understanding VUV/sulfite degradation.
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Affiliation(s)
- Changlan Hou
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Jiaqin Deng
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China
| | - Shanhong Li
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Hui Li
- Hunan Academy of Forestry and State Key Laboratory of Utilization of Woody Oil Resource, Changsha 410004, PR China
| | - Yin Zhou
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Yunbo Zhai
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
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7
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Wilsey MK, Taseska T, Meng Z, Yu W, Müller AM. Advanced electrocatalytic redox processes for environmental remediation of halogenated organic water pollutants. Chem Commun (Camb) 2023; 59:11895-11922. [PMID: 37740361 DOI: 10.1039/d3cc03176d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Halogenated organic compounds are widespread, and decades of heavy use have resulted in global bioaccumulation and contamination of the environment, including water sources. Here, we introduce the most common halogenated organic water pollutants, their classification by type of halogen (fluorine, chlorine, or bromine), important policies and regulations, main applications, and environmental and human health risks. Remediation techniques are outlined with particular emphasis on carbon-halogen bond strengths. Aqueous advanced redox processes are discussed, highlighting mechanistic details, including electrochemical oxidations and reductions of the water-oxygen system, and thermodynamic potentials, protonation states, and lifetimes of radicals and reactive oxygen species in aqueous electrolytes at different pH conditions. The state of the art of aqueous advanced redox processes for brominated, chlorinated, and fluorinated organic compounds is presented, along with reported mechanisms for aqueous destruction of select PFAS (per- and polyfluoroalkyl substances). Future research directions for aqueous electrocatalytic destruction of organohalogens are identified, emphasizing the crucial need for developing a quantitative mechanistic understanding of degradation pathways, the improvement of analytical detection methods for organohalogens and transient species during advanced redox processes, and the development of new catalysts and processes that are globally scalable.
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Affiliation(s)
- Madeleine K Wilsey
- Materials Science Program, University of Rochester, Rochester, New York 14627, USA.
| | - Teona Taseska
- Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - Ziyi Meng
- Materials Science Program, University of Rochester, Rochester, New York 14627, USA.
| | - Wanqing Yu
- Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - Astrid M Müller
- Materials Science Program, University of Rochester, Rochester, New York 14627, USA.
- Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, USA
- Department of Chemistry, University of Rochester, Rochester, New York 14627, USA
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8
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Li B, Pan H, Chen B. A review of factors affecting the formation and roles of primary and secondary reactive species in UV 254-based advanced treatment processes. WATER RESEARCH 2023; 244:120537. [PMID: 37683496 DOI: 10.1016/j.watres.2023.120537] [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: 04/06/2023] [Revised: 07/10/2023] [Accepted: 08/27/2023] [Indexed: 09/10/2023]
Abstract
The presence of organic micropollutants (OMPs) in water has been threatening human health and aquatic ecosystems worldwide. Ultraviolet-based advanced treatment processes (UV-ATPs) are one of the most effective and promising technologies to transform OMPs in water; therefore, an increasing number of emerging UV-ATPs are proposed. However, appropriate selection of UV-ATPs for practical applications is challenging because each UV-ATP generates different types and concentrations of reactive species (RSs) that may not be sufficient to degrade specific types of OMPs. Furthermore, the concentrations and types of RSs are highly influenced by anions and dissolved organic matter (DOM) coexisting in real waters, making systematic understandings of their interfering mechanisms difficult. To identify and address the knowledge gaps, this review provides a comparison of the generations and variations of various types of RSs in different UV-ATPs. These analyses not only prove the importance of water matrices on formation and consumption of primary and secondary RSs under different conditions, but also highlight the non-negligible roles of optical properties and reactivities of DOM and anions. For example, different UV-ATPs may be applicable to different target OMPs under different conditions; and the concentrations and roles of secondary RSs may outperform those of primary RSs in OMP degradation for real applications. With continuous progress and outstanding achievements in the UV-ATPs, it is hoped that the findings and conclusions of this review could facilitate further research and application of UV-ATPs.
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Affiliation(s)
- Boqiang Li
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen 518055, China
| | - Huimei Pan
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen 518055, China
| | - Baiyang Chen
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen 518055, China.
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9
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Lamas I, González J, Longarte A, Montero R. Influence of H-bonds on the photoionization of aromatic chromophores in water: The aniline molecule. J Chem Phys 2023; 158:2890456. [PMID: 37184001 DOI: 10.1063/5.0147503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/01/2023] [Indexed: 05/16/2023] Open
Abstract
We have conducted time-resolved experiments (pump-probe and pump-repump-probe) on a model aromatic chromophore, aniline, after excitation in water at 267 nm. In the initial spectra recorded, in addition to the absorption corresponding to the bright ππ* excitation, the fingerprint of a transient state with the electron located on the solvent molecule is identified. We postulate that the latter corresponds to the πσ* state along the N-H bond, whose complete relaxation with a ∼500 ps lifetime results in the formation of the fully solvated electron and cation. This ionization process occurs in parallel with the ππ* photophysical channel that yields the characteristic ∼1 ns fluorescence lifetime. The observed branched pathway is rationalized in terms of the different H-bonds that the water establishes with the amino group. The proposed mechanism could be common for aromatics in water containing N-H or O-H bonds and would allow the formation of separated charges after excitation at the threshold of their electronic absorptions.
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Affiliation(s)
- Iker Lamas
- Facultad de Ciencia y Tecnología, Departamento de Química Física, Universidad del País Vasco (UPV/EHU), Apart. 644, 48080 Bilbao, Spain
| | - Jorge González
- Facultad de Ciencia y Tecnología, Departamento de Química Física, Universidad del País Vasco (UPV/EHU), Apart. 644, 48080 Bilbao, Spain
| | - Asier Longarte
- Facultad de Ciencia y Tecnología, Departamento de Química Física, Universidad del País Vasco (UPV/EHU), Apart. 644, 48080 Bilbao, Spain
| | - Raúl Montero
- Facultad de Ciencia y Tecnología, SGIKER Laser Facility, UPV/EHU, Sarriena, S/N, 48940 Leioa, Spain
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10
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Reidelbach M, Bai M, Schneeberger M, Zöllner MS, Kubicek K, Kirchberg H, Bressler C, Thorwart M, Herrmann C. Solvent Dynamics of Aqueous Halides before and after Photoionization. J Phys Chem B 2023; 127:1399-1413. [PMID: 36728132 DOI: 10.1021/acs.jpcb.2c07992] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Electron transfer reactions can be strongly influenced by solvent dynamics. We study the photoionization of halides in water as a model system for such reactions. There are no internal nuclear degrees of freedom in the solute, allowing the dynamics of the solvent to be uniquely identified. We simulate the equilibrium solvent dynamics for Cl-, Br-, I-, and their respective neutral atoms in water, comparing quantum mechanical/molecular mechanical (QM/MM) and classical molecular dynamics (MD) methods. On the basis of the obtained configurations, we calculate the extended X-ray absorption fine structure (EXAFS) spectra rigorously based on the MD snapshots and compare them in detail with other theoretical and experimental results available in the literature. We find our EXAFS spectra based on QM/MM MD simulations in good agreement with their experimental counterparts for the ions. Classical MD simulations for the ions lead to EXAFS spectra that agree equally well with the experiment when it comes to the oscillatory period of the signal, even though they differ from the QM/MM radial distribution functions extracted from the MD. The amplitude is, however, considerably overestimated. This suggests that to judge the reliability of theoretical simulation methods or to elucidate fine details of the atomistic dynamics of the solvent based on EXAFS spectra, the amplitude as well as the oscillatory period need to be considered. If simulations fail qualitatively, as does the classical MD for the aqueous neutral halogen atoms, the resulting EXAFS will also be strongly affected in both oscillatory period and amplitude. The good reliability of QM/MM-based EXAFS simulations, together with clear qualitative differences in the EXAFS spectra found between halides and their atomic counterparts, suggests that a combined theory and experimental EXAFS approach is suitable for elucidating the nonequilibrium solvent dynamics in the photoionization of halides and possibly also for electron transfer reactions in more complex systems.
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Affiliation(s)
- Marco Reidelbach
- Department of Chemistry, Universität Hamburg, Harbor Bldg. 610, Luruper Chaussee 149, 22761Hamburg, Germany.,The Hamburg Centre of Ultrafast Imaging, Luruper Chaussee 149, 22761Hamburg, Germany
| | - Mei Bai
- The Hamburg Centre of Ultrafast Imaging, Luruper Chaussee 149, 22761Hamburg, Germany.,I. Institut für Theoretische Physik, Universität Hamburg, Notkestr. 9, 22607Hamburg, Germany
| | - Michaela Schneeberger
- Department of Chemistry, Universität Hamburg, Harbor Bldg. 610, Luruper Chaussee 149, 22761Hamburg, Germany.,The Hamburg Centre of Ultrafast Imaging, Luruper Chaussee 149, 22761Hamburg, Germany
| | - Martin Sebastian Zöllner
- Department of Chemistry, Universität Hamburg, Harbor Bldg. 610, Luruper Chaussee 149, 22761Hamburg, Germany.,The Hamburg Centre of Ultrafast Imaging, Luruper Chaussee 149, 22761Hamburg, Germany
| | - Katharina Kubicek
- The Hamburg Centre of Ultrafast Imaging, Luruper Chaussee 149, 22761Hamburg, Germany.,Department of Physics, Universität Hamburg, Notkestr. 85, 22607Hamburg, Germany.,European XFEL, Holzkoppel 4, 22869Schenefeld, Germany
| | - Henning Kirchberg
- The Hamburg Centre of Ultrafast Imaging, Luruper Chaussee 149, 22761Hamburg, Germany.,I. Institut für Theoretische Physik, Universität Hamburg, Notkestr. 9, 22607Hamburg, Germany
| | - Christian Bressler
- The Hamburg Centre of Ultrafast Imaging, Luruper Chaussee 149, 22761Hamburg, Germany.,Department of Physics, Universität Hamburg, Notkestr. 85, 22607Hamburg, Germany.,European XFEL, Holzkoppel 4, 22869Schenefeld, Germany
| | - Michael Thorwart
- The Hamburg Centre of Ultrafast Imaging, Luruper Chaussee 149, 22761Hamburg, Germany.,I. Institut für Theoretische Physik, Universität Hamburg, Notkestr. 9, 22607Hamburg, Germany
| | - Carmen Herrmann
- Department of Chemistry, Universität Hamburg, Harbor Bldg. 610, Luruper Chaussee 149, 22761Hamburg, Germany.,The Hamburg Centre of Ultrafast Imaging, Luruper Chaussee 149, 22761Hamburg, Germany
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11
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Li Y, Lv L, Yang L, He L, Chen Y, Wu L, Zhang Z. Boosting degradation and defluorination efficiencies of PFBS in a vacuum-ultraviolet/S(Ⅳ) process with iodide involvement. CHEMOSPHERE 2023; 313:137531. [PMID: 36509188 DOI: 10.1016/j.chemosphere.2022.137531] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/08/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
Perfluorobutane sulfonate (PFBS) is considered to be a promising alternative of perfluorooctane sulfonates (PFOS), while it is also hazardous. The UV/S (Ⅳ) system has been confirmed to be effective for PFOS removal from water, while it is inefficient for PFBS decomposition. A hybrid vacuum-ultraviolet (VUV)/S (Ⅳ)/KI process was investigated for the degradation of PFBS in aqueous solution. With KI involvement, the degradation rate of PFBS was boosted from 1.8802 μg h-1 up to 3.5818 μg h-1 in the VUV/S (Ⅳ) process. Alkaline conditions significantly increased the degradation efficiency of PFBS, which can be explained that S (Ⅳ) was dominated by SO32- rather than HSO3- and H2SO3 in alkaline conditions. Cl-, HCO3-, NO3-, NO2-, and HA would inhibit the performance of the VUV/S (Ⅳ)/KI process via various reactions. In addition, the toxicity of PFBS was significantly reduced by the VUV/S (Ⅳ)/KI process. Even in actual waters, the VUV/S (Ⅳ)/KI process also presented a satisfying performance in the degradation of PFBS.
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Affiliation(s)
- Yulong Li
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, PR China
| | - Lixin Lv
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, PR China
| | - Lie Yang
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, PR China.
| | - Liuyang He
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, PR China
| | - Yulin Chen
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, PR China
| | - Li Wu
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, PR China
| | - Zulin Zhang
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, PR China; The James Hutton Institute, Craigiebuckler, Aberdeen, ABI5 8QH, UK
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12
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Zhao Y, Zhang C, Chu L, Zhou Q, Huang B, Ji R, Zhou X, Zhang Y. Hydrated electron based photochemical processes for water treatment. WATER RESEARCH 2022; 225:119212. [PMID: 36223677 DOI: 10.1016/j.watres.2022.119212] [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: 07/27/2022] [Revised: 10/03/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Hydrated electron (eaq-) based photochemical processes have emerged as a promising technology for contaminant removal in water due to the mild operating conditions. This review aims to provide a comprehensive and up-to-date summary on eaq- based photochemical processes for the decomposition of various oxidative contaminants. Specifically, the characteristics of different photo-reductive systems are first elaborated, including the environment required to generate sufficient eaq-, the advantages and disadvantages of each system, and the comparison of the degradation efficiency of contaminants induced by eaq-. In addition, the identification methods of eaq- (e.g., laser flash photolysis, scavenging studies, chemical probes and electron spin resonance techniques) are summarized, and the influences of operating conditions (e.g., solution pH, dissolved oxygen, source chemical concentration and UV type) on the performance of contaminants are also discussed. Considering the complexity of contaminated water, particular attention is paid to the influence of water matrix (e.g., coexisting anions, alkalinity and humic acid). Moreover, the degradation regularities of various contaminants (e.g., perfluorinated compounds, disinfection by-products and nitrate) by eaq- are summarized. We finally put forward several research prospects for the decomposition of contaminants by eaq- based photochemical processes to promote their practical application in water treatment.
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Affiliation(s)
- Yunmeng Zhao
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Chaojie Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
| | - Liquan Chu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Qi Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Baorong Huang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Ruixin Ji
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Xuefei Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Yalei Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
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13
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Cong Y, Shen L, Wang B, Cao J, Pan Z, Wang Z, Wang K, Li Q, Li X. Efficient removal of Cr(VI) at alkaline pHs by sulfite/iodide/UV: Mechanism and modeling. WATER RESEARCH 2022; 222:118919. [PMID: 35933816 DOI: 10.1016/j.watres.2022.118919] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/16/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
Efficient removal of toxic hexavalent chromium (Cr(VI)) under alkaline conditions is still a challenge due to the relatively low reactivity of CrO42-. This study proposed a new sulfite/iodide/UV process to remove Cr(VI). The removal of Cr(VI) followed pseudo-zero-order kinetics at alkaline pHs, and was enhanced by sulfite and iodide with synergy. Compared with sulfite/UV, iodide in sulfite/iodide/UV showed about 40 times higher concentration-normalized enhancement for Cr(VI) removal, and reduced the requirement of sulfite ([S(IV)]0/[Cr(VI)]0 of about 2.1:1) by more than 90%. The Cr(VI) removal was accelerated by decreasing pH and by increasing temperature, and was slightly influenced by dissolved oxygen, carbonate, and humic acid. The process was still effective in real surface water and industrial wastewater. Mechanism and pathways of Cr(VI) removal were revealed by quenching experiments, competition kinetic analysis, product identification and quantification, and mass and electron balance. Both eaq- and SO3•- were responsible for Cr(VI) removal, making contributions of about 75% and 25%, respectively. When eaq- mainly reacted with Cr(VI), SO3•- participated in reduction of Cr(V) and Cr(IV) intermediates, with Cr(III), S2O62-, and SO42- as the final products. A model was developed to predict removal kinetics of Cr(VI), and well interpreted the roles of S(IV) and iodide in the process. This study sheds light on mechanism of Cr(VI) removal at alkaline pHs by kinetic modeling, and thus advances the applicability of this promising process for water decontamination.
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Affiliation(s)
- Yanqing Cong
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Lidong Shen
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Baimei Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Jianlai Cao
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Zixuan Pan
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Ziyu Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Kai Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Qiangbiao Li
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Xuchun Li
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China.
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14
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Huang N, Shao WT, Wang WL, Wang Q, Chen ZQ, Wu QY, Hu HY. Removal of methylisothiazolinone biocide from wastewater by VUV/UV advanced oxidation process: Kinetics, mechanisms and toxicity. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 315:115107. [PMID: 35483252 DOI: 10.1016/j.jenvman.2022.115107] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 04/15/2022] [Accepted: 04/16/2022] [Indexed: 06/14/2023]
Abstract
Methylisothiazolinone (MIT) is frequently used as antimicrobial in household and industrial products, and poses ecological and health risks to aquatic organisms and humans. In this study, vacuum ultraviolet (VUV)/ultraviolet (UV) irradiation was found highly efficient for removal of MIT. The rate constant of MIT degradation (kobs) under VUV/UV irradiation was 3.75 μEinstein-1 cm2, which was around 12.5 times higher than that under UV irradiation. The •OH concentration during the VUV/UV process was 1.0 × 10-12 M. The contributions of UV photolysis and •OH oxidation to MIT degradation under VUV/UV irradiation were 7.3% and 92.7%, respectively. The optimum solution pH (6.0-7.1) gave kobs 33%-39% higher than those at pH 3.9 and 9.3. CO32-/HCO3- inhibited MIT degradation and the kobs decreased by 74% when the concentration of CO32-/HCO3- was increased to 1 mM. The order of MIT removal efficiency under VUV/UV irradiation was ultrapure water > secondary effluent > reverse osmosis (RO) concentrate, because of the light screening and •OH quenching effect of actual wastewater. In RO concentrate, the rate constant of MIT degradation under VUV/UV irradiation was 22% higher than that obtained under UV irradiation. The reduction of TOC, UV254, and total fluorescence regional integration of the RO concentrate during VUV/UV process were 7.2%, 34.9%, and 52.3%, respectively. Twelve main transformation products of MIT were identified after VUV/UV degradation. The main degradation mechanisms of MIT were sulfur atom oxidation and hydroxyl addition. Quantitative structure-activity relationship analysis showed that VUV/UV degradation was an efficient method to remove the toxicity of MIT.
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Affiliation(s)
- Nan Huang
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing, 100084, China
| | - Wan-Ting Shao
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing, 100084, China
| | - Wen-Long Wang
- Key Laboratory of Microorganism Application and Risk Control of Shenzhen, Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, PR China.
| | - Qi Wang
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing, 100084, China
| | - Zhi-Qiang Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Qian-Yuan Wu
- Key Laboratory of Microorganism Application and Risk Control of Shenzhen, Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, PR China
| | - Hong-Ying Hu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China; Research Institute for Environmental Innovation (Suzhou), Tsinghua, Jiangsu, Suzhou, 215163, China
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15
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Biswas S, Yamijala SSRKC, Wong BM. Degradation of Per- and Polyfluoroalkyl Substances with Hydrated Electrons: A New Mechanism from First-Principles Calculations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:8167-8175. [PMID: 35481774 PMCID: PMC10365488 DOI: 10.1021/acs.est.2c01469] [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
Per- and polyfluoroalkyl substances (PFASs) are synthetic contaminants found in drinking groundwater sources and a wide variety of consumer products. Because of their adverse environmental and human health effects, remediation of these persistent compounds has attracted significant recent attention. To gain mechanistic insight into their remediation, we present the first ab initio study of PFAS degradation via hydrated electrons─a configuration that has not been correctly considered in previous computational studies up to this point. To capture these complex dynamical effects, we harness ab initio molecular dynamics (AIMD) simulations to probe the reactivities of perfluorooctanoic (PFOA) and perfluorooctane sulfonic acid (PFOS) with hydrated electrons in explicit water. We complement our AIMD calculations with advanced metadynamics sampling techniques to compute free energy profiles and detailed statistical analyses of PFOA/PFOS dynamics. Although our calculations show that the activation barrier for C-F bond dissociation in PFOS is three times larger than that in PFOA, all the computed free energy barriers are still relatively low, resulting in a diffusion-limited process. We discuss our results in the context of recent studies on PFAS degradation with hydrated electrons to give insight into the most efficient remediation strategies for these contaminants. Most importantly, we show that the degradation of PFASs with hydrated electrons is markedly different from that with excess electrons/charges, a common (but largely incomplete) approach used in several earlier computational studies.
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Affiliation(s)
- Sohag Biswas
- Department of Chemical & Environmental Engineering, Materials Science & Engineering Program, Department of Physics & Astronomy, and Department of Chemistry, University of California-Riverside, Riverside, California 92521, United States
| | - Sharma S R K C Yamijala
- Department of Chemistry and Center for Atomistic Modelling and Materials Design, Indian Institute of Technology-Madras, Chennai 6000036, India
| | - Bryan M Wong
- Department of Chemical & Environmental Engineering, Materials Science & Engineering Program, Department of Physics & Astronomy, and Department of Chemistry, University of California-Riverside, Riverside, California 92521, United States
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16
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Fennell B, Mezyk SP, McKay G. Critical Review of UV-Advanced Reduction Processes for the Treatment of Chemical Contaminants in Water. ACS ENVIRONMENTAL AU 2022; 2:178-205. [PMID: 37102145 PMCID: PMC10114900 DOI: 10.1021/acsenvironau.1c00042] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
UV-advanced reduction processes (UV-ARP) are an advanced water treatment technology characterized by the reductive transformation of chemical contaminants. Contaminant abatement in UV-ARP is most often accomplished through reaction with hydrated electrons (eaq -) produced from UV photolysis of chemical sensitizers (e.g., sulfite). In this Review, we evaluate the photochemical kinetics, substrate scope, and optimization of UV-ARP. We find that quantities typically reported in photochemical studies of natural and engineered systems are under-reported in the UV-ARP literature, especially the formation rates, scavenging capacities, and concentrations of key reactive species like eaq -. The absence of these quantities has made it difficult to fully evaluate the impact of operating conditions and the role of water matrix components on the efficiencies of UV-ARP. The UV-ARP substrate scope is weighted heavily toward contaminant classes that are resistant to degradation by advanced oxidation processes, like oxyanions and per- and polyfluoroalkyl substances. Some studies have sought to optimize the UV-ARP treatment of these contaminants; however, a thorough evaluation of the impact of water matrix components like dissolved organic matter on these optimization strategies is needed. Overall, the data compilation, analysis, and research recommendations provided in this Review will assist the UV-ARP research community in future efforts toward optimizing UV-ARP systems, modeling the eaq --based chemical transformation kinetics, and developing new UV-ARP systems.
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Affiliation(s)
- Benjamin
D. Fennell
- Zachry
Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Stephen P. Mezyk
- Department
of Chemistry and Biochemistry, California
State University, Long Beach, Long Beach, California 90840, United States
| | - Garrett McKay
- Zachry
Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States
- . Phone: 979-458-6540
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17
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Li J, Li B, Pan H, Wei Y, Yang Y, Xu N, Chen B, Mohseni M, Esfahani EB. Total organic fluorine (TOF) analysis by completely converting TOF into fluoride with vacuum ultraviolet. JOURNAL OF HAZARDOUS MATERIALS 2022; 429:128389. [PMID: 35236042 DOI: 10.1016/j.jhazmat.2022.128389] [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: 11/03/2021] [Revised: 01/17/2022] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Quantifying total organic fluorine (TOF) in water is vital in monitoring the occurrence and persistence of all fluorine-containing organic compounds in the environment, while currently most studies focus on analyzing individual fluorine-containing organic compounds. To fill the technology gap, we herein proposed to convert TOF completely into fluoride with vacuum ultraviolet (VUV) photolysis, followed by analysis of fluoride with ion chromatography. Results showed that the tailored VUV photoreactor achieved satisfying recoveries of fluorine from ten model TOF compounds not only in ultrapure water (83.9 ± 2.0% to 109.4 ± 0.8%) but also in real water samples (92.1 ± 1.0%-106.2 ± 15.7%). Unlike other ultraviolet-based processes that favor alkaline conditions, this VUV process preferred either neutral or acidic conditions to defluorinate selected compounds. While the mechanisms remain to be explored in the future, it has been evidenced that the photo-degradation and photo-defluorination rates of these TOF compounds varied significantly among compounds and operation conditions. The method obtained a method detection limit (MDL) of 0.15 μg-F/L, which is lower than the MDLs of many other TOF analytical methods, along with excellent calibration curves for concentrations ranging from 0.01 to 10.0 mg-F/L. Notably, minimizing fluoride in sample prior to photoconversion was necessary to avoid subtraction-induced errors for TOF measurement, especially when the fluoride/TOF ratio was high. The robust VUV is also green for sample pretreatment due to its unreliance of chemicals or additives.
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Affiliation(s)
- Juan Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Shenzhen 518055, China
| | - Boqiang Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Shenzhen 518055, China
| | - Huimei Pan
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Shenzhen 518055, China
| | - Yiya Wei
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Shenzhen 518055, China
| | - Yang Yang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Shenzhen 518055, China
| | - Nan Xu
- School of Environment and Energy, Peking University, China
| | - Baiyang Chen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Shenzhen 518055, China.
| | - Madjid Mohseni
- Department of Chemical & Biological Engineering University of British Columbia Vancouver, BC V6T 1Z3, Canada
| | - Ehsan Banayan Esfahani
- Department of Chemical & Biological Engineering University of British Columbia Vancouver, BC V6T 1Z3, Canada
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18
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19
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Liu Z, Chen Z, Gao J, Yu Y, Men Y, Gu C, Liu J. Accelerated Degradation of Perfluorosulfonates and Perfluorocarboxylates by UV/Sulfite + Iodide: Reaction Mechanisms and System Efficiencies. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:3699-3709. [PMID: 35226468 PMCID: PMC9481055 DOI: 10.1021/acs.est.1c07608] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The addition of iodide (I-) in the UV/sulfite system (UV/S) significantly accelerated the reductive degradation of perfluorosulfonates (PFSAs, CnF2n+1SO3-) and perfluorocarboxylates (PFCAs, CnF2n+1COO-). Using the highly recalcitrant perfluorobutane sulfonate (C4F9SO3-) as a probe, we optimized the UV/sulfite + iodide system (UV/S + I) to degrade n = 1-7 PFCAs and n = 4, 6, 8 PFSAs. In general, the kinetics of per- and polyfluoroalkyl substance (PFAS) decay, defluorination, and transformation product formations in UV/S + I were up to three times faster than those in UV/S. Both systems achieve a similar maximum defluorination. The enhanced reaction rates and optimized photoreactor settings lowered the EE/O for PFCA degradation below 1.5 kW h m-3. The relatively high quantum yield of eaq- from I- made the availability of hydrated electrons (eaq-) in UV/S + I and UV/I two times greater than that in UV/S. Meanwhile, the rapid scavenging of reactive iodine species by SO32- made the lifetime of eaq- in UV/S + I eight times longer than that in UV/I. The addition of I- also substantially enhanced SO32- utilization in treating concentrated PFAS. The optimized UV/S + I system achieved >99.7% removal of most PFSAs and PFCAs and >90% overall defluorination in a synthetic solution of concentrated PFAS mixtures and NaCl. We extended the discussion over molecular transformation mechanisms, development of PFAS degradation technologies, and the fate of iodine species.
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Affiliation(s)
- Zekun Liu
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Zhanghao Chen
- State
Key Laboratory of Pollution Control and Resource Reuse, School of
the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Jinyu Gao
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Yaochun Yu
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
- Department
of Civil & Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yujie Men
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
- Department
of Civil & Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Cheng Gu
- State
Key Laboratory of Pollution Control and Resource Reuse, School of
the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Jinyong Liu
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
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20
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Ranjan S, Kufner CL, Lozano GG, Todd ZR, Haseki A, Sasselov DD. UV Transmission in Natural Waters on Prebiotic Earth. ASTROBIOLOGY 2022; 22:242-262. [PMID: 34939825 PMCID: PMC8968845 DOI: 10.1089/ast.2020.2422] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 09/28/2021] [Indexed: 05/10/2023]
Abstract
Ultraviolet (UV) light plays a key role in surficial theories of the origin of life, and numerous studies have focused on constraining the atmospheric transmission of UV radiation on early Earth. However, the UV transmission of the natural waters in which origins-of-life chemistry (prebiotic chemistry) is postulated to have occurred is poorly constrained. In this work, we combine laboratory and literature-derived absorption spectra of potential aqueous-phase prebiotic UV absorbers with literature estimates of their concentrations on early Earth to constrain the prebiotic UV environment in marine and terrestrial natural waters, and we consider the implications for prebiotic chemistry. We find that prebiotic freshwaters were largely transparent in the UV, contrary to assumptions in some models of prebiotic chemistry. Some waters, such as high-salinity waters like carbonate lakes, may be deficient in shortwave (≤220 nm) UV flux. More dramatically, ferrous waters can be strongly UV-shielded, particularly if the Fe2+ forms highly UV-absorbent species such as F e C N 6 4 - . Such waters may be compelling venues for UV-averse origin-of-life scenarios but are unfavorable for some UV-dependent prebiotic chemistries. UV light can trigger photochemistry even if attenuated through photochemical transformations of the absorber (e.g., e a q - production from halide irradiation), which may have both constructive and destructive effects for prebiotic syntheses. Prebiotic chemistries that invoke waters that contain such absorbers must self-consistently account for the chemical effects of these transformations. The speciation and abundance of Fe2+ in natural waters on early Earth is a major uncertainty and should be prioritized for further investigation, as it played a major role in UV transmission in prebiotic natural waters.
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Affiliation(s)
- Sukrit Ranjan
- Department of Earth, Atmospheric & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Physics and Astronomy, Center for Interdisciplinary Exploration and Research in Astrophysics, Northwestern University, Evanston, Illinois, USA
- Blue Marble Space Institute of Science, Seattle, Washington, USA
| | - Corinna L. Kufner
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA
| | | | - Zoe R. Todd
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, USA
| | - Azra Haseki
- Department of Earth, Atmospheric & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Harvard College, Cambridge, Massachusetts, USA
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21
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Bachman B, Zhu D, Bandy J, Zhang L, Hamers RJ. Detection of Aqueous Solvated Electrons Produced by Photoemission from Solids Using Transient Absorption Measurements. ACS MEASUREMENT SCIENCE AU 2022; 2:46-56. [PMID: 36785590 PMCID: PMC9838729 DOI: 10.1021/acsmeasuresciau.1c00025] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Solvated electrons in water have long been of interest to chemists. While readily produced using intense multiphoton excitation of water and/or irradiation with high-energy particles, the possible role of solvated electrons in electrochemical and photoelectrochemical reactions at electrodes has been controversial. Recent studies showed that excitation of electrons to the conduction band of diamond leads to barrier-free emission of electrons into water. While these electrons can be inferred from the reactions they induce, direct detection by transient absorption measurements provides more direct evidence. Here, we present studies demonstrating direct detection of solvated electrons produced at diamond electrode surfaces and the influence of electrochemical potential and solution-phase electron scavengers. We further present a more detailed analysis of experimental conditions needed to detect solvated electrons emitted from diamond and other solid materials through transient optical absorption measurements.
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22
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Chen H, Lin T, Yan X, Xu H. Elevated risk of haloacetonitrile formation during post-chlorination when applying sulfite/UV advanced reduction technology to eliminate bromate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150612. [PMID: 34597579 DOI: 10.1016/j.scitotenv.2021.150612] [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: 05/25/2021] [Revised: 09/19/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
The formation of haloacetonitriles (HANs) during chlorination after sulfite/ultraviolet (UV) treatment of bromate (BrO3-) in the presence of amino acids (AAs) was investigated. During sulfite/UV treatment, the primary species hydrated electrons (eaq-) and hydrogen atom radicals (H) dominated the reduction of BrO3- to bromide (Br-), whereas the sulfite anion radicals (SO3-) and H degraded AAs to produce the intermediates HN=C(CH3)-COOH, CH3-CH=NH, and CH3-C≡N via α‑hydrogen abstraction and NH2-hydrogen abstraction mechanisms. During post-chlorination, Br- was converted to HBrO/BrO-, and the HN=C(CH3)-COOH, CH3-CH=NH, and CH3-C≡N groups featured higher bromine utilization factor (BUF) and chlorine utilization factor (CUF) values than AAs, enhancing the formation of dibromoacetonitrile (DBAN) and dichloroacetonitrile (DCAN). The energetic feasibility of the transformation pathway, that is, HN=C(CH3)-COOH, CH3-CH=NH, and CH3-C ≡ N formation via hydrogen abstraction by SO3- and H and their further conversion to HANs, was proved by density functional theory calculations, which showed stepwise negative Gibbs free energy changes (ΔG < 0). The effects of pH and water matrices (e.g., HCO3-, Cl-, Fe3+, and natural organic matter) were comprehensively evaluated. Although 72% of BrO3- was removed by sulfite/UV treatment in the presence of AAs, the cytotoxicity index (CTI) and genotoxicity index (GTI) during post-chlorination increased by 213% and 125%, respectively, due to the formation of 24 CX3R-type disinfection by-products (DBPs), especially brominated DBPs. Accordingly, more attention should be given to the formation of brominated DBPs during post-chlorination when using sulfite/UV processes to remove BrO3- in the presence of AAs. As a solution, using monochloramine instead of chlorine as a disinfectant after the sulfite/UV process could significantly lower the CTI and GTI values by alleviating the formation of brominated DBPs.
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Affiliation(s)
- Han Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Tao Lin
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Xiaoshu Yan
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Hang Xu
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
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Reductive and Oxidative UV Degradation of PFAS—Status, Needs and Future Perspectives. WATER 2021. [DOI: 10.3390/w13223185] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) consist of a group of environmentally persistent, toxic and bio-accumulative organic compounds of industrial origin that are widely present in water and wastewater. Despite restricted use due to current regulations on their use, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) remain the most commonly detected long-chain PFAS. This article reviews UV-based oxidative and reductive studies for the degradation of PFAS. Most of the UV-based processes studied at lab-scale include low pressure mercury lamps (emitting at 254 and 185 nm) with some studies using medium pressure mercury lamps (200–400 nm). A critical evaluation of the findings is made considering the degradation of PFAS, the impact of water quality conditions (pH, background ions, organics), types of oxidizing/reducing species, and source of irradiation with emphasis given to mechanisms of degradation and reaction by-products. Research gaps related to understanding of the factors influencing oxidative and reductive defluorination, impact of co-existing ions from the perspective of complexation with PFAS, and post-treatment toxicity are highlighted. The review also provides an overview of future perspectives regarding the challenges in relation to the current knowledge gaps, and future needs.
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24
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Nur-E-Habiba, Uddin R, Salminen K, Sariola V, Kulmala S. Carbon Particle-Doped Polymer Layers on Metals as Chemically and Mechanically Resistant Composite Electrodes for Hot Electron Electrochemistry. J ELECTROCHEM SCI TE 2021. [DOI: 10.33961/jecst.2021.00640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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25
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Xu J, Green NJ, Russell DA, Liu Z, Sutherland JD. Prebiotic Photochemical Coproduction of Purine Ribo- and Deoxyribonucleosides. J Am Chem Soc 2021; 143:14482-14486. [PMID: 34469129 PMCID: PMC8607323 DOI: 10.1021/jacs.1c07403] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
![]()
The
hypothesis that life on Earth may have started with a heterogeneous
nucleic acid genetic system including both RNA and DNA has attracted
broad interest. The recent finding that two RNA subunits (cytidine,
C, and uridine, U) and two DNA subunits (deoxyadenosine, dA, and deoxyinosine,
dI) can be coproduced in the same reaction network, compatible with
a consistent geological scenario, supports this theory. However, a
prebiotically plausible synthesis of the missing units (purine ribonucleosides
and pyrimidine deoxyribonucleosides) in a unified reaction network
remains elusive. Herein, we disclose a strictly stereoselective and
furanosyl-selective synthesis of purine ribonucleosides (adenosine,
A, and inosine, I) and purine deoxynucleosides (dA and dI), alongside
one another, via a key photochemical reaction of thioanhydroadenosine
with sulfite in alkaline solution (pH 8–10). Mechanistic studies
suggest an unexpected recombination of sulfite and nucleoside alkyl
radicals underpins the formation of the ribo C2′–O bond.
The coproduction of A, I, dA, and dI from a common intermediate, and
under conditions likely to have prevailed in at least some primordial
locales, is suggestive of the potential coexistence of RNA and DNA
building blocks at the dawn of life.
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Affiliation(s)
- Jianfeng Xu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, U.K
| | - Nicholas J Green
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, U.K
| | - David A Russell
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, U.K
| | - Ziwei Liu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, U.K
| | - John D Sutherland
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, U.K
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26
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Green NJ, Xu J, Sutherland JD. Illuminating Life's Origins: UV Photochemistry in Abiotic Synthesis of Biomolecules. J Am Chem Soc 2021; 143:7219-7236. [PMID: 33880920 PMCID: PMC8240947 DOI: 10.1021/jacs.1c01839] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Indexed: 01/15/2023]
Abstract
Solar radiation is the principal source of energy available to Earth and has unmatched potential for the synthesis of organic material from primordial molecular building blocks. As well as providing the energy for photochemical synthesis of (proto)biomolecules of interest in origins of life-related research, light has also been found to often provide remarkable selectivity in these processes, for molecules that function in extant biology and against those that do not. As such, light is heavily implicated as an environmental input on the nascent Earth that was important for the emergence of complex yet selective chemical systems underpinning life. Reactivity and selectivity in photochemical prebiotic synthesis are discussed, as are their implications for origins of life scenarios and their plausibility, and the future directions of this research.
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Affiliation(s)
- Nicholas J. Green
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge
Biomedical Campus, Cambridge CB2 0QH, U.K.
| | - Jianfeng Xu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge
Biomedical Campus, Cambridge CB2 0QH, U.K.
| | - John D. Sutherland
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge
Biomedical Campus, Cambridge CB2 0QH, U.K.
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Tang LZ, Lin YL, Xu B, Xia Y, Zhang TY, Hu CY, Tang YL, Cao TC, Xian QM, Gao NY. Photodegradation pathway of iodate and formation of I-THMs during subsequent chloramination in iodate-iodide-containing water. WATER RESEARCH 2021; 193:116851. [PMID: 33540343 DOI: 10.1016/j.watres.2021.116851] [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: 11/10/2020] [Revised: 01/15/2021] [Accepted: 01/16/2021] [Indexed: 06/12/2023]
Abstract
This study investigated the mechanisms of mixed IO3-/I- system under UV irradiation in drinking water and compared the iodinated trihalomethanes (I-THMs) formation of a mixed IO3-/I- system to that of single I- and IO3- systems during subsequent chloramination. The effects of initial I-/IO3- molar ratio, pH, and UV intensity on a mixed IO3-/I- system were studied. The introduction of I- enhanced the conversion rate of IO3- to reactive iodine species (RIS). Besides, IO3- degradation rate increased with the increase of initial I- concentration and UV intensity and the decrease of pH value. In a mixed IO3-/I- system, IO3- could undergo direct photolysis and photoreduction by hydrated electron (eaq-). Moreover, the enhancement of I-THM formation in a mixed IO3-/I- system during subsequent chloramination was observed. The I-THM yields in a mixed IO3-/I- system were higher than the sum of I-THMs produced in a single IO3- and I- systems at all the evaluated initial I- concentrations and pH values. The difference between I-THM formation in a mixed IO3-/I- system and the sum of I-THMs in a single IO3- and I- systems increased with the increase of initial I- concentration. As the initial pH decreased from 9 to 5, the difference of I-THM yields enhanced, while the total I-THM yield of a mixed IO3-/I- system and single I- and IO3- systems decreased slightly. Besides, IO3--I--containing water with DOC concentration of 2.5-4.5 mg-C/L, which mainly contained humic-acid substances, had a higher risk in I-THMs formation than individual I--containing and IO3--containing water.
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Affiliation(s)
- Li-Zhen Tang
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P.R. China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P.R. China
| | - Yi-Li Lin
- Department of Safety, Health and Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 824, Taiwan, R.O.C
| | - Bin Xu
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P.R. China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P.R. China
| | - Ying Xia
- Shanghai Chengtou Raw Water Co., Ltd., Shanghai 200125, P.R. China
| | - Tian-Yang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P.R. China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P.R. China
| | - Chen-Yan Hu
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, P. R. China
| | - Yu-Lin Tang
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P.R. China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P.R. China
| | - Tong-Cheng Cao
- School of Chemical Science and Engineering, Key Laboratory of Road and Traffic Engineering of Ministry of Education, Tongji University, Shanghai 200092, P.R. China
| | - Qi-Ming Xian
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, P. R. China
| | - Nai-Yun Gao
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P.R. China
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28
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Li J, Zhang Q, Chen B, Wang L, Zhu R, Yang J. Hydrogen peroxide formation in water during the VUV/UV irradiation process: Impacts and mechanisms of selected anions. ENVIRONMENTAL RESEARCH 2021; 195:110751. [PMID: 33472042 DOI: 10.1016/j.envres.2021.110751] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/14/2020] [Accepted: 01/12/2021] [Indexed: 06/12/2023]
Abstract
Understanding the formation and transformation of radicals generated by a low pressure mercury lamp emitting both 254 nm ultraviolet (UV254) and 185 nm vacuum UV (VUV185) is currently challenging due to the complexity of concurrent redox reactions occurring in this complex system. Because hydrogen peroxide (H2O2) is a common product of both oxidizing and reducing radicals generated during the VUV irradiation process, monitoring the variations in H2O2 levels can help us better understand the presence and relative dominance of different radicals. In this study, we systematically evaluated the effects of several selected anions on the formation of H2O2 under a variety of pH and dissolved oxygen (DO) conditions. Results show that although addition of these anions inhibited the formation of H2O2, their H2O2-inhibition mechanisms are markedly different. At low concentrations (≤1.0 mg/L), chloride reduced the generation of H2O2 primarily by consuming hydroxyl radicals (•OH); however, in high concentrations (11.0 mg/L), its light-screening effect was dominant. In comparison, the presence of bromide (≤1.0 mg/L) inhibited H2O2 formation mainly by reacting rapidly with both •OH and H2O2. Carbonate and phosphorous species exerted influence mainly by consuming •OH. Along with irradiation, increasing pH significantly decreased H2O2 levels, confirming that H2O2 was formed mainly by •OH. In contrast, raising DO did not raise H2O2 maximum yields, confirming that reducing radicals like aqueous electrons (e-aq) and hydrogen atoms (•H) are not the key precursors of H2O2 in this process. Mathematically, the evolutions of H2O2 can be reliably modeled (R2 ≥ 0.80) using a kinetics model incorporating H2O2 formation and decomposition kinetics. The results of this study may contribute to better understanding the use of VUV technology in water/wastewater treatment.
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Affiliation(s)
- Juan Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), 518055, China
| | - Qi Zhang
- 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.
| | - Lei Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), 518055, China
| | - Rongshu Zhu
- 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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29
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Liang S, Xu S, Wang C, Ling J, Xian Z, Wu H, Tian H, Zhou S, Gu C. Enhanced alteration of poly(vinyl chloride) microplastics by hydrated electrons derived from indole-3-acetic acid assisted by a common cationic surfactant. WATER RESEARCH 2021; 191:116797. [PMID: 33422976 DOI: 10.1016/j.watres.2020.116797] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 06/12/2023]
Abstract
In this study, a new photo-irradiated reductive dechlorination pathway and the underlying transformation mechanism are described for poly(vinyl chloride) microplastics (PVC-MPs). PVC-MPs underwent photo-reductive dechlorination process with the release of chloride ions. This reaction could be facilitated in the presence of indole-3-acetic acid (IAA) and hexadecyltrimethylammonium bromide (CTAB) under neutral pH and simulated sunlight irradiation conditions. Electrostatic interaction between IAA and CTAB produced neutral IAA/CTAB complex, which might account for the enhanced adsorption of IAA on PVC powders. Upon photo-irradiation, the adsorbed IAA was excited to generate hydrated electrons (eaq-), which could pass through a shorter distance to PVC-MP surface than that derived from homogeneous IAA molecules in aqueous solution. Transient spectra of laser flash photolysis provided direct evidence for the generation of eaq-, which supported the proposed dechlorination mechanism. Based on the results of attenuated total reflectance/Fourier transform infrared (ATR/FTIR) and Raman spectra, C-Cl bond cleavage and polyene formation were involved in the structural transformation of PVC-MPs. Due to the hydrophobic effects and π-π interactions between aromatic rings and polyene structures in PVC-MP surface, the PVC-MP powders irradiated in the presence of IAA/CTAB showed an enhanced sorption for both hydrophobic and hydrophilic aromatic chemicals.
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Affiliation(s)
- Sijia Liang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Shuxia Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Chao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
| | - Jingyi Ling
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Zeyu Xian
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Hao Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Haoting Tian
- Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection, College of Resource and Environment, Linyi University, Linyi 276005, PR China
| | - Shaoda Zhou
- Nanjing Kaver Scientific Instruments, Institute of Forestry Chemical Industry, China Academy of Forestry, Nanjing 210042, PR China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
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30
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Cao Y, Qiu W, Li J, Zhao Y, Jiang J, Pang S. Sulfite enhanced transformation of iopamidol by UV photolysis in the presence of oxygen: Role of oxysulfur radicals. WATER RESEARCH 2021; 189:116625. [PMID: 33227612 DOI: 10.1016/j.watres.2020.116625] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/09/2020] [Accepted: 11/07/2020] [Indexed: 06/11/2023]
Abstract
UV/sulfite process in the absence of oxygen was previously applied as an advanced reduction process for the removal of many halogenated organics and inorganics in water and wastewater. Here, it was found that UV/sulfite process in the presence of oxygen could act as an advanced oxidation process. Specifically, the oxysulfur radicals (including sulfate radical (SO4·-) and sulfite/peroxomonosulfate radicals (SO3·-/SO5·-)) played important roles on the degradation of iopamidol (IPM) as a typical iodinated contrast media (ICM). Furthermore, the contribution of SO4·- on IPM removal gradually increased as pH increased from 5 to 7 and that of SO3·-/SO5·- decreased. Besides, all water quality parameters (i.e., chloride (Cl-), iodide (I-) and natural organic matter (NOM)) investigated here exhibited inhibitory effect on IPM removal. Three inorganic iodine species (i.e., I-, reactive iodine species and iodate (IO3-)) were detected in UV/sulfite process in the presence of oxygen, while only I- was detected in that without oxygen. During UV/sulfite/ethanol, UV photolysis and UV/peroxydisulfate (PDS)/tert-butyl alcohol (TBA) processes, thirteen transformation products including eleven deiodinated products of IPM were identified by ultra HPLC quadrupole time of flight-mass spectrometry (UPLC-Q-TOF-MS). Besides, these products generated by direct UV photolysis, SO4·- and SO3·-/SO5·- were further distinguished. The acute toxicity assay of Vibrio fischeri indicated that transformation products by UV/sulfite under aerobic conditions were less toxic than that by direct UV photolysis.
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Affiliation(s)
- Ying Cao
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Wei Qiu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Juan Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yumeng Zhao
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jin Jiang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
| | - Suyan Pang
- Key Laboratory of Songliao Aquatic Environment, Ministry of Education, School of Municipal and Environmental Engineering, Jilin Jianzhu University, Changchun, 130118, China
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31
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Rao U, Su Y, Khor CM, Jung B, Ma S, Cwiertny DM, Wong BM, Jassby D. Structural Dependence of Reductive Defluorination of Linear PFAS Compounds in a UV/Electrochemical System. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:10668-10677. [PMID: 32786552 DOI: 10.1021/acs.est.0c02773] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Per and polyfluoroalkyl substances (PFAS), legacy chemicals used in firefighting and the manufacturing of many industrial and consumer goods, are widely found in groundwater resources, along with other regulated compounds, such as chlorinated solvents. Due to their strong C-F bonds, these molecules are extremely recalcitrant, requiring advanced treatment methods for effective remediation, with hydrated electrons shown to be able to defluorinated these compounds. A combined photo/electrochemical method has been demonstrated to dramatically increase defluorination rates, where PFAS molecules sorbed onto appropriately functionalized cathodes charged to low cell potentials (-0.58 V vs Ag/AgCl) undergo a transient electron transfer event from the electrode, which "primes" the molecule by reducing the C-F bond strength and enables the bond's dissociation upon the absorption of a hydrated electron. In this work, we explore the impact of headgroup and chain length on the performance of this two-electron process and extend this technique to chlorinated solvents. We use isotopically labeled PFAS molecules to take advantage of the kinetic isotope effect and demonstrate that indeed PFAS defluorination is likely driven by a two-electron process. We also present density functional theory calculations to illustrate that the externally applied potential resulted in an increased rate of electron transfer, which ultimately increased the measured defluorination rate.
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Affiliation(s)
- Unnati Rao
- Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095-153, United States
| | - Yiming Su
- Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095-153, United States
| | - Chia Miang Khor
- Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095-153, United States
| | - Bongyeon Jung
- Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095-153, United States
| | - Shengcun Ma
- Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095-153, United States
| | - David M Cwiertny
- Department of Civil and Environmental Engineering, University of Iowa, Iowa City, Iowa 52242, United States
| | - Bryan M Wong
- Department of Chemical & Environmental Engineering, Materials Science & Engineering Program, University of California, Riverside, California 92521, United States
| | - David Jassby
- Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095-153, United States
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32
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Selective prebiotic formation of RNA pyrimidine and DNA purine nucleosides. Nature 2020; 582:60-66. [PMID: 32494078 DOI: 10.1038/s41586-020-2330-9] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/16/2020] [Indexed: 11/08/2022]
Abstract
The nature of the first genetic polymer is the subject of major debate1. Although the 'RNA world' theory suggests that RNA was the first replicable information carrier of the prebiotic era-that is, prior to the dawn of life2,3-other evidence implies that life may have started with a heterogeneous nucleic acid genetic system that included both RNA and DNA4. Such a theory streamlines the eventual 'genetic takeover' of homogeneous DNA from RNA as the principal information-storage molecule, but requires a selective abiotic synthesis of both RNA and DNA building blocks in the same local primordial geochemical scenario. Here we demonstrate a high-yielding, completely stereo-, regio- and furanosyl-selective prebiotic synthesis of the purine deoxyribonucleosides: deoxyadenosine and deoxyinosine. Our synthesis uses key intermediates in the prebiotic synthesis of the canonical pyrimidine ribonucleosides (cytidine and uridine), and we show that, once generated, the pyrimidines persist throughout the synthesis of the purine deoxyribonucleosides, leading to a mixture of deoxyadenosine, deoxyinosine, cytidine and uridine. These results support the notion that purine deoxyribonucleosides and pyrimidine ribonucleosides may have coexisted before the emergence of life5.
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Ritson DJ, Mojzsis SJ, Sutherland JD. Supply of phosphate to early Earth by photogeochemistry after meteoritic weathering. NATURE GEOSCIENCE 2020; 13:344-348. [PMID: 32395178 PMCID: PMC7213494 DOI: 10.1038/s41561-020-0556-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 02/19/2020] [Indexed: 05/24/2023]
Abstract
During terrestrial differentiation, the relatively small amount of phosphorus that migrated to the lithosphere was incorporated into igneous rock, predominantly in the form of basic calcium orthophosphate (Ca10(PO4)6(OH,F,Cl)2, apatite). Yet, the highly insoluble nature of calcium apatite presents a significant problem to those contemplating the origin of life given the foundational role of phosphate (PO4 3-) in extant biology and the apparent requirement for PO4 3- as a catalyst, buffer and reagent in prebiotic chemistry. Reduced meteorites such as enstatite chondrites are highly enriched in phosphide minerals, and upon reaction with water these minerals can release phosphorus species of various oxidation states. Here, we demonstrate how reduced phosphorus species can be fully oxidized to PO4 3- simply by the action of ultraviolet light on H2S/HS-. We used low pressure Hg lamps to simulate UV output from the young Sun and 31P NMR spectroscopy to monitor the progress of reactions. Our experimental findings provide a cosmochemically and geochemically plausible means for supply of PO4 3- that was widely available to prebiotic chemistry and nascent life on early Earth, and potentially on other planets.
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Affiliation(s)
- Dougal J. Ritson
- MRC – Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, U.K
| | - Stephen J. Mojzsis
- Department of Geological Sciences, University of Colorado, UCB 399, 2200 Colorado Avenue, Boulder, CO 80309-0399, USA
- Institute for Geological and Geochemical Research, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, 45 Budaörsi Street, H-1112 Budapest, Hungary
| | - John. D. Sutherland
- MRC – Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, U.K
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Wang L, Zhang Q, Chen B, Bu Y, Chen Y, Ma J, Rosario-Ortiz FL, Zhu R. Some issues limiting photo(cata)lysis application in water pollutant control: A critical review from chemistry perspectives. WATER RESEARCH 2020; 174:115605. [PMID: 32078833 DOI: 10.1016/j.watres.2020.115605] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/05/2020] [Accepted: 02/10/2020] [Indexed: 06/10/2023]
Abstract
For decades, photolysis and photocatalysis have been touted as promising environment-benign and robust technologies to degrade refractory pollutants from water. However, extensive, large-scale engineering applications remain limited now. To facilitate the technology transfer process, earlier reviews have advocated to developing more cost-effective and innocuous materials, maximizing efficiency of photon usage, and optimizing photoreactor systems, mostly from material and reactor improvement perspectives. However, there are also some fundamental yet critical chemistry issues in photo(cata)lysis processes demanding more in-depth understanding and more careful consideration. Hence, this review summarizes some of these challenges. Of them, the first and paramount issue is the interference of coexisting compounds, including dissolved organic matter, anions, cations, and spiked additives. Secondly, considerable concerns are pointed to the formation of undesirable reaction by-products, such as halogenated, nitrogenous, and sulfur-containing compounds, which might increase instead of reduce toxicity of water if inadequate fluence and catalyst/additive are supplied due to time and cost constraints. Lastly, a critical issue lies in the uncertainty of current approaches used for identifying and quantifying radicals, especially when multiple radicals coexist together under changing and interconvertible conditions. The review hence highlights the needs to better understand these fundamental chemistry issues and meanwhile calls for more delicate design of experiments in future studies to overcome these barriers.
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Affiliation(s)
- Lei Wang
- Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Qi Zhang
- Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Baiyang Chen
- Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen, 518055, China.
| | - Yinan Bu
- Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Yi Chen
- Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Fernando L Rosario-Ortiz
- Department of Civil, Environmental and Architectural Engineering, 428 UCB, University of Colorado, Boulder, CO, 80309, United States
| | - Rongshu Zhu
- Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen, 518055, China.
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Zhang Q, Wang L, Chen B, Chen Y, Ma J. Understanding and modeling the formation and transformation of hydrogen peroxide in water irradiated by 254 nm ultraviolet (UV) and 185 nm vacuum UV (VUV): Effects of pH and oxygen. CHEMOSPHERE 2020; 244:125483. [PMID: 31816545 DOI: 10.1016/j.chemosphere.2019.125483] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/11/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
Understanding ultraviolet photolysis induced by low pressure mercury lamp that emits both 254 nm ultraviolet (UV254) and 185 nm vacuum UV (VUV185) is currently challenging due to the copresence of multiple direct and indirect photochemical processes involving a series of highly-reactive radicals. Herein we examined the formation and transformation of H2O2 in water, which is both a precursor and a product of radicals, under various pH and dissolved oxygen (DO) conditions. The trends show that H2O2 increased rapidly at early stage and then remained steady in DO-rich water or declined somewhat in DO-poor water, ultimately leading to higher steady-state H2O2 in DO-rich water. The maximum H2O2 contents nonetheless were similar among waters with different DO, suggesting that H2O2 in this system was mostly generated by hydroxyl radical (OH) recombination, which is an oxygen-independent H2O2 formation pathway, rather than by reduced oxygen via hydrogen atom (H) or hydrated electron (eaq-), which is an oxygen-dependent pathway. Increasing pH (from 6.3 to 10.0) or bicarbonate dosage dramatically decreased H2O2 formation too. Mathematically, the fates of H2O2 as a function of pH, DO, and time were well modeled (R2 ≥ 0.92), in which the rates of H2O2 formation and destruction were greater in DO-poor water than those in DO-rich water. In addition, we found that the steady-state concentrations of OH used for degradation of p-chlorobenzoic acid, an OH probe, correlated well with the OH levels used for H2O2 formation (R2 = 0.98). These results hence may help better understand the UV/VUV process via H2O2 evolutions.
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Affiliation(s)
- Qi Zhang
- Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Lei Wang
- Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Baiyang Chen
- Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen, 518055, China.
| | - Yi Chen
- Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
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Maza WA, Breslin VM, Plymale NT, DeSario PA, Epshteyn A, Owrutsky JC, Pate BB. Nanosecond transient absorption studies of the pH-dependent hydrated electron quenching by HSO 3. Photochem Photobiol Sci 2019; 18:1526-1532. [PMID: 30984955 DOI: 10.1039/c9pp00063a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The large standard reduction potential of an aqueous solvated electron (eaq-, E° = -2.9 V) makes it an attractive candidate for reductive treatment of wastewater contaminants. Using transient absorption spectroscopy, the nanosecond to microsecond dynamics of eaq- generated from 10 mM solutions of Na2SO3 at pH 4 to 11 in H2O and D2O are characterized, resulting in the determination that between pH 4 and 9 it is the HSO3-, and not H+ as previously postulated by others, that effectively quenches eaq-. The observed bimolecular quenching rate constant (k = 1.2 × 108 M-1 s-1) for eaq- deactivation by HSO3- is found to be consistent with a Brønsted acid catalysis mechanism resulting in formation of H˙ and SO32-. A large solvent isotope effect is observed from the lifetimes of the eaq- in H2O compared to D2O (kH2O/kD2O = 4.4). In addition, the bimolecular rate constant for eaq- deactivation by DSO3- (k = 2.7 × 107 M-1 s-1) is found to be an order of magnitude lower than by HSO3-. These results highlight the role of acids, such as HSO3-, in competition with organic contaminant targets for eaq- and, by extension, that knowledge of the pKa of eaq- sources can be a predictive measure of the effective pH range for the treatment of wastewater contaminants.
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Affiliation(s)
- William A Maza
- National Research Council, U.S. Naval Research Laboratory, Washington, D.C. 20375, USA.
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Xu J, Green NJ, Gibard C, Krishnamurthy R, Sutherland JD. Prebiotic phosphorylation of 2-thiouridine provides either nucleotides or DNA building blocks via photoreduction. Nat Chem 2019; 11:457-462. [PMID: 30936523 DOI: 10.1038/s41557-019-0225-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 01/25/2019] [Indexed: 11/09/2022]
Abstract
Breakthroughs in the study of the origin of life have demonstrated how some of the building blocks essential to biology could have been formed under various primordial scenarios, and could therefore have contributed to the chemical evolution of life. Missing building blocks are then sometimes inferred to be products of primitive biosynthesis, which can stretch the limits of plausibility. Here, we demonstrate the synthesis of 2'-deoxy-2-thiouridine, and subsequently 2'-deoxyadenosine and 2-deoxyribose, under prebiotic conditions. 2'-Deoxy-2-thiouridine is produced by photoreduction of 2,2'-anhydro-2-thiouridine, which is in turn formed by phosphorylation of 2-thiouridine-an intermediate of prebiotic RNA synthesis. 2'-Deoxy-2-thiouridine is an effective deoxyribosylating agent and may have functioned as such in either abiotic or proto-enzyme-catalysed pathways to DNA, as demonstrated by its conversion to 2'-deoxyadenosine by reaction with adenine, and 2-deoxyribose by hydrolysis. An alternative prebiotic phosphorylation of 2-thiouridine leads to the formation of its 5'-phosphate, showing that hypotheses in which 2-thiouridine was a key component of early RNA sequences are within the bounds of synthetic credibility.
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Affiliation(s)
- Jianfeng Xu
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | | | - Clémentine Gibard
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
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Abstract
Bromate ( BrO 3 − ) residue in drinking water poses a great health risk. Ultra-fast reduction of BrO 3 − , under aerobic conditions, was realized using an ultraviolet (UV)/sulfite process in the presence of iodide (UV/sulfite/iodide). The UV/sulfite/iodide process produced BrO 3 − removal efficiency of 100% at about 5 min with complete conversion to bromide, while UV/sulfite induced 13.1% BrO 3 − reduction under the same conditions. Hydrated electrons, generated from the photolysis of sulfite and iodide, was confirmed as the main contributor to BrO 3 − degradation (77.4% of the total contribution). As the concentration of iodide was kept constant, its presence remarkably enhancing the generation of hydrated electrons led to its consideration as a homogeneous catalyst in the UV/sulfite/iodide system. Sulfite played a role not only as a hydrated electron precursor, but also as a reactive iodine species shielding agent and a regenerant of iodide. Results surrounding the effects on common water quality parameters (pH, bicarbonate, nitrate, natural organic matter, and solution temperature) indicated that preferred degradation of BrO 3 − occurred in an environment of alkaline pH, low-content natural organic matter/bicarbonate/nitrate, and high natural temperature.
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Rimmer PB, Xu J, Thompson SJ, Gillen E, Sutherland JD, Queloz D. The origin of RNA precursors on exoplanets. SCIENCE ADVANCES 2018; 4:eaar3302. [PMID: 30083602 PMCID: PMC6070314 DOI: 10.1126/sciadv.aar3302] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 06/19/2018] [Indexed: 05/12/2023]
Abstract
Given that the macromolecular building blocks of life were likely produced photochemically in the presence of ultraviolet (UV) light, we identify some general constraints on which stars produce sufficient UV for this photochemistry. We estimate how much light is needed for the UV photochemistry by experimentally measuring the rate constant for the UV chemistry ("light chemistry", needed for prebiotic synthesis) versus the rate constants for the bimolecular reactions that happen in the absence of the UV light ("dark chemistry"). We make these measurements for representative photochemical reactions involving SO 3 2 - and HS-. By balancing the rates for the light and dark chemistry, we delineate the "abiogenesis zones" around stars of different stellar types based on whether their UV fluxes are sufficient for building up this macromolecular prebiotic inventory. We find that the SO 3 2 - light chemistry is rapid enough to build up the prebiotic inventory for stars hotter than K5 (4400 K). We show how the abiogenesis zone overlaps with the liquid water habitable zone. Stars cooler than K5 may also drive the formation of these building blocks if they are very active. The HS- light chemistry is too slow to work even for early Earth.
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Affiliation(s)
- Paul B. Rimmer
- Cavendish Astrophysics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Jianfeng Xu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Samantha J. Thompson
- Cavendish Astrophysics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
| | - Ed Gillen
- Cavendish Astrophysics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
| | - John D. Sutherland
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Didier Queloz
- Cavendish Astrophysics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
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Schaefer T, Herrmann H. Competition kinetics of OH radical reactions with oxygenated organic compounds in aqueous solution: rate constants and internal optical absorption effects. Phys Chem Chem Phys 2018; 20:10939-10948. [PMID: 29623312 DOI: 10.1039/c7cp08571k] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Oxygenated organic compounds are omnipresent in the troposphere, due to their strong emissions from either biogenic or anthropogenic sources. Additionally, the degradation and oxidation processes of volatile organic compounds (VOCs) result in the production of oxygenated organic compounds in the troposphere. The degradation and conversion of these compounds are often initiated by radical reactions and occur in the gas phase as well as in the aqueous phase, including cloud droplets, fog, haze, rain or hygroscopic particles containing 'aerosol liquid water (ALW)'. In the present study, the temperature-dependent OH radical reactions with oxygenated organic compounds in the aqueous phase have been investigated by laser flash photolysis. To determine the rate constants, the OH radical - thiocyanate anion competition kinetics method has been used. Once the organic reactant has an absorption at the excitation wavelength of the photolysis laser, the initial OH concentration decreases. This internal absorption effect leads to an overestimated rate constant of the investigated compound. The present study considers this contribution in order to clarify the internal absorption effect of the investigated organic compounds. The following rate constants for OH radical oxidation reactions of the oxygenated organic compounds have been obtained: acetone (2-propanone) k298K = (7.6 ± 1.0) × 107 L mol-1 s-1, 1-hydroxypropan-2-one k298K = (1.1 ± 0.1) × 109 L mol-1 s-1, 1,3-dihydroxypropan-2-one k298K = (1.5 ± 0.1) × 109 L mol-1 s-1, 2,3-dihydroxypropanal k298K = (1.3 ± 0.1) × 109 L mol-1 s-1, butane-1,3-diol k298K = (2.5 ± 0.1) × 109 L mol-1 s-1, butane-2,3-diol k298K = (2.0 ± 0.1) × 109 L mol-1 s-1 and hexane-1,2-diol k298K = (4.6 ± 0.4) × 109 L mol-1 s-1. With the rate constants obtained and their T-dependencies, the source and sink processes of oxygenated organic compounds in the tropospheric aqueous phase are arrived at precisely. These findings might enhance the predictive capabilities of models such as the chemical aqueous-phase radical mechanism (CAPRAM).
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Affiliation(s)
- T Schaefer
- Leibniz-Institute for Tropospheric Research (TROPOS), Atmospheric Chemistry Department (ACD), Permoserstraße 15, Leipzig 04318, Germany.
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Sun Z, Zhang C, Xing L, Zhou Q, Dong W, Hoffmann MR. UV/Nitrilotriacetic Acid Process as a Novel Strategy for Efficient Photoreductive Degradation of Perfluorooctanesulfonate. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:2953-2962. [PMID: 29397704 DOI: 10.1021/acs.est.7b05912] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Perfluorooctanesulfonate (PFOS) is a toxic, bioaccumulative, and highly persistent anthropogenic chemical. Hydrated electrons ( eaq-) are potent nucleophiles that can effectively decompose PFOS. In previous studies, eaq- are mainly produced by photoionization of aqueous anions or aromatic compounds. In this study, we proposed a new photolytic strategy to generate eaq- and in turn decompose PFOS, which utilizes nitrilotriacetic acid (NTA) as a photosensitizer to induce water photodissociation and photoionization, and subsequently as a scavenger of hydroxyl radical (•OH) to minimize the geminate recombination between •OH and eaq-. The net effect is to increase the amount of eaq- available for PFOS degradation. The UV/NTA process achieved a high PFOS degradation ratio of 85.4% and a defluorination ratio of 46.8% within 10 h. A pseudo-first-order rate constant ( k) of 0.27 h-1 was obtained. The laser flash photolysis study indicates that eaq- is the dominant reactive species responsible for PFOS decomposition. The generation of eaq- is greatly enhanced and its half-life is significantly prolonged in the presence of NTA. The electron spin resonance (ESR) measurement verified the photodissociation of water by detecting •OH. The model compound study indicates that the acetate and amine groups are the primary reactive sites.
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Affiliation(s)
- Zhuyu Sun
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering , Tongji University , Shanghai 200092 , China
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , China
| | - Chaojie Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering , Tongji University , Shanghai 200092 , China
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , China
| | - Lu Xing
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering , Tongji University , Shanghai 200092 , China
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , China
| | - Qi Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering , Tongji University , Shanghai 200092 , China
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , China
| | - Wenbo Dong
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering , Fudan University , Shanghai 200433 , China
| | - Michael R Hoffmann
- Linde-Robinson Laboratories , California Institute of Technology , Pasadena , California 91125 , United States
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Yu K, Li X, Chen L, Fang J, Chen H, Li Q, Chi N, Ma J. Mechanism and efficiency of contaminant reduction by hydrated electron in the sulfite/iodide/UV process. WATER RESEARCH 2018; 129:357-364. [PMID: 29169109 DOI: 10.1016/j.watres.2017.11.030] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 11/08/2017] [Accepted: 11/11/2017] [Indexed: 06/07/2023]
Abstract
Advanced reduction by the extremely strong reducing species, hydrated electron (eaq-), is a promising and viable approach to eliminate a wide variety of persistent and toxic contaminants. In this study, we proposed a sulfite/iodide/UV process, which offered efficient production of eaq- for contaminant reduction. Using monochloroacetic acid (MCAA) as a simple eaq- probe, the availability of eaq- was assessed, and the mechanism involving the roles of S(IV) and iodide in the process was elucidated. A pronounced synergistic effect of S(IV) and iodide was observed in MCAA reductive dechlorination. The efficiency was much more dependent on the iodide concentration due to its higher absorptivity and quantum yield of eaq-. S(IV) played a dual role by producing eaq- via photoionization of SO32- and by reducing the reactive iodine species formed to avoid their scavenging of eaq-. When S(IV) was available, cycling of iodide occurred, favoring the constant eaq- production. The formation and transformation kinetics of sulfite radical were studied to verify the roles of S(IV) and iodide in the process. A kinetic model of MCAA dechlorination was also developed to quantify the eaq--initiated reduction efficiency, highlighting the effects of S(IV), iodide, and pH. High pH favored the reduction, and the process was still effective in field surface water. This study underscores the importance of producing eaq- efficiently and of minimizing the eaq- scavenging of intermediates inherently formed and accumulated, and highlights the potential of the sulfite/iodide/UV process to efficiently eliminate recalcitrant contaminants.
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Affiliation(s)
- Keer Yu
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Xuchun Li
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, China.
| | - Liwei Chen
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Jingyun Fang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China
| | - Huali Chen
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Qiangbiao Li
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Nianping Chi
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
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Tian H, Gu C. Effects of different factors on photodefluorination of perfluorinated compounds by hydrated electrons in organo-montmorillonite system. CHEMOSPHERE 2018; 191:280-287. [PMID: 29040942 DOI: 10.1016/j.chemosphere.2017.10.074] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 09/23/2017] [Accepted: 10/12/2017] [Indexed: 06/07/2023]
Abstract
Perfluorinated compounds (PFCs) are considered as the most recalcitrant organic contaminants. Our previous research has shown that PFCs can be completely defluorinated in the UV/organoclay/3-indole acetic acid system, however, the factors that could affect the degradation of PFCs, are still not clear. In this study, we further investigated the effect of different indole derivatives and organo-modified montmorillonite on the degradation of perfluooctanoic acid (PFOA). Based on multiple linear regression analysis, our results clearly indicate that hydrated electron yields of indole derivatives, adsorption of PFOA and indole derivatives on organo-montmorillonite contributed independently to the degradation of PFOA. In addition, the results also show that the presence of humic substance (even at 10 mg C L-1) would not significantly suppress the degradation process due to the strong adsorption of humic substance on the organo-montmorillonite surface. This study would provide more information to design an efficient and environment-friendly system for degradation of PFCs, and this technique will have great potential for treatment of persistent contaminants under mild reaction conditions.
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Affiliation(s)
- Haoting Tian
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China; Shandong Provincial Key Laboratory of Water and Soil Conservation & Environmental Protection, College of Resource and Environment, Linyi University, Linyi 276005, PR China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
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44
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Sun Z, Zhang C, Chen P, Zhou Q, Hoffmann MR. Impact of humic acid on the photoreductive degradation of perfluorooctane sulfonate (PFOS) by UV/Iodide process. WATER RESEARCH 2017; 127:50-58. [PMID: 29031799 DOI: 10.1016/j.watres.2017.10.010] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 10/03/2017] [Accepted: 10/05/2017] [Indexed: 06/07/2023]
Abstract
Iodide photolysis under UV illumination affords an effective method to produce hydrated electrons (eaq-) in aqueous solution. Therefore, UV/Iodide photolysis can be utilized for the reductive degradation of many recalcitrant pollutants. However, the effect of naturally occurring organic matter (NOM) such as humic and fulvic acids (HA/FA), which may impact the efficiency of UV/Iodide photoreduction, is poorly understood. In this study, the UV photoreductive degradation of perfluorooctane sulfonate (PFOS) in the presence of I- and HA is studied. PFOS undergoes a relatively slow direct photoreduction in pure water, a moderate level of degradation via UV/Iodide, but a rapid degradation via UV/Iodide/HA photolysis. After 1.5 h of photolysis, 86.0% of the initial [PFOS] was degraded in the presence of both I- and HA with a corresponding defluorination ratio of 55.6%, whereas only 51.7% of PFOS was degraded with a defluorination ratio of 4.4% via UV/Iodide illumination in the absence of HA. The relative enhancement in the presence of HA in the photodegradation of PFOS can be attributed to several factors: a) HA enhances the effective generation of eaq- due to the reduction of I2, HOI, IO3- and I3- back to I-; b) certain functional groups of HA (i.e., quinones) enhance the electron transfer efficiency as electron shuttles; c) a weakly-bonded association of I- and PFOS with HA increases the reaction probability; and d) absorption of UV photons by HA itself produces eaq-. The degradation and defluorination efficiency of PFOS by UV/Iodide/HA process is dependent on pH and HA concentration. As pH increases from 7.0 to 10.0, the enhancement effect of HA improves significantly. The optimal HA concentration for the degradation of 0.03 mM PFOS is 1.0 mg L-1.
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Affiliation(s)
- Zhuyu Sun
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Chaojie Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Pei Chen
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Qi Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Michael R Hoffmann
- Linde-Robinson Laboratories, California Institute of Technology, Pasadena, CA 91125, United States
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45
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Banyasz A, Martínez-Fernández L, Balty C, Perron M, Douki T, Improta R, Markovitsi D. Absorption of Low-Energy UV Radiation by Human Telomere G-Quadruplexes Generates Long-Lived Guanine Radical Cations. J Am Chem Soc 2017; 139:10561-10568. [PMID: 28737902 DOI: 10.1021/jacs.7b05931] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Telomeres, which are involved in cell division, carcinogenesis, and aging and constitute important therapeutic targets, are prone to oxidative damage. This propensity has been correlated with the presence of guanine-rich sequences, capable of forming four-stranded DNA structures (G-quadruplexes). Here, we present the first study on oxidative damage of human telomere G-quadruplexes without mediation of external molecules. Our investigation has been performed for G-quadruplexes formed by folding of GGG(TTAGGG)3 single strands in buffered solutions containing Na+ cations (TEL21/Na+). Associating nanosecond time-resolved spectroscopy and quantum mechanical calculations (TD-DFT), it focuses on the primary species, ejected electrons and guanine radicals, generated upon absorption of UV radiation directly by TEL21/Na+. We show that, at 266 nm, corresponding to an energy significantly lower than the guanine ionization potential, the one-photon ionization quantum yield is 4.5 × 10-3. This value is comparable to that of cyclobutane thymine dimers (the major UV-induced lesions) in genomic DNA; the quantum yield of these dimers in TEL21/Na+ is found to be (1.1 ± 0.1) × 10-3. The fate of guanine radicals, generated in equivalent concentration with that of ejected electrons, is followed over 5 orders of magnitude of time. Such a quantitative approach reveals that an important part of radical cation population survives up to a few milliseconds, whereas radical cations produced by chemical oxidants in various DNA systems are known to deprotonate, at most, within a few microseconds. Under the same experimental conditions, neither one-photon ionization nor long-lived radical cations are detected for the telomere repeat TTAGGG in single-stranded configuration, showing that secondary structure plays a key role in these processes. Finally, two types of deprotonated radicals are identified: on the one hand, (G-H2)• radicals, stable at early times, and on the other hand, (G-H1)• radicals, appearing within a few milliseconds and decaying with a time constant of ∼50 ms.
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Affiliation(s)
- Akos Banyasz
- LIDYL, CEA, CNRS, Université Paris-Saclay , F-91191 Gif-sur-Yvette, France
| | - Lara Martínez-Fernández
- Istituto Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche , Via Mezzocannone 16, I-80134 Napoli, Italy
| | - Clémence Balty
- LIDYL, CEA, CNRS, Université Paris-Saclay , F-91191 Gif-sur-Yvette, France
| | - Marion Perron
- LIDYL, CEA, CNRS, Université Paris-Saclay , F-91191 Gif-sur-Yvette, France
| | - Thierry Douki
- CEA, INAC-SyMMES Laboratoire des Lésions des Acides Nucléiques, F-38000 Grenoble, France
| | - Roberto Improta
- LIDYL, CEA, CNRS, Université Paris-Saclay , F-91191 Gif-sur-Yvette, France.,Istituto Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche , Via Mezzocannone 16, I-80134 Napoli, Italy
| | - Dimitra Markovitsi
- LIDYL, CEA, CNRS, Université Paris-Saclay , F-91191 Gif-sur-Yvette, France
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Allard S, Criquet J, Prunier A, Falantin C, Le Person A, Yat-Man Tang J, Croué JP. Photodecomposition of iodinated contrast media and subsequent formation of toxic iodinated moieties during final disinfection with chlorinated oxidants. WATER RESEARCH 2016; 103:453-461. [PMID: 27498253 DOI: 10.1016/j.watres.2016.07.050] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/18/2016] [Accepted: 07/21/2016] [Indexed: 06/06/2023]
Abstract
Large amount of iodinated contrast media (ICM) are found in natural waters (up to μg.L(-)(1) levels) due to their worldwide use in medical imaging and their poor removal by conventional wastewater treatment. Synthetic water samples containing different ICM and natural organic matter (NOM) extracts were subjected to UV254 irradiation followed by the addition of chlorine (HOCl) or chloramine (NH2Cl) to simulate final disinfection. In this study, two new quantum yields were determined for diatrizoic acid (0.071 mol.Einstein(-1)) and iotalamic acid (0.038 mol.Einstein(-1)) while values for iopromide (IOP) (0.039 mol.Einstein(-1)), iopamidol (0.034 mol.Einstein(-1)) and iohexol (0.041 mol.Einstein(-1)) were consistent with published data. The photodegradation of IOP led to an increasing release of iodide with increasing UV doses. Iodide is oxidized to hypoiodous acid (HOI) either by HOCl or NH2Cl. In presence of NOM, the addition of oxidant increased the formation of iodinated disinfection by-products (I-DBPs). On one hand, when the concentration of HOCl was increased, the formation of I-DBPs decreased since HOI was converted to iodate. On the other hand, when NH2Cl was used the formation of I-DBPs was constant for all concentration since HOI reacted only with NOM to form I-DBPs. Increasing the NOM concentration has two effects, it decreased the photodegradation of IOP by screening effect but it increased the number of reactive sites available for reaction with HOI. For experiments carried out with HOCl, increasing the NOM concentration led to a lower formation of I-DBPs since less IOP are photodegraded and iodate are formed. For NH2Cl the lower photodegradation of IOP is compensated by the higher amount of NOM reactive sites, therefore, I-DBPs concentrations were constant for all NOM concentrations. 7 different NOM extracts were tested and almost no differences in IOP degradation and I-DBPs formation was observed. Similar behaviour was observed for the 5 ICM tested. Both oxidant poorly degraded the ICM and a higher formation of I-DBPs was observed for the chloramination experiments compared to the chlorination experiment. Results from toxicity testing showed that the photodegradation products of IOP are toxic and confirmed that the formation of I-DBPs leads to higher toxicity. Therefore, for the experiment with HOCl where iodate are formed the toxicity was lower than for the experiments with NH2Cl where a high formation of I-DBPs was observed.
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Affiliation(s)
- Sébastien Allard
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
| | - Justine Criquet
- Université Lille 1 Sciences and Technologies, LASIR, UMR CNRS 8516, 59655 Villeneuve d'Ascq, France
| | - Anaïs Prunier
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University, GPO Box U1987, Perth, WA 6845, Australia
| | - Cécilia Falantin
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University, GPO Box U1987, Perth, WA 6845, Australia; Université Lille 1 Sciences and Technologies, LASIR, UMR CNRS 8516, 59655 Villeneuve d'Ascq, France
| | - Annaïg Le Person
- Université Lille 1 Sciences and Technologies, LASIR, UMR CNRS 8516, 59655 Villeneuve d'Ascq, France
| | - Janet Yat-Man Tang
- National Research Centre for Environmental Toxicology (Entox), The University of Queensland, Brisbane, QLD 4108, Australia
| | - Jean-Philippe Croué
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University, GPO Box U1987, Perth, WA 6845, Australia
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Li X, Fang J, Liu G, Zhang S, Pan B, Ma J. Kinetics and efficiency of the hydrated electron-induced dehalogenation by the sulfite/UV process. WATER RESEARCH 2014; 62:220-228. [PMID: 24956604 DOI: 10.1016/j.watres.2014.05.051] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 05/21/2014] [Accepted: 05/26/2014] [Indexed: 06/03/2023]
Abstract
Hydrated electron (e(aq)(-)), which is listed among the most reactive reducing species, has great potential for removal and detoxification of recalcitrant contaminants. Here we provided quantitative insight into the availability and conversion of e(aq)(-) in a newly developed sulfite/UV process. Using monochloroacetic acid as a simple e(aq)(-)-probe, the e(aq)(-)-induced dehalogenation kinetics in synthetic and surface water was well predicted by the developed models. The models interpreted the complex roles of pH and S(IV), and also revealed the positive effects of UV intensity and temperature quantitatively. Impacts of humic acid, ferrous ion, carbonate/bicarbonate, and surface water matrix were also examined. Despite the retardation of dehalogenation by electron scavengers, the process was effective even in surface water. Efficiency of the process was discussed, and the optimization approaches were proposed. This study is believed to better understand the e(aq)(-)-induced dehalogenation by the sulfite/UV process in a quantitative manner, which is very important for its potential application in water treatment.
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Affiliation(s)
- Xuchun Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Jingyun Fang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Guifang Liu
- School of Civil Engineering, Harbin Engineering University, Harbin 150001, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Bingcai Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
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Christianson JR, Zhu D, Hamers RJ, Schmidt JR. Mechanism of N2 Reduction to NH3 by Aqueous Solvated Electrons. J Phys Chem B 2013; 118:195-203. [DOI: 10.1021/jp406535p] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jeffrey R. Christianson
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Di Zhu
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Robert J. Hamers
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - J. R. Schmidt
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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Shkrob IA, Marin TW, Crowell RA, Wishart JF. Photo- and Radiation-Chemistry of Halide Anions in Ionic Liquids. J Phys Chem A 2013; 117:5742-56. [DOI: 10.1021/jp4042793] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ilya A. Shkrob
- Chemical Sciences and Engineering
Division, Argonne National Laboratory,
9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Timothy W. Marin
- Chemical Sciences and Engineering
Division, Argonne National Laboratory,
9700 South Cass Avenue, Argonne, Illinois 60439, United States
- Chemistry Department, Benedictine University, 5700 College Road, Lisle, Illinois
60532, United States
| | - R. A. Crowell
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | - James F. Wishart
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
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