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Zheng D, Duan J, Wu Y, Dong W. Mechanistic insight into the photoconversion of losartan potassium mediated by different types of microplastics. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:135143. [PMID: 39018600 DOI: 10.1016/j.jhazmat.2024.135143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 06/22/2024] [Accepted: 07/06/2024] [Indexed: 07/19/2024]
Abstract
Nowadays the proliferation of microplastics (MPs) in aquatic environments and impacts on the fate of organic contaminants (OCs) has drawn sustained worldwide attention. In this study, we investigated the effects of different types and aging degrees of MPs, specifically polystyrene (PSMPs), polyethylene terephthalate (PETMPs), and polylactic acid (PLAMPs), on the photo-transformation of LSTPs. Our results revealed that the facilitation of LSTP photoconversion by PSMPs exhibited a positive linear relationship with aging degree. On the other hand, the effects of PETMPs with different oxidation levels on LSTP photoconversion were weak, while the contribution of PLAMPs decreased as aging increased. Characterizations, quenching and probing experiments showed the aging mechanisms and the generation of reactive oxygen species (ROS) converged among various MPs. Specifically, theoretical calculations, TOC and GC-MS were conducted to verify that in the PLA0-mediated systems, it was the intermediates of PLA0 that prevailed in promoting the photoconversion of LSTP. The aged PLA own have a large propensity to consume ROS, which diminished their promotion of LSTP degradation. This differd from the reactions involving PSMPs and PETMPs, where the microplastic particles themselves were the main drivers of the photoconversion process rather than intermediates.
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Affiliation(s)
- Danqing Zheng
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China
| | - Jiehan Duan
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China
| | - Yanlin Wu
- School of Resources and Environmental Engineering, Shanghai Polytechnic University, Shanghai 201209, China.
| | - Wenbo Dong
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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2
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Chen X, Wang Y, Fan X, Zhu G, Liu Y, Quan X. Efficient electro-Fenton degradation of organic pollutants via the synergistic effect of 1O 2 and •OH generated on single FeN 4 sites. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 932:173042. [PMID: 38723975 DOI: 10.1016/j.scitotenv.2024.173042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/05/2024] [Accepted: 05/05/2024] [Indexed: 05/12/2024]
Abstract
The electro-Fenton with in situ generated 1O2 and •OH is a promising method for the degradation of micropollutants. However, its application is hindered by the lack of catalysts that can efficiently generate 1O2 and •OH from electrochemical oxygen reduction. Herein, N-doped stacked carbon nanosheets supported Fe single atoms (Fe-NSC) with FeN4 sites were designed for simultaneous generation of 1O2 and •OH to enhance electro-Fenton degradation. Due to the synergistic effect of 1O2 and •OH, a variety of contaminants (phenol, 2,4-dichlorophenol, sulfamethoxazole, atrazine and bisphenol A) were efficiently degraded with high kinetic constants of 0.037-0.071 min-1 by the electro-Fenton with Fe-NSC as cathode (-0.6 V vs Ag/AgCl, pH 6). Moreover, the superior performance for electro-Fenton degradation was well maintained in a wide pH range from 3 to 10 even with interference of various inorganic salt ions. It was found that FeN4 sites with pyridinic N coordination were responsible for its good performance for electro-Fenton degradation. Its 1O2 yield was higher than •OH yield, and the contribution of 1O2 was more significant than •OH for pollutant degradation.
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Affiliation(s)
- Xin Chen
- 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
| | - Yaqi 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
| | - Xinfei Fan
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Genwang 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
| | - Yanming Liu
- 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.
| | - Xie Quan
- 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
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3
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Lalas K, Arvaniti OS, Panagopoulou EI, Thomaidis NS, Mantzavinos D, Frontistis Z. Acesulfame degradation by thermally activated persulfate: Kinetics, transformation products and estimated toxicity. CHEMOSPHERE 2024; 352:141260. [PMID: 38272137 DOI: 10.1016/j.chemosphere.2024.141260] [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: 09/04/2023] [Revised: 12/27/2023] [Accepted: 01/17/2024] [Indexed: 01/27/2024]
Abstract
The existence of the artificial sweetener acesulfame (ACE) in quantities of significance can negatively impact water quality, and its consumption has been associated with deleterious health effects. The present investigation explores the efficacy of heat-activated sodium persulfate (SPS) for eliminating ACE. The complete degradation of 0.50 mg L-1 of ACE was achieved within 45 min under a reaction temperature of 50 °C and 100 mg L-1 of SPS. The impact of thermal decomposition on ACE at a temperature of 60 °C was negligible. This study considers several factors, such as the SPS and ACE loading, the reaction temperature, the initial pH, and the water matrix of the reactor. The results indicate that the method's efficiency is positively correlated with higher initial concentrations of SPS, whereas it is inversely associated with the initial concentration of ACE. Furthermore, higher reaction temperatures and acidic initial pH levels promote the degradation of acesulfame. At the same time, certain constituents of the water matrix, such as humic acid, chlorides, and bicarbonates, can hinder the degradation process. Additionally, the data from LC-QToF-MS analysis of the samples were used to investigate transformation through suspect and non-target screening approaches. Overall, ACE's eight transformation products (TPs) were detected, and a potential ACE decomposition pathway was proposed. The concentration of TPs followed a volcano curve, decreasing in long treatment times. The ecotoxicity of ACE and its identified TPs was predicted using the ECOSAR software. The majority of TPs exhibited not harmful values.
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Affiliation(s)
- Kosmas Lalas
- Department of Chemical Engineering, University of Western Macedonia, GR-50132, Kozani, Greece
| | - Olga S Arvaniti
- Department of Agricultural Development, Agrofood and Management of Natural Resources, National and Kapodistrian University of Athens, Psachna, GR-34400, Greece
| | - Eleni I Panagopoulou
- Department of Chemistry, Laboratory of Analytical Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, GR 15771, Athens, Greece
| | - Nikolaos S Thomaidis
- Department of Chemistry, Laboratory of Analytical Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, GR 15771, Athens, Greece
| | - Dionissios Mantzavinos
- Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, GR-26504, Patras, Greece
| | - Zacharias Frontistis
- Department of Chemical Engineering, University of Western Macedonia, GR-50132, Kozani, Greece.
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Estrada-Flórez SE, Serna-Galvis EA, Lee J, Torres-Palma RA. Unraveling kinetic and synergistic effects during ultrasound-enhanced carbocatalysis for water remediation as a function of ultrasonic frequency. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 350:119548. [PMID: 38007926 DOI: 10.1016/j.jenvman.2023.119548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/15/2023] [Accepted: 11/04/2023] [Indexed: 11/28/2023]
Abstract
The ability of the ultrasound (US) combined with peroxymonosulfate (PMS), and a carbonaceous material (BC) was evaluated in the degradation of a model pollutant (acetaminophen, ACE). The US/BC/PMS system was compared with other possible systems (US, oxidation by PMS, BC adsorption, BC/PMS, US/PMS, and US/BC. The effect of the ultrasonic frequency (40, 375, and 1135 kHz) on the kinetics and synergy of the ACE removal was evaluated. In the US system, kinetics was favored at 375 kHz due to the increased production of hydroxyl radicals (HO•), but this did not improve in the US/PMS and US/BC systems. However, synergistic and antagonistic effects were observed at the low and high frequencies where the production of radicals is less efficient but there is an activation of PMS through mechanical effects. US/BC/PMS at 40 kHz was the most efficient system obtaining ∼95% ACE removal (40 μM) in the first 10 min of treatment, and high synergy (S = 10.30). This was promoted by disaggregation of the carbonaceous material, increasing the availability of catalytic sites where PMS is activated. The coexistence of free-radical and non-radical pathways was analyzed. Singlet oxygen (1O2) played the dominant role in degradation, while HO• and sulfate radicals (SO4•-), scarcely generated at low frequency, play a minimum role. Performance in hospital wastewater (HWW), urine, and seawater (SW) evidenced the competition of organic matter by BC active sites and reactive species and the removal enhancement when Cl- is present. Besides, toxicity decreased by ∼20% after treatment, being the system effective after three cycles of reuse.
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Affiliation(s)
- Sandra E Estrada-Flórez
- Grupo de Investigación en Remediación Ambiental y Biocatálisis (GIRAB), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Efraím A Serna-Galvis
- Grupo de Investigación en Remediación Ambiental y Biocatálisis (GIRAB), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia; Grupo de Catalizadores y Adsorbentes (CATALAD), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia.
| | - Judy Lee
- School of Chemistry and Chemical Engineering, University of Surrey, Guildford, GU27XH, United Kingdom
| | - Ricardo A Torres-Palma
- Grupo de Investigación en Remediación Ambiental y Biocatálisis (GIRAB), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia.
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Estrada-Flórez SE, Serna-Galvis EA, Lee J, Torres-Palma RA. Systematic study of the synergistic and kinetics effects on the removal of contaminants of emerging concern from water by ultrasound in the presence of diverse oxidants. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-29189-y. [PMID: 37632616 DOI: 10.1007/s11356-023-29189-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 08/01/2023] [Indexed: 08/28/2023]
Abstract
The enhancement of the ultrasound system by adding diverse oxidants to remove a model contaminant (acetaminophen, ACE) in water was investigated. Different parameters were evaluated to study their effect on both the degradation kinetics and the synergy of the combination. The variables studied were the ultrasonic frequency (575, 858, and 1135 kHz), type of oxidant (hydrogen peroxide, sodium peroxydisulfate (or persulfate, PDS), and potassium peroxymonosulfate (PMS)), ACE concentration (4, 8, and 40 µM), and oxidant concentration (0.01, 0.1, 1, and 5 mM). Particular interest was placed on synergistic effects, implying that one process (or both) is activated by the other to lead to greater efficiency. Interestingly, the parameters that led to the higher synergistic effects did not always lead to the most favorable degradation kinetics. An increase in ACE removal of 20% was obtained using the highest frequency studied (1135 kHz), PMS 0.1 mM, and the highest concentration of ACE (40 µM). The intensification of degradation was mainly due to the ability of ultrasound to activate oxidants and produce extra hydroxyl radicals (HO•) or sulfate radicals (SO4•-). Under these conditions, treatment of ACE spiked into seawater, hospital wastewater, and urine was performed. The hospital wastewater matrix inhibited ACE degradation slightly, while the urine components inhibited the pollutant degradation completely. The inhibition was mainly attributed to the competing organic matter in the effluents for the sono-generated radical species. On the contrary, the removal of ACE in seawater was significantly intensified due to "salting out" effects and the production of the strong oxidant HOCl from the reaction of chloride ions with PMS.
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Affiliation(s)
- Sandra E Estrada-Flórez
- Grupo de Investigación en Remediación Ambiental y Biocatálisis (GIRAB), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Efraím A Serna-Galvis
- Grupo de Investigación en Remediación Ambiental y Biocatálisis (GIRAB), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
- Grupo de Catalizadores y Adsorbentes (CATALAD), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Judy Lee
- School of Chemistry and Chemical Engineering, University of Surrey, Guildford, GU2 7XH, United Kingdom
| | - Ricardo A Torres-Palma
- Grupo de Investigación en Remediación Ambiental y Biocatálisis (GIRAB), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia.
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6
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Ding C, Cai Z, Hu C, Lei J, Wang L, Li Q, Li X, Deng J. Degradation of antiviral drug acyclovir by thermal activated persulfate process: Kinetics study and modeling. CHEMOSPHERE 2023; 323:138247. [PMID: 36842560 DOI: 10.1016/j.chemosphere.2023.138247] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/31/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Pharmaceutical and personal care products (PPCPs) pose a great threat to water environment security. In this study, acyclovir (ACV) was efficiently degraded by thermally activated persulfate (TAP) system. The ACV degradation increased with rising reaction temperature and persulfate dosage. With the existence of inorganic anions and humic acid, ACV removal was retarded to varying degrees. Under strong alkaline condition, it was observed that the degradation of ACV was significantly inhibited. In addition, Kintecus software was employed to simulate ACV removal and achieved a good fit with the experimental results. The contribution rates of main reactive radicals under acidic, neutral, and alkaline conditions were investigated, and the contribution of hydroxyl radical (⋅OH) increased significantly under alkaline condition. The main active species were identified as sulfate radical (SO4⋅-) and ⋅OH through quenching experiment, and the second-order reaction rate constants of SO4⋅- and ∙OH reacted with ACV were calculated to be 9.17 × 109 M-1 s-1 and 2.74 × 109 M-1 s-1, respectively. The main degradation pathways included addition of free radicals, oxidation of branch chain and ring opening. The acute and chronic toxicity of intermediates to organisms predicted by ECOSAR were significantly reduced compared with that of ACV.
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Affiliation(s)
- Chunsheng Ding
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Zhiyue Cai
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Chenkai Hu
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Jia Lei
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Lei Wang
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Qingsong Li
- Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen 361005, China
| | - Xueyan Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Jing Deng
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China.
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Dhawle R, Giannakopoulos S, Frontistis Z, Mantzavinos D. Peroxymonosulfate Enhanced Photoelectrocatalytic Degradation Of 17α-Ethinyl Estradiol. Catal Today 2023. [DOI: 10.1016/j.cattod.2023.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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8
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Photo-Fenton and Electro-Fenton Performance for the Removal of Pharmaceutical Compounds in Real Urban Wastewater. Electrochim Acta 2023. [DOI: 10.1016/j.electacta.2023.141905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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9
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Kanafin YN, Abdirova P, Arkhangelsky E, Dionysiou DD, Poulopoulos SG. UVA and goethite activated persulfate oxidation of landfill leachate. CHEMICAL ENGINEERING JOURNAL ADVANCES 2023. [DOI: 10.1016/j.ceja.2023.100452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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10
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Li L, Zheng D, Gu X, Sun C, Liu Y, Dong W, Wu Y. Mechanism of the improved Fe(III)/persulfate reaction by gallic acid for ibuprofen degradation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 314:120318. [PMID: 36183876 DOI: 10.1016/j.envpol.2022.120318] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 09/24/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
Gallic acid (GA), a natural plant polyphenol, was applied as amendment of Fe(III)/persulfate (PS) system for ibuprofen (IBP) degradation in this study. The impacts of all agentia (GA, Fe(III), PS) concentration and initial pH values on IBP removal efficiency were investigated, and their corresponding observed pseudo-first-order rate constants (kobs) were calculated. The addition of GA has significantly improved elimination efficiency of IBP due to the enhanced Fe(III)/Fe(II) cycle. Electron paramagnetic resonance (EPR) results confirmed that SO4•-, HO• and O2•- were involved in GA/Fe(III)/PS system. However, quenching experiments further affirmed the impact of SO4•- and HO• towards IBP decomposition instead of O2•-, with contribution ratio to IBP removal was 69.12% and 30.88%, respectively. SO4•- was the main radicals formed by directly activation of PS with Fe(II), while HO• was the transformation product of SO4•-. Based on instrumental analysis (stopped-flow UV-vis spectrum and MS) and theoretical calculation, the potential reaction mechanism between GA and Fe(III) in the presence of PS was further proposed. GA complexed with Fe(III) firstly and the Fe(III)-GA complex was then converted into quinone substance, accompanied by the generation of Fe(II). Furthermore, the application of GA extended the optimal pH range to neutral as well, which made it a promising treatment in practical application.
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Affiliation(s)
- Linyi Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China
| | - Danqing Zheng
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China
| | - Xinyi Gu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China
| | - Chengju Sun
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China
| | - Yankun Liu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China
| | - Wenbo Dong
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China
| | - Yanlin Wu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China.
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11
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Lalas K, Arvaniti OS, Zkeri E, Nika MC, Thomaidis NS, Mantzavinos D, Stasinakis AS, Frontistis Z. Thermally activated persulfate oxidation of ampicillin: Kinetics, transformation products and ecotoxicity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 846:157378. [PMID: 35843320 DOI: 10.1016/j.scitotenv.2022.157378] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 07/10/2022] [Accepted: 07/10/2022] [Indexed: 06/15/2023]
Abstract
The heat-activated persulfate system showed encouraging results for the destruction of the widely used antibiotic Ampicillin (AMP). AMP removal follows exponential decay, and the observed kinetic constant was enhanced with persulfate (PS) dosage at the range 50-500 mg L-1 and temperature (40-60 °C), while AMP thermolysis at 60 °C was almost negligible. The apparent activation energy was estimated to 124.7 kJ mol-1. Alkaline conditions, water matrix constituents like bicarbonates, humic acid, and real water matrices retarded AMP oxidation. Experiments performed with tert-butanol and methanol as scavengers demonstrated the contribution of sulfate radicals as the dominant reactive species. Seven transformation products (TPs) of AMP have been identified from AMP destruction. An EC50 value equal to 187 mg L-1 was calculated for 72 h of exposure of the microalgae Chlorella sorokiniana to AMP. According to the ecotoxicity experiments that conducted after treatment of AMP with PS for different reaction times, no important inhibition of microalgae was noticed for contact time of 72 h and 10 d. These results indicate the formation of no toxic AMP by-products for the applied experimental conditions.
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Affiliation(s)
- Kosmas Lalas
- Department of Chemical Engineering, University of Western Macedonia, GR 50132 Kozani, Greece
| | - Olga S Arvaniti
- Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, GR 26504 Patras, Greece; Department of Agricultural Development, Agrofood and Management of Natural Resources, National and Kapodistrian University of Athens, Psachna 34400, Greece
| | - Eirini Zkeri
- Department of Environment, University of the Aegean, GR 81100 Mytilene, Greece
| | - Maria-Christina Nika
- Department of Chemistry, Laboratory of Analytical Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, GR 15771 Athens, Greece
| | - Nikolaos S Thomaidis
- Department of Chemistry, Laboratory of Analytical Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, GR 15771 Athens, Greece
| | - Dionissios Mantzavinos
- Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, GR 26504 Patras, Greece
| | | | - Zacharias Frontistis
- Department of Chemical Engineering, University of Western Macedonia, GR 50132 Kozani, Greece.
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12
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Pandya K, T S AS, Kodgire P, Simon S. Combined ultrasound cavitation and persulfate for the treatment of pharmaceutical wastewater. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 86:2157-2174. [PMID: 36378172 DOI: 10.2166/wst.2022.304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In recent years industrialization has caused magnificent leaps in the high profitable growth of pharmaceutical industries, and simultaneously given rise to environmental pollution. Pharmaceutical processes like extraction, purification, formulation, etc., generate a large volume of wastewater that contains high chemical oxygen demand (COD), biological oxygen demand, auxiliary chemicals, and different pharmaceutical substances or their metabolites in their active or inactive form. Its metabolites impart non-biodegradable toxic pollutants as a byproduct and intense color, which increases ecotoxicity into the water, thus this requires proper treatment before being discharged. This study focuses on the feasibility analysis of the utilization of ultrasound cavitation (20 kHz frequency) together with a persulfate oxidation approach for the treatment of complex pharmaceutical effluent. Process parameters like pH, amplitude intensity, oxidant dosage were optimized for COD removal applying response surface methodology-based Box-Behnken design. The optimum value observed for pH, amplitude intensity and oxidant dosage are 5, 20% and 100 mg/L respectively with 39.5% removal of COD in 60 min of fixed processing time. This study confirms that a combination of ultrasound cavitation and persulfate is a viable option for the treatment of pharmaceutical wastewater and can be used as an intensification technology in existing effluent treatment plants to achieve the highest amount of COD removal.
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Affiliation(s)
- Karan Pandya
- Department of Civil Engineering, School of Technology, Pandit Deendayal Energy University, Gandhinagar, Gujarat, India E-mail:
| | - Anantha Singh T S
- Department of Civil Engineering, School of Technology, Pandit Deendayal Energy University, Gandhinagar, Gujarat, India E-mail: ; Department of Civil Engineering, National Institute of Technology Calicut, Calicut, India
| | - Pravin Kodgire
- Department of Chemical Engineering, School of Technology, Pandit Deendayal Energy University, Gandhinagar, Gujarat, India
| | - Saji Simon
- Department of Civil Engineering, National Institute of Technology Calicut, Calicut, India
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13
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Tailoring the Biochar Physicochemical Properties Using a Friendly Eco-Method and Its Application on the Oxidation of the Drug Losartan through Persulfate Activation. Catalysts 2022. [DOI: 10.3390/catal12101245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study, spent malt rootlet-derived biochar was modified by a friendly eco-method using a low temperature (100 °C) and dilute acid, base, or water. The modification significantly enhanced the surface area from 100 to 308–428 m2g−1 and changed the morphology and the carbon phase. In addition, the mineral’s percentage and zero-point charge were significantly affected. Among the examined materials, the acid-treated biochar exhibited higher degradation of the drug losartan in the presence of persulfate. Interestingly, the biochar acted as an adsorbent at pH 3, whereas at pH = 5.6 and 10, the apparent kinetic constant’s ratio koxidation/kadsorption was 3.73 ± 0.03, demonstrating losartan oxidation. Scavenging experiments indirectly demonstrated that the role of the non-radical mechanism (singlet oxygen) was crucial; however, sulfate and hydroxyl radicals also significantly participated in the oxidation of losartan. Experiments in secondary effluent resulted in decreased efficiency in comparison to pure water; this is ascribed to the competition between the actual water matrix constituents and the target compound for the active biochar sites and reactive species.
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14
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Kalogerakis GC, Boparai HK, Sleep BE. The journey of toluene to complete mineralization via heat-activated peroxydisulfate in water: intermediates analyses, CO 2 monitoring, and carbon mass balance. JOURNAL OF HAZARDOUS MATERIALS 2022; 440:129739. [PMID: 35986942 DOI: 10.1016/j.jhazmat.2022.129739] [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: 05/30/2022] [Revised: 07/22/2022] [Accepted: 08/07/2022] [Indexed: 06/15/2023]
Abstract
Our study has thoroughly investigated the complete mineralization of toluene in water via heat-activated peroxydisulfate (PDS) by: (1) monitoring concentrations/peak areas of various intermediates and CO2 throughout the reaction period and (2) identifying water-soluble and methanol-soluble intermediates, including trimers, dimers, and organo-sulfur compounds, via non-target screening using high-resolution mass spectrometry. Increased temperature and PDS dosage enhanced toluene removal/mineralization kinetics and increased the rate/extent of benzaldehyde formation and its further transformation. Artificial groundwater and phosphate buffer minimally impacted toluene removal but significantly decreased benzaldehyde formation, indicating a shift in transformation pathways. The stoichiometric PDS dose (18 mM at 40 °C) was adequate to completely mineralize toluene (1 mM), with < 10% PDS needed to transform toluene to intermediates. Toluene transformation to intermediates occurred in 47 h (kobs,toluene = 0.594 h-1) whereas 564 h were required for complete mineralization (kobs,CO2 = 0.0038 h-1). O2 accumulated once mineralization neared completion. A carbon mass balance, including quantification of nine intermediates and CO2 throughout the transformation period, showed that unquantified/unknown intermediates (including yellowish-white precipitates) reached as high as 80% of total carbon before transformation to CO2. Possible toluene transformation pathways via hydroxylation, sulfate addition, and oxidative coupling are proposed.
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Affiliation(s)
- Georgina C Kalogerakis
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto M5S 1A4, ON, Canada
| | - Hardiljeet K Boparai
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto M5S 1A4, ON, Canada
| | - Brent E Sleep
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto M5S 1A4, ON, Canada.
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Arvaniti OS, Ioannidi AA, Mantzavinos D, Frontistis Z. Heat-activated persulfate for the degradation of micropollutants in water: A comprehensive review and future perspectives. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 318:115568. [PMID: 35777153 DOI: 10.1016/j.jenvman.2022.115568] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 06/12/2022] [Accepted: 06/17/2022] [Indexed: 06/15/2023]
Abstract
This work is a critical review of the most important studies that have dealt with heat-activated persulfate to degrade persistent micropollutants in the last six years. The effect of the different operating parameters is discussed, wherein in all cases, the efficiency was favored at higher temperatures and oxidant concentrations. Particular emphasis was given to the effect of the aqueous matrix. Since heat activation is a homogeneous process based on the production of free radicals, in most of the studies presented, the removal of pollutants decreases as the complexity of the aqueous matrix increases except in cases where secondary oxidative species are produced that are selective with specific pollutants. It has also been observed that the change in toxicity usually follows the removal of the parent compound despite the formation of several by-products. Nowadays, combining different processes for the simultaneous activation of persulfate seems to be gaining ground. A hybrid process is an interesting strategy to reduce costs and increase efficiency, especially in real wastewater. In this light, the most interesting studies of hybrid systems for the destruction of micropollutants in recent years based on thermally activated persulfate are also summarized. Finally, some steps are proposed for future research towards the industrial application, including the study of chemical mixtures, the integrated toxicity assessment, the examination of simultaneous disinfection and decomposition of pollutants into real wastewater, the estimation of the required costs, and energy the combination of processes and their coupling with renewable sources, and the design of pilot plants and the scale-up of the hybrid processes.
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Affiliation(s)
- Olga S Arvaniti
- Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, GR, 26504, Patras, Greece
| | - Alexandra A Ioannidi
- Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, GR, 26504, Patras, Greece
| | - Dionissios Mantzavinos
- Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, GR, 26504, Patras, Greece
| | - Zacharias Frontistis
- Department of Chemical Engineering, University of Western Macedonia, GR, 50132, Kozani, Greece.
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16
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Arvaniti OS, Antonopoulou G, Gatidou G, Frontistis Z, Mantzavinos D, Stasinakis AS. Sorption of two common antihypertensive drugs onto polystyrene microplastics in water matrices. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 837:155786. [PMID: 35537511 DOI: 10.1016/j.scitotenv.2022.155786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/20/2022] [Accepted: 05/04/2022] [Indexed: 06/14/2023]
Abstract
Recent studies have shown the widespread occurrence of microplastics in multiple environmental compartments. When discharged into the aquatic environment, microplastics interact with other chemicals acting as vectors of organic and inorganic micropollutants. In the present study, we examined the sorption of two commonly used antihypertensive drugs, valsartan (VAL) and losartan (LOS), onto polystyrene (PS) microplastics and we studied the effects of water matrix, solution's pH, salinity, and microplastics' aging on their sorption. According to the results, the sorption of VAL and LOS onto PS is a slow process that reaches equilibrium after 12 days. The sorption of both target micropollutants was pH-dependent and significantly decreased under alkaline conditions. The removal of VAL was enhanced in the presence of 100 mM of Ca2+ while no statistical significant effects were observed when Na+ was added. The increase of salinity either did not affect or decreased the removal of LOS. Lower sorption of both drugs was observed when aged PS was used despite that the specific surface area for aged PS was 39% higher than pristine. Calculation of the sorption distribution coefficient (Kd) for different water matrices showed that the increase of matrix complexity inhibited target compounds' removal and the sorption rate decreased from bottled water > river water ≈ treated wastewater for the two compounds. For VAL, the Kd values ranged between 795 ± 63 L/kg (bottled water) and 384 ± 88 L/kg (river water), while for LOS between 4453 ± 417 L/kg (bottled water) and 3078 ± 716 L/kg (treated wastewater). Both VAL and LOS sorption onto PS microplastics can be described by hydrophobic and electrostatic interactions. The current results indicate that PS particles could affect the transportation of antihypertensive drugs in the aquatic environment causing potential adverse effects on the environment and public health.
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Affiliation(s)
- Olga S Arvaniti
- Water and Air Quality Laboratory, Department of Environment, University of the Aegean, Mytilene 81100, Greece; Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, Patras 26504, Greece; Department of Agricultural Development, Agrofood and Management of Natural Resources, National and Kapodistrian University of Athens, Psachna 34400, Greece
| | - Georgia Antonopoulou
- Water and Air Quality Laboratory, Department of Environment, University of the Aegean, Mytilene 81100, Greece; Institute of Chemical Engineering Sciences, 11 Stadiou St., Platani, Patras 26504, Greece
| | - Georgia Gatidou
- Water and Air Quality Laboratory, Department of Environment, University of the Aegean, Mytilene 81100, Greece
| | - Zacharias Frontistis
- Department of Chemical Engineering, University of Western Macedonia, GR-50132 Kozani, Greece
| | - Dionissios Mantzavinos
- Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, Patras 26504, Greece
| | - Athanasios S Stasinakis
- Water and Air Quality Laboratory, Department of Environment, University of the Aegean, Mytilene 81100, Greece.
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Thermally activated persulfate-based Advanced Oxidation Processes — recent progress and challenges in mineralization of persistent organic chemicals: a review. Curr Opin Chem Eng 2022. [DOI: 10.1016/j.coche.2022.100839] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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18
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Tisler S, Engler N, Jørgensen MB, Kilpinen K, Tomasi G, Christensen JH. From data to reliable conclusions: Identification and comparison of persistent micropollutants and transformation products in 37 wastewater samples by non-target screening prioritization. WATER RESEARCH 2022; 219:118599. [PMID: 35598471 DOI: 10.1016/j.watres.2022.118599] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 05/04/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
In this study, micropollutants in wastewater effluents were prioritized by monitoring the composition of influent and effluent wastewater by liquid chromatography - high-resolution mass spectrometry (LCHRMS) non-target screening (NTS) analysis. The study shows how important data pre-processing and filtering of raw data is to produce reliable NTS data for comparison of compounds between many samples (37 wastewater samples) analyzed at different times. Triplicate injections were critical for reducing the number of false-positive detections. Intensity drift corrections within and between batches analyzed months apart made peak intensities comparable across samples. Adjustment of the feature detection threshold was shown to be important, due to large intensity variations for low abundance compounds across batches. When the threshold correction cut-offs, or the filtering of relevant compounds by the occurrence frequency, were too stringent, a high number of false positive transformation products (TPs) were reported. We also showed that matrix effect correction by internal standards can over- or under-correct the intensity for unknown compounds, thus the TIC matrix effect correction was shown as an additional tool for a retention time dependent matrix effect correction. After these preprocessing and filtering steps, we identified 78 prioritized compounds, of which 36 were persistent compounds, defined as compounds with a reduction in peak intensity between influent and effluent wastewater <50%, and 13 compounds were defined as TPs because they occurred solely in the effluent samples. Some examples of persistent compounds are 1,3-diphenylguanidine, amisulpride and the human metabolites from losartan, verapamil and methadone. To our knowledge, nine of the identified TPs have not been previously described in effluent wastewater. The TPs were derived from metoprolol, fexofenadine, DEET and losartan. The screening of all identified compounds in effluent samples from eight wastewater treatment plants (WWTPs) showed that potential drugs of abuse, anti-psychotic and anti-depressant drugs were predominant in the capital city region, whereas the anti-epileptic agents and agricultural pesticides were dominant in more rural areas.
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Affiliation(s)
- Selina Tisler
- Analytical Chemistry Group, Department of Plant and Environmental Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, 1871, Denmark.
| | - Nikolina Engler
- Analytical Chemistry Group, Department of Plant and Environmental Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, 1871, Denmark
| | | | - Kristoffer Kilpinen
- Analytical Chemistry Group, Department of Plant and Environmental Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, 1871, Denmark; Eurofins Miljø Denmark A/S, Ladelundvej 85, Vejen 6600, Denmark
| | - Giorgio Tomasi
- Analytical Chemistry Group, Department of Plant and Environmental Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, 1871, Denmark
| | - Jan H Christensen
- Analytical Chemistry Group, Department of Plant and Environmental Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, 1871, Denmark
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Giannakopoulos S, Frontistis Z, Vakros J, Poulopoulos SG, Manariotis ID, Mantzavinos D. Combined activation of persulfate by biochars and artificial light for the degradation of sulfamethoxazole in aqueous matrices. J Taiwan Inst Chem Eng 2022. [DOI: 10.1016/j.jtice.2022.104440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Biswas P, Vellanki BP, Kazmi AA. Investigating a broad range of emerging contaminants in a set of anthropogenically impacted environmental compartments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 824:153757. [PMID: 35151754 DOI: 10.1016/j.scitotenv.2022.153757] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/01/2022] [Accepted: 02/05/2022] [Indexed: 06/14/2023]
Abstract
Environmental compartments are repositories of probably thousands of emerging contaminants (ECs) released along with treated/untreated wastewater. Despite extensive studies on the detection of ECs in surface water, other environmental compartments such as sediments and groundwater are yet to be thoroughly investigated. To assess the heavy anthropogenic impact on the environment, 24 environmental samples comprising of surface water, sediment and groundwater collected from the Yamuna River basin of India were analyzed via target and suspect screening. The surface water and sediment samples were collected from upstream and downstream of densely populated cities and towns situated along the heavily contaminated river Yamuna. The groundwater samples were collected from shallow drinking water wells of the catchment. Liquid chromatography tandem mass-spectroscopy was used to quantify 10 widely consumed pharmaceuticals in the samples. The study also analyzed the potential health hazards posed by the quantified contaminants. In order to evaluate further, the surface water and groundwater samples were subjected to high resolution mass spectrometry (HRMS) screening against a library resulting in a list of 450 ECs in the surface water and 309 ECs in the groundwater. Agricultural chemicals and pharmaceuticals found abundantly in the samples and half of whom were reported first time. The risk quotient was calculated to assess the potential hazard of the target analytes.
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Affiliation(s)
- Pinakshi Biswas
- Department of Civil Engineering, Indian Institute of Technology Roorkee, Uttarakhand 247667, India.
| | - Bhanu Prakash Vellanki
- Department of Civil Engineering, Indian Institute of Technology Roorkee, Uttarakhand 247667, India.
| | - Absar Ahmad Kazmi
- Department of Civil Engineering, Indian Institute of Technology Roorkee, Uttarakhand 247667, India.
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Behnami A, Aghayani E, Benis KZ, Sattari M, Pourakbar M. Comparing the efficacy of various methods for sulfate radical generation for antibiotics degradation in synthetic wastewater: degradation mechanism, kinetics study, and toxicity assessment. RSC Adv 2022; 12:14945-14956. [PMID: 35702226 PMCID: PMC9115878 DOI: 10.1039/d2ra01618d] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 05/12/2022] [Indexed: 12/07/2022] Open
Abstract
In the present study the aim was to investigate and compare various activation processes for amoxicillin degradation. UV radiation, ultrasound, heat, and hydrogen peroxide were selected as the persulfate activation methods. The effects of various parameters such as pH, persulfate concentration, reaction time, AMX concentration, radical scavengers, and anions were thoroughly investigated. The results showed that AMX degradation was following the pseudo-first order kinetic model. The reaction rate of 0.114 min-1 was calculated for the UV/PS process, which was higher than that of the other investigated processes. The AMX degradation mechanism and pathway investigations revealed that sulfate and hydroxyl radicals were responsible for the degradation of AMX by two degradation pathways of hydroxylation and the opening of the β-lactam ring. Competition kinetic analysis showed that the second-order rate constant of AMX with sulfate radicals was 8.56 × 109 L mol-1 s-1 in the UV/PS process. Cost analysis was conducted for the four investigated processes and it was found that 1.9 $m-3 per order is required in the UV/PS process for the complete destruction of AMX. Finally, cytotoxic assessment of the treated effluent on human embryonic kidney cells showed a considerable reduction in AMX-induced cell cytotoxicity, proving that the investigated process is sufficiently capable of completely destroying AMX molecules to nontoxic compounds. Therefore, it can be concluded that UV radiation is much more effective than other methods for persulfate activation and can be considered as a reliable technique for antibiotic removal.
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Affiliation(s)
- Ali Behnami
- Department of Environmental Health Engineering, Maragheh University of Medical Sciences Maragheh Iran +98 04132726363
- Department of Environmental Health Engineering, Iran University of Medical Sciences Tehran Iran
| | - Ehsan Aghayani
- Research Center for Environmental Contaminants (RCEC), Abadan University of Medical Sciences Abadan Iran
| | - Khaled Zoroufchi Benis
- Department of Chemical and Biological Engineering, University of Saskatchewan Saskatoon Saskatchewan Canada
| | - Mohammad Sattari
- Department of Biophysics, Faculty of Biological Sciences, Malayer University Malayer Iran
| | - Mojtaba Pourakbar
- Department of Environmental Health Engineering, Maragheh University of Medical Sciences Maragheh Iran +98 04132726363
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22
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Using Sawdust Derived Biochar as a Novel 3D Particle Electrode for Micropollutants Degradation. WATER 2022. [DOI: 10.3390/w14030357] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This work examined the use of a 3D combined electrochemical process based on particle electrodes from sawdust-derived biochar pyrolized at T = 550–850 °C to remove persistent pollutants. The as-prepared biochar was characterized by scanning electron microscopy with an X-ray energy dispersive spectrometer (SEM/EDS), nitrogen adsorption (BET method) and X-ray diffraction (XRD) techniques. The use of sawdust biochar pyrolized at 650 °C led to a significant increase in efficiency against the sum of conventional 2D electrochemical systems and adsorption, and the synergy index estimated equal to 74.5% at optimum conditions. Sulfamethoxazole (SMX) removal was favored by increasing particle electrode loading. Despite that, the reaction was slightly favored in near-neutral conditions; the system retained most of its activity in the pH range 3–10. The proposed 3D system could degrade different micropollutants, namely SMX, Bisphenol A (BPA), Propylparaben (PP), and Piroxicam (PR). Of particular interest was that no significant reduction in degradation was observed in the case of complex or real water matrices. In addition, the system retained its efficiency regarding SMX removal after five sequential experiments in the 3D combined electrochemical process. However, further investigation is needed to estimate the contribution of the different mechanisms of micropollutant removal in the proposed system.
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Abstract
In this work, the photochemical treatment of a real municipal wastewater using a persulfate-driven photo-Fenton-like process was studied. The wastewater treatment efficiency was evaluated in terms of total carbon (TC), total organic carbon (TOC) and total nitrogen (TN) removal. Response surface methodology (RSM) in conjunction Box-Behnken design (BBD) and multilayer artificial neural network (ANN) have been utilized for the optimization of the treatment process. The effects of four independent factors such as reaction time, pH, K2S2O8 concentration and K2S2O8/Fe2+ molar ratio on the TC, TOC and TN removal have been investigated. The process significant factors have been determined implementing Analysis of Variance (ANOVA). Both RSM and ANN accurately found the optimum conditions for the maximum removal of TOC (100% and 98.7%, theoretically), which resulted in complete mineralization of TOC at the reaction time of 106.06 min, pH of 7.7, persulfate concentration of 30 mM and K2S2O8/Fe2+ molar ratio of 7.5 for RSM and at the reaction time of 104.93 min, pH of 7.7, persulfate concentration of 30 mM and K2S2O8/Fe2+ molar ratio of 9.57 for ANN. On the contrary, the attempts to find the optimal conditions for the maximum TC and TN removal using statistical, and neural network models were not successful.
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