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Liu F, Li H, Lei S, Yu Q, Ren H, Geng J. Enhanced degradation of pharmaceuticals in wastewater by coupled radical and non-radical pathways: Further unravelling kinetics and mechanism. JOURNAL OF HAZARDOUS MATERIALS 2023; 453:131362. [PMID: 37080036 DOI: 10.1016/j.jhazmat.2023.131362] [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: 01/04/2023] [Revised: 04/01/2023] [Accepted: 04/03/2023] [Indexed: 05/03/2023]
Abstract
Advanced oxidation processes based on radicals and/or non-radical catalysis are emerging as promising technologies for eliminating pharmaceuticals (PhACs) from wastewater. However, the respective contributions of different removal pathways (radicals or non-radical) for PhAC degradation still lacks quantitative investigation. Zero-valent iron and carbon nanotubes are frequently used to generate both radicals and non-radical species via the activation of persulfate (Fe0/SWCNT/PDS). Herein, the removal kinetics of 1 μM PhACs are depicted, and the corresponding synergistic mechanism of the Fe0/SWCNT/PDS process is discussed. Coupled removal pathways showed the higher degradation of PhACs than the individual pathways. Radicals quenching studies combined with electron spin resonance characterisation suggested that the radical-based removal pathway tends to attack electron-deficient organics, whereas its counterpart is more likely to work on electron-rich organics. From the perspectives of the contribution rate, the redox cycles of conjugated Fe species play a more important role in the generation of radicals than free Fe species, and the faster electron transfer in the conductive bridge offered by SWCNT is responsible for the effective corrosion of Fe0 and the decomposition of PDS. Six real wastewater samples were used to prove the generality of the above removal contribution, regardless of the wastewater samples, and the results suggested that identical attack patterns were obtained in all real wastewater samples, although coexistence matrix slightly suppressed PhAC removal. This work provides a deeper insight into the high-performance working mechanism on synergistic interactions and contaminant removal in a combined catalysis system.
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Affiliation(s)
- Fu Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hongzhou Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Shaoting Lei
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Qingmiao Yu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400044, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Jinju Geng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400044, PR China.
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2
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Huang M, Wang X, Zhu C, Zhu F, Liu P, Wang D, Fang G, Chen N, Gao S, Zhou D. Efficient chlorinated alkanes degradation in soil by combining alkali hydrolysis with thermally activated persulfate. JOURNAL OF HAZARDOUS MATERIALS 2022; 438:129571. [PMID: 35999732 DOI: 10.1016/j.jhazmat.2022.129571] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/07/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
Alkali activation is the most commonly used activation method for persulfate (PS) in in-situ remediation. However, the role of alkali in pollutant degradation is still elusive, limiting the optimization of relevant remediation strategies. In this study, we found that chlorinated alkanes (e.g., tetrachloroethane (TeCA)) could be efficiently degraded by thermal-alkali activation of PS. The main role of alkali was not activating PS but hydrolyzing the chlorinated alkanes, which was evidenced by the immediate conversion of TeCA into trichloroethylene (TCE) with NaOH and PS or with sole NaOH solution. Electron paramagnetic resonance analysis also showed that with a high NaOH/PS molar ratio (4:1) the intensity of oxidative radicals decreased, implying that high levels of alkali did not favor the formation of free radicals. Interestingly, better degradation of TeCA and its product TCE was observed by the combination of alkaline hydrolysis and thermal activation of PS (where alkali was added 6 h before PS rather than simultaneously) in comparison to thermal-alkali activation of PS. This study provides new insights into the remediation of chlorinated alkane-contaminated soils by in-situ chemical oxidation.
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Affiliation(s)
- Mingquan Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Xiaolei Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Changyin Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
| | - Fengxiao Zhu
- School of Environment, Nanjing Normal University, Nanjing 210023, PR China
| | - Peng Liu
- Beijing Construction Engineering Group Environmental Remediation Co. Ltd., Beijing 100015, PR China
| | - Dixiang Wang
- Beijing Construction Engineering Group Environmental Remediation Co. Ltd., Beijing 100015, PR China
| | - Guodong Fang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Ning Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Shixiang Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Dongmei Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
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Laboratory Experiments to Evaluate the Effectiveness of Persulfate to Oxidize BTEX in Saline Environment and at Elevated Temperature Using Stable Isotopes. HYDROLOGY 2021. [DOI: 10.3390/hydrology8030139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this study, batch experiments were carried out to investigate the effectiveness of persulfate (PS) as an oxidant agent to remediate benzene, toluene, ethylbenzene, and xylenes (BTEX) in saline environments and at high water temperatures (30 °C). This hydrological setting is quite common in contaminated groundwater aquifers in Middle Eastern countries. In general, increasing the system temperature from 10 to 30 °C greatly enhanced the effectiveness of PS, and resulted in a faster oxidation rate for the target contaminants. When PS was added to the reactor at 30 °C, the targeted contaminants were almost completely oxidized over a 98-day reaction period. During the chemical oxidation of the BTEX, carbon and hydrogen isotope fractionations were monitored and utilized as potential proof of contaminant degradation. The calculated carbon-enrichment values were −1.9‰ for benzene, −1.5‰ for ethylbenzene and toluene, −0.4‰ for ρ,m-xylene, and −1.4‰ for o-xylene, while the hydrogen enrichment values were −9.5‰, −6.8‰, −2.1‰, −6.9‰, and −9.1‰, respectively. In comparison with other processes, the hydrogen and carbon isotope fractionations during the chemical oxidation by PS were smaller than the isotope fractionations resulting from sulfate reduction and denitrification. This observation demonstrates the differences in the transformation pathways and isotope fractionations when compounds undergo chemical oxidation or biodegradation. The distinct trend observed on the dual isotope plot (Δδ13C vs. Δδ2H) suggests that compound-specific isotope analysis can be utilized to monitor the chemical oxidation of BTEX by PS, and to distinguish treatment zones where PS and biodegradation technologies are applied simultaneously.
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Guo Z, Bai G, Huang B, Cai N, Guo P, Chen L. Preparation and application of a novel biochar-supported red mud catalyst:Active sites and catalytic mechanism. JOURNAL OF HAZARDOUS MATERIALS 2021; 408:124802. [PMID: 33370698 DOI: 10.1016/j.jhazmat.2020.124802] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/02/2020] [Accepted: 12/06/2020] [Indexed: 06/12/2023]
Abstract
A novel catalyst RM-BC(HP) was synthesized by hydrothermal treatment and pyrolysis (800 ℃) using red mud and coconut shells. Influence of different preparation conditions on catalyst performance was explored. SEM showed that RM-BC(HP) was porous and RM was successfully loaded on the outside surface and inside the pores of BC. XRD revealed that Fe2O3 in RM was reduced to Fe0 and Fe3O4 in the pyrolysis process, in which pyrolysis temperature and addition ratio of coconut shells were critical. TGA-MS, FT-IR and XPS were also applied to character the catalyst. 100% of AO7 was removed within 30 min with conditions of 2 mM PS, 50 mg/L AO7 and 0.5 g/L RM-BC(HP), and the Fe leaching was negligible. High removal rate was obtained in tap, river, and lake water. RM-BC(HP)/PS system also exhibited excellent degradation performance for other dyes (MB, MG and RhB) and antibiotics (TC, OTC and CTC). The mechanism studies demonstrated that PS was mainly activated by Fe0 and Fe2+ in RM-BC(HP) to produce different radicals, then 1O2 was generated by the reactions among these radicals to degrade AO7. Finally, nine intermediate products of AO7 were identified by FT-ICR-MS and a probable degradation pathway was proposed.
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Affiliation(s)
- Ziwei Guo
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; Guangdong Provincial Engineering Research Center for Online Monitoring of Water Pollution, Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Guangdong Institute of Analysis (China National Analytical Center Guangzhou), Guangdong Academy of Sciences, Guangzhou 510000, China
| | - Ge Bai
- Guangdong Provincial Engineering Research Center for Online Monitoring of Water Pollution, Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Guangdong Institute of Analysis (China National Analytical Center Guangzhou), Guangdong Academy of Sciences, Guangzhou 510000, China; College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730000, China
| | - Bing Huang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Nan Cai
- Guangdong Provincial Engineering Research Center for Online Monitoring of Water Pollution, Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Guangdong Institute of Analysis (China National Analytical Center Guangzhou), Guangdong Academy of Sciences, Guangzhou 510000, China
| | - Pengran Guo
- Guangdong Provincial Engineering Research Center for Online Monitoring of Water Pollution, Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Guangdong Institute of Analysis (China National Analytical Center Guangzhou), Guangdong Academy of Sciences, Guangzhou 510000, China.
| | - Liang Chen
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
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Head NA, Gerhard JI, Inglis AM, Nunez Garcia A, Chowdhury AIA, Reynolds DA, de Boer CV, Sidebottom A, Austrins LM, Eimers J, O'Carroll DM. Field test of electrokinetically-delivered thermally activated persulfate for remediation of chlorinated solvents in clay. WATER RESEARCH 2020; 183:116061. [PMID: 32623242 DOI: 10.1016/j.watres.2020.116061] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 06/12/2020] [Accepted: 06/13/2020] [Indexed: 06/11/2023]
Abstract
In situ chemical oxidation (ISCO) has demonstrated success in remediating soil and groundwater contaminated with chlorinated volatile organic compounds (CVOCs). However, its performance is often hindered in low-permeability or heterogeneous media due to an inability to effectively deliver the oxidants. This field-scale study investigated the novel approach of applying electrokinetics (EK) to enhance the delivery of persulfate in a low-permeability media and the ability of electrical resistance heating (ERH) to thermally activate the delivered persulfate. Results showed that 40% of the mass of total sulfur delivered was due to EK mechanisms, demonstrating that EK has the potential to enhance oxidant delivery. ERH may have activated some of the persulfate, but catalytic reactions with reduced forms of iron likely resulted in appreciable persulfate decomposition prior to ERH. Significant decreases (>80%) in the aqueous concentration of CVOCs was observed before and after ERH initiation, attributed to in situ transformation and physical processes (e.g., dilution). In situ transformation of CVOCs was assessed by compound-specific isotope analysis (CSIA) of 1,2-dichloroethane (1,2-DCA) samples collected after ERH application. Enrichment of 13C was only measured in the well with appreciable persulfate breakthrough, confirming dechlorination of 1,2-DCA. Results from this field study demonstrate that EK and ERH can be used for persulfate delivery and activation for remediation of CVOCs in low-permeability media.
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Affiliation(s)
- Nicholas A Head
- Department of Civil and Environmental Engineering, University of Western Ontario, 1151 Richmond Rd., London, Ontario, N6A 5B8, Canada
| | - Jason I Gerhard
- Department of Civil and Environmental Engineering, University of Western Ontario, 1151 Richmond Rd., London, Ontario, N6A 5B8, Canada
| | - Ainsley M Inglis
- Department of Civil and Environmental Engineering, University of Western Ontario, 1151 Richmond Rd., London, Ontario, N6A 5B8, Canada
| | - Ariel Nunez Garcia
- Department of Civil and Environmental Engineering, University of Western Ontario, 1151 Richmond Rd., London, Ontario, N6A 5B8, Canada
| | - Ahmed I A Chowdhury
- Institute of Water and Flood Management, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh
| | - David A Reynolds
- Geosyntec Consultants, 130 Stone Road W, Guelph, N1G 3Z2, ON, Canada
| | - Cjestmir V de Boer
- Netherlands Organization for Applied Research, TNO, Princetonlaan 6, 3584 CB, Utrecht, the Netherlands
| | | | - Leanne M Austrins
- Dow Chemical, Environmental Remediation and Compliance, Midland, MI, 48674, USA
| | - Jake Eimers
- Jacobs, 72 Victoria St S, Kitchener, N2G 4Y9, ON, Canada
| | - Denis M O'Carroll
- School of Civil and Environmental Engineering, Water Research Centre, University of New South Wales, Sydney, NSW, 2052, Australia.
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New insight into the mechanism of peroxymonosulfate activation by nanoscaled lead-based spinel for organic matters degradation: A singlet oxygen-dominated oxidation process. J Colloid Interface Sci 2020; 572:318-327. [PMID: 32272310 DOI: 10.1016/j.jcis.2020.03.116] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/26/2020] [Accepted: 03/29/2020] [Indexed: 02/03/2023]
Abstract
Crystalline iron-based nanoparticles with spinel structure have received great attention for catalyzing peroxymonosulfate (PMS). This study introduces lead ferrite (PbFe2O4) as a novel, simple, and efficient catalyst to activate PMS for the degradation of organic contaminants in aqueous solution. The results indicated that, under pH 9.0, nearly 100% of 10 μM thionine was removed in 20 min. Operation factors, including pH, oxidant concentrations, catalyst dosage, and coexisting ions, were investigated and found to be influential for the thionine removal. PbFe2O4 showed higher catalytic activity and lower ions leaching than well-crystallized lead oxide (PbO) and ferric oxide (Fe2O3). The results from the characterization of the PbFe2O4 with X-ray diffraction (XRD) before and after reaction suggested that the structure and properties of the catalyst kept stable, and the recovered catalyst exhibited good catalytic performance during the recycling batch experiments. Free radical quenching experiments and electron paramagnetic resonance (EPR) spectra revealed that singlet-oxygen (1O2) is the dominant active oxygen species rather than sulfate radical for thionine degradation in PbFe2O4/PMS system. Meanwhile, the possible pathways of 1O2 generation were proposed: the redox reaction between Pb(Ⅳ)/Pb(II) and PMS may play an key role in PMS activation. This study provides an interesting insight in PMS activation by the high-efficient non-radical process, and the PbFe2O4 could be as efficient and recyclable heterogeneous catalyst for organic degradation.
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7
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Wang Y, Tian D, Chu W, Li M, Lu X. Nanoscaled magnetic CuFe2O4 as an activator of peroxymonosulfate for the degradation of antibiotics norfloxacin. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2018.11.051] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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8
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Wang W, Wu Y. Sequential coupling of bio-augmented permeable reactive barriers for remediation of 1,1,1-trichloroethane contaminated groundwater. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:12042-12054. [PMID: 30827025 DOI: 10.1007/s11356-019-04676-3] [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: 04/23/2018] [Accepted: 02/22/2019] [Indexed: 06/09/2023]
Abstract
Sequential coupling of high-density luffa sponge (HDLS) immobilized microorganism and permeable reactive barriers (IM Bio-PRBs) was superior to intimate coupling of free microorganism and permeable reactive barriers (FM Bio-PRBs) for remediation of 1,1,1-trichloroethane contaminated groundwater. IM Bio-PRBs had much better performance to removal 1,1,1-trichloroethane (1,1,1-TCA) and prevent the transport of 1,1,1-TCA and inorganic ions (NO3-, PO43-, and SO42-). The majority of them were prevented and accumulated in upgradient of IM Bio-PRBs. 1,1,1-TCA and inorganic ions in there contributed to the much faster growth of microorganism in upgradient aquifer. Therefore, the removal of 1,1,1-TCA and consumption of inorganic ions in upgradient of Bio-PRBs played a constructive role in reducing the processing load of following zero-valent iron (ZVI) PRBs and the negative effect of free microorganism cells (biological clogging) and inorganic ions (chemical clogging) on Bio-PRB permeability. In addition, IM Bio-PRBs were more conducive to accelerate the removal of 1,1,1-TCA in long-term remediation and 1,1,1-TCA residual concentration significantly lower than the safety standard of 0.2 mg L-1. The change of terminal by-products of 1,1,1-TCA contaminated groundwater in Bio-PRBs showed that 1,1,1-TCA could be effectively de-chlorinated and mineralized in Bio-PRBs. The reductant H2S (prolong the service life of ZVI-PRBs) was much more produced and utilized in IM Bio-PRBs. Taken together, sequentially coupled IM Bio-PRBs had a better overall performance, and its service life could be prolonged. It was a different design and idea to update conventional PRB remediation technology and theory.
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Affiliation(s)
- Wenbing Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
| | - Yanqing Wu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China.
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Wang W, Wu Y. Effects of biological clogging on 1,1,1-TCA and its intermediates distribution and fate in heterogeneous saturated bio-augmented permeable reactive barriers. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:28628-28641. [PMID: 30094670 DOI: 10.1007/s11356-018-2908-z] [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: 04/18/2018] [Accepted: 08/03/2018] [Indexed: 06/08/2023]
Abstract
Biological clogging in porous media was an important concern in the design of bio-augmented permeable reactive barriers (Bio-PRBs) that were used to remediate groundwater with dense non-aqueous phase liquids (DNAPLs). Here, we used laboratory sandbox experiments to develop and calibrate reactive transport models (C1 and C2) simulating 1,1,1-trichloroethane (1,1,1-TCA) change in heterogeneous saturated porous media. The routine (1,1,1-TCA chain kinetic reactions) and subroutine (the relationship between hydraulic conductivity (K) and time (t)) were included in the model computer code. The simulation results suggested that the model C1 had the applicability for simulating contaminant transport and fate in bio-augmented flow field. By using the model C1 which was suitable for constant K condition, the performance of different types of Bio-PRBs was evaluated, and the regularity of contaminants chain kinetic reactions in different heterogeneous saturated porous media was obtained. The results demonstrated that Bio-PRBs in immobilized microorganism (IM) protocol were more superior to Bio-PRBs in free microorganism (FM) protocol. In addition, by using the model C2 (updated model C1) which was suitable for decreasing K condition, the different and optimized regularity of contaminants transport and transformation was obtained. The results showed that microbial growth which further decreased K was beneficial to preventing the transport of contaminants and accelerating the transformation of contaminants. However, the negative effects of biological clogging on hydraulic conductivity and relative hydraulic conductivity ratio in FM Bio-PRBs were significantly stronger than that in IM Bio-PRBs. Deploying IM Bio-PRBs for groundwater remediation would be much more efficient and meet the design criteria. The research work had guiding significance to engineering and provided consultation for designing and optimizing Bio-PRBs system. To make the design and optimization of Bio-PRBs system convenient, it was very essential to choose the suitable mathematical model (C1 or C2).
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Affiliation(s)
- Wenbing Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
| | - Yanqing Wu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China.
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Ma J, Li H, Chi L, Chen H, Chen C. Changes in activation energy and kinetics of heat-activated persulfate oxidation of phenol in response to changes in pH and temperature. CHEMOSPHERE 2017; 189:86-93. [PMID: 28934658 DOI: 10.1016/j.chemosphere.2017.09.051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 09/07/2017] [Accepted: 09/12/2017] [Indexed: 06/07/2023]
Abstract
Persulfate (peroxydisulfate, S2O82-) is the newest oxidant used for the in situ chemical oxidation (ISCO) remediation of soil and groundwater. The present study investigated impacts of solution pH, temperature, and persulfate concentration on the reaction rate constant (k1), activation energy (Ea), and reaction order of the heat-activated persulfate process. Phenol was chosen as the model organic contaminant. As temperature increased from 30 °C to 70 °C, k1 exhibited a significant increase from 0.003 h-1∼0.962 h-1 (pH 1.3-13.9) to 1.184 h-1∼9.91 h-1 (pH 1.3-13.9), which corroborated with the activation of persulfate using heat. As pH increased from 1.3 to 13.9, k1 exhibited a 4.3-fold increase at 70 °C and a 320-fold increase at 30 °C, thereby suggesting that: 1) the phenol oxidation rate increased under alkaline conditions, and 2) the enhancement of reaction rate due to alkaline activation was more pronounced at a lower temperature. Increasing pH significantly reduced Ea from 139.7 ± 1.3 kJ/mol at pH 1.3 to 52.0 ± 3.3 kJ/mol at pH 13.9. In contrast to changing pH, increasing persulfate concentration from 20 to 320 mM significantly increased k1 but did not affect Ea. Changes in Ea suggest that persulfate oxidation of phenol experienced different reaction pathways or elementary reaction sequences as the pH changed from 1.3 to 13.9. In addition, the k1 and Ea data also suggest that a minimal pH threshold of ∼11 was required for the effective alkaline activation of persulfate.
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Affiliation(s)
- Jie Ma
- State Key Laboratory of Heavy Oil Processing, State Key Laboratory of Petroleum Pollution Control, Beijing Key Lab of Oil & Gas Pollution Control, China University of Petroleum-Beijing, Beijing, 102249, China.
| | - Haiyan Li
- State Key Laboratory of Heavy Oil Processing, State Key Laboratory of Petroleum Pollution Control, Beijing Key Lab of Oil & Gas Pollution Control, China University of Petroleum-Beijing, Beijing, 102249, China
| | - Liping Chi
- State Key Laboratory of Heavy Oil Processing, State Key Laboratory of Petroleum Pollution Control, Beijing Key Lab of Oil & Gas Pollution Control, China University of Petroleum-Beijing, Beijing, 102249, China
| | - Hongkun Chen
- State Key Laboratory of Petroleum Pollution Control, CNPC Research Institute of Safety & Environment Technology, Beijing, 102206, China
| | - Changzhao Chen
- State Key Laboratory of Petroleum Pollution Control, CNPC Research Institute of Safety & Environment Technology, Beijing, 102206, China
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11
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Torrentó C, Palau J, Rodríguez-Fernández D, Heckel B, Meyer A, Domènech C, Rosell M, Soler A, Elsner M, Hunkeler D. Carbon and Chlorine Isotope Fractionation Patterns Associated with Different Engineered Chloroform Transformation Reactions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:6174-6184. [PMID: 28482655 DOI: 10.1021/acs.est.7b00679] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
To use compound-specific isotope analysis for confidently assessing organic contaminant attenuation in the environment, isotope fractionation patterns associated with different transformation mechanisms must first be explored in laboratory experiments. To deliver this information for the common groundwater contaminant chloroform (CF), this study investigated for the first time both carbon and chlorine isotope fractionation for three different engineered reactions: oxidative C-H bond cleavage using heat-activated persulfate, transformation under alkaline conditions (pH ∼ 12) and reductive C-Cl bond cleavage by cast zerovalent iron, Fe(0). Carbon and chlorine isotope fractionation values were -8 ± 1‰ and -0.44 ± 0.06‰ for oxidation, -57 ± 5‰ and -4.4 ± 0.4‰ for alkaline hydrolysis (pH 11.84 ± 0.03), and -33 ± 11‰ and -3 ± 1‰ for dechlorination, respectively. Carbon and chlorine apparent kinetic isotope effects (AKIEs) were in general agreement with expected mechanisms (C-H bond cleavage in oxidation by persulfate, C-Cl bond cleavage in Fe(0)-mediated reductive dechlorination and E1CB elimination mechanism during alkaline hydrolysis) where a secondary AKIECl (1.00045 ± 0.00004) was observed for oxidation. The different dual carbon-chlorine (Δδ13C vs Δδ37Cl) isotope patterns for oxidation by thermally activated persulfate and alkaline hydrolysis (17 ± 2 and 13.0 ± 0.8, respectively) vs reductive dechlorination by Fe(0) (8 ± 2) establish a base to identify and quantify these CF degradation mechanisms in the field.
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Affiliation(s)
- Clara Torrentó
- Centre for Hydrogeology and Geothermics, Université de Neuchâtel , 2000 Neuchâtel, Switzerland
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Jordi Palau
- Centre for Hydrogeology and Geothermics, Université de Neuchâtel , 2000 Neuchâtel, Switzerland
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Diana Rodríguez-Fernández
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Benjamin Heckel
- Institute of Groundwater Ecology, Helmholtz Zentrum München , 85764 Neuherberg, Germany
| | - Armin Meyer
- Institute of Groundwater Ecology, Helmholtz Zentrum München , 85764 Neuherberg, Germany
| | - Cristina Domènech
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Mònica Rosell
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Albert Soler
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München , 85764 Neuherberg, Germany
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich , Marchioninistrasse 17, D-81377 Munich, Germany
| | - Daniel Hunkeler
- Centre for Hydrogeology and Geothermics, Université de Neuchâtel , 2000 Neuchâtel, Switzerland
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Gu X, Lu S, Fu X, Qiu Z, Sui Q, Guo X. Carbon dioxide radical anion-based UV/S2O82−/HCOOH reductive process for carbon tetrachloride degradation in aqueous solution. Sep Purif Technol 2017. [DOI: 10.1016/j.seppur.2016.08.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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13
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Zhong H, Tian Y, Yang Q, Brusseau ML, Yang L, Zeng G. Degradation of landfill leachate compounds by persulfate for groundwater remediation. CHEMICAL ENGINEERING JOURNAL (LAUSANNE, SWITZERLAND : 1996) 2017; 307:399-407. [PMID: 28584519 PMCID: PMC5456458 DOI: 10.1016/j.cej.2016.08.069] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In this study, batch and column experiments were conducted to evaluate the feasibility of using persulfate oxidation to treat groundwater contaminated by landfill leachate (CGW). In batch experiments, persulfate was compared with H2O2, and permanganate for oxidation of organic compounds in CGW. It was also compared with the potential of biodegradation for contaminant removal from CGW. Persulfate was observed to be superior to H2O2 and permanganate for degradation of total organic carbon (TOC) in the CGW. Conversely, biodegradation caused only partial removal of TOC in CGW. In contrast, persulfate caused complete degradation of the TOC in the CGW or aged CGW, showing no selectivity limitation to the contaminants. Magnetite (Fe3O4) enhanced degradation of leachate compounds in both CGW and aged CGW with limited increase in persulfate consumption and sulfate production. Under dynamic flow condition in 1-D column experiments, both biodegradation and persulfate oxidation of TOC were enhanced by Fe3O4. The enhancement, however, was significantly greater for persulfate oxidation. In both batch and column experiments, Fe3O4 by itself caused minimal consumption of persulfate and production of sulfate, indicating that magnetite is a good persulfate activator for treating CGW in heterogeneous systems The results of the study show that the persulfate-based in-situ chemical oxidation (ISCO) method has great potential to treat the groundwater contaminated by landfill leachate.
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Affiliation(s)
- Hua Zhong
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
- School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan 430070, China
- Department of Soil, Water and Environmental Science, University of Arizona, Tucson, Arizona 85721
- Corresponding author: Hua Zhong; Tel: +15206264191; ;
| | - Yaling Tian
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
- Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China
| | - Qi Yang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
- Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China
| | - Mark L Brusseau
- Department of Soil, Water and Environmental Science, University of Arizona, Tucson, Arizona 85721
| | - Lei Yang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
- Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China
| | - Guangming Zeng
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
- Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China
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Combination of zero-valent iron and anaerobic microorganisms immobilized in luffa sponge for degrading 1,1,1-trichloroethane and the relevant microbial community analysis. Appl Microbiol Biotechnol 2016; 101:783-796. [DOI: 10.1007/s00253-016-7933-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 09/07/2016] [Accepted: 10/12/2016] [Indexed: 11/25/2022]
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15
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Qi C, Liu X, Ma J, Lin C, Li X, Zhang H. Activation of peroxymonosulfate by base: Implications for the degradation of organic pollutants. CHEMOSPHERE 2016; 151:280-8. [PMID: 26946115 DOI: 10.1016/j.chemosphere.2016.02.089] [Citation(s) in RCA: 426] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/15/2016] [Accepted: 02/21/2016] [Indexed: 05/28/2023]
Abstract
Increasing attention has been paid to environmentally friendly activation methods of peroxymonosulfate (PMS) in advanced oxidation processes (AOPs) for organic pollutant elimination. This work demonstrates that Base can be applied as a novel activator for PMS. The Base/PMS system, at ambient temperature, was able to degrade a variety of organic pollutants, including acid orange 7 (AO7), phenol and bisphenol A. In subsequent experiments with AO7, the decolorization rates for AO7 followed pseudo-first-order kinetics, with rate constant values ranging from 0.0006 to 0.1749 min(-1) depending on the operating parameters (initial PMS, Base, AO7 concentrations and reaction temperature). Furthermore, the mechanism for PMS activation by the Base was elucidated by radical scavenger (tert-butyl alcohol, methanol, sodium azide and p-benzoquinone) and electron spin resonance trapping studies. The results revealed that superoxide anion radical and singlet oxygen other than sulfate radical were the primary reactive oxygen species in the Base/PMS system. The findings of this study present a new pathway for PMS activation and provide useful information for the treatment of wastewater.
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Affiliation(s)
- Chengdu Qi
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Xitao Liu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Jun Ma
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Chunye Lin
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Xiaowan Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Huijuan Zhang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
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16
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Liu Y, Zhou A, Gan Y, Li X. Variability in carbon isotope fractionation of trichloroethene during degradation by persulfate activated with zero-valent iron: Effects of inorganic anions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 548-549:1-5. [PMID: 26784392 DOI: 10.1016/j.scitotenv.2016.01.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 01/03/2016] [Accepted: 01/03/2016] [Indexed: 06/05/2023]
Abstract
Stable carbon isotope analysis has the potential to be used for assessing the performance of in situ remediation of organic contaminants. Successful application of this isotope technique requires understanding the magnitude and variability in carbon isotope fractionation associated with the reactions under consideration. This study investigated the influence of inorganic anions (sulfate, bicarbonate, and chloride) on carbon isotope fractionation of trichloroethene (TCE) during its degradation by persulfate activated with zero-valent iron. The results demonstrated that the significant carbon isotope fractionation (enrichment factors ε ranging from -3.4±0.3 to -4.3±0.3‰) was independent on the zero-iron dosage, sulfate concentration, and bicarbonate concentration. However, the ε values (ranging from -7.0±0.4 to -13.6±1.2‰) were dependent on the chloride concentration, indicating that chloride could significantly affect carbon isotope fractionation during TCE degradation by persulfate activated with zero-valent iron. The dependence of ε values on chloride concentration, indicated that TCE degradation mechanisms may be different from the degradation mechanism caused by sulfate radical (SO4(-)). Ignoring the effect of chloride on ε value may cause numerous uncertainties in quantitative assessment of the performance of the in situ chemical oxidation (ISCO).
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Affiliation(s)
- Yunde Liu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Aiguo Zhou
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.
| | - Yiqun Gan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Xiaoqian Li
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
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Palau J, Shouakar-Stash O, Hunkeler D. Carbon and chlorine isotope analysis to identify abiotic degradation pathways of 1,1,1-trichloroethane. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:14400-14408. [PMID: 25379605 DOI: 10.1021/es504252z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This study investigates dual C-Cl isotope fractionation during 1,1,1-TCA transformation by heat-activated persulfate (PS), hydrolysis/dehydrohalogenation (HY/DH) and Fe(0). Compound-specific chlorine isotope analysis of 1,1,1-TCA was performed for the first time, and transformation-associated isotope fractionation ε bulk C and ε bulk Cl values were -4.0 ± 0.2‰ and no chlorine isotope fractionation with PS, -1.6 ± 0.2‰ and -4.7 ± 0.1‰ for HY/DH, -7.8 ± 0.4‰ and -5.2 ± 0.2‰ with Fe(0). Distinctly different dual isotope slopes (Δδ13C/Δδ37Cl): ∞ with PS, 0.33 ± 0.04 for HY/DH and 1.5 ± 0.1 with Fe(0) highlight the potential of this approach to identify abiotic degradation pathways of 1,1,1-TCA in the field. The trend observed with PS agreed with a C-H bond oxidation mechanism in the first reaction step. For HY/DH and Fe(0) pathways, different slopes were obtained although both pathways involve cleavage of a C-Cl bond in their initial reaction step. In contrast to the expected larger primary carbon isotope effects relative to chlorine for C-Cl bond cleavage, ε bulk C < ε bulk Cl was observed for HY/DH and in a similar range for reduction by Fe(0), suggesting the contribution of secondary chlorine isotope effects. Therefore, different magnitude of secondary chlorine isotope effects could at least be partly responsible for the distinct slopes between HY/DH and Fe(0) pathways. Following this dual isotope approach, abiotic transformation processes can unambiguously be identified and quantified.
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Affiliation(s)
- Jordi Palau
- Centre for Hydrogeology and Geothermics, University of Neuchâtel , Neuchâtel CH-2000, Switzerland
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