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Yuan L, Wang K, Zhao Q, Yang L, Wang G, Jiang M, Li L. An overview of in situ remediation for groundwater co-contaminated with heavy metals and petroleum hydrocarbons. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 349:119342. [PMID: 37890298 DOI: 10.1016/j.jenvman.2023.119342] [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: 06/20/2023] [Revised: 10/11/2023] [Accepted: 10/14/2023] [Indexed: 10/29/2023]
Abstract
Groundwater is an important component of water resources. Mixed pollutants comprising heavy metals (HMs) and petroleum hydrocarbons (PHs) from industrial activities can contaminate groundwater through such processes as rainfall infiltration, runoff and discharge, which pose direct threats to human health through the food chain or drinking water. In situ remediation of contaminated groundwater is an important way to improve the quality of a water environment, develop water resources and ensure the safety of drinking water. Bioremediation and permeable reactive barriers (PRBs) were discussed in this paper as they were effective and affordable for in situ remediation of complex contaminated groundwater. In addition, media types, technology combinations and factors for the PRBs were highlighted. Finally, insights and outlooks were presented for in situ remediation technologies for complex groundwater contaminated with HMs and PHs. The selection of an in situ remediation technology should be site specific. The remediation of complex contaminated groundwater can be approached from various perspectives, including the development of economical materials, the production of slow-release and encapsulated materials, and a combination of multiple technologies. This review is expected to provide technical guidance and assistance for in situ remediation of complex contaminated groundwater.
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Affiliation(s)
- Luzi Yuan
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Kun Wang
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Qingliang Zhao
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
| | - Lin Yang
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Guangzhi Wang
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Miao Jiang
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Lili Li
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
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Mao Y, Xie Z, Shen D, Qi S. Influence of static pressure on toluene oxidation efficiency in groundwater by micro-nano bubble ozonation. CHEMOSPHERE 2024; 347:140708. [PMID: 37967678 DOI: 10.1016/j.chemosphere.2023.140708] [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: 10/12/2023] [Revised: 11/07/2023] [Accepted: 11/12/2023] [Indexed: 11/17/2023]
Abstract
Micro-nano bubble ozonation has been widely applied in the purification of drinking water due to its superior characteristics such as high mass transfer rate and long resistance time. However, its application in groundwater remediation is limited, partially due to the unclear effect of static water pressure on the oxidation efficiency. This study constructed a batch reactor to investigate the influence of static pressure on toluene oxidation by ozone micro-nano bubble water. To achieve constant pressure, weight was added above the mobile reactor roof, and the initial concentrations of toluene and dissolved ozone were 1.00 mg L-1 and 0.68 mg L-1 respectively. Experimental results demonstrated that as the static water pressure increased from 0.0 to 2.5 m, the average microbubble diameter decreased significantly from 62.3 to 36.0 μm. Simultaneously, the oxidation percentage of toluene increased from 40.3% to 58.7%, and the reaction rate between toluene and hydroxyl radical (OH·) increased from 9.3 × 109 to 1.39 × 1010 M-1 s-1, indicating that the shrinkage of micro-nano bubbles generated an abundance of OH· that quickly oxidized toluene adsorbed at the bubble interface. A greater enhancement of oxidation efficiency for nitrobenzene, as compared to p-xylene, was observed after the addition of 2.5 m water pressure, which verified the larger contribution of OH· under static pressure. Although the improvement of oxidation efficiency was reduced under acid and alkaline environments, as well as in practical groundwater matrices, the overall results still demonstrated the promising application of micro-nano bubble ozonation in groundwater remediation.
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Affiliation(s)
- Yuqin Mao
- College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou, 310015, China
| | - Zeming Xie
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Zhejiang Engineering Research Center of Non-ferrous Metal Waste Recycling, Zhejiang Gongshang University, Hangzhou, 310012, China
| | - Dongsheng Shen
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Zhejiang Engineering Research Center of Non-ferrous Metal Waste Recycling, Zhejiang Gongshang University, Hangzhou, 310012, China
| | - Shengqi Qi
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Zhejiang Engineering Research Center of Non-ferrous Metal Waste Recycling, Zhejiang Gongshang University, Hangzhou, 310012, China.
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Wang J, Zhang Y, Liu T, Shi Y, Ding Y, Zhang Y, Xu W, Zhang X, Wang Y, Li D. A biodegradable chitosan-based polymer for sustained nutrient release to stimulate groundwater hydrocarbon-degrading microflora. CHEMOSPHERE 2023; 344:140346. [PMID: 37832890 DOI: 10.1016/j.chemosphere.2023.140346] [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: 05/01/2023] [Revised: 09/21/2023] [Accepted: 09/30/2023] [Indexed: 10/15/2023]
Abstract
Petroleum hydrocarbon-contaminated groundwater often has a low indigenous microorganism population and lacks the necessary nutrient substrates for biodegradation reaction, resulting in a weak natural remediation ability within the groundwater ecosystem. In this paper, we utilized the principle of petroleum hydrocarbon degradation by microorganisms to identify effective nutrients (NaH2PO4, K2HPO4, NH4NO3, CaCl2, MgSO4·7H2O, FeSO4·7H2O, and VB12) and optimize nutrient substrate allocation through a combination of actual surveys of petroleum hydrocarbon-contaminated sites and microcosm experiments. Building on this, combining biostimulation and controlled-release technology, we developed a biodegradable chitosan-based encapsulated targeted biostimulant (i.e., YZ-1) characterized by easy uptake, good stability, controllable slow-release migration, and longevity to stimulate indigenous microflora in groundwater to efficiently degrade petroleum hydrocarbon. Results showed that YZ-1 extended the active duration of nutrient components by 5-6 times, with a sustainable release time exceeding 2 months. Under YZ-1 stimulation, microorganisms grew rapidly, increasing the degradation rate of petroleum hydrocarbon (10 mg L-1) by indigenous microorganisms from 43.03% to 79.80% within 7 d. YZ-1 can easily adapt to varying concentrations of petroleum hydrocarbon-contaminated groundwater. Specifically, in the range of 2-20 mg L-1 of petroleum hydrocarbon, the indigenous microflora was able to degrade 71.73-80.54% of the petroleum hydrocarbon within a mere 7 d. YZ-1 injection facilitated the delivery of nutrient components into the underground environment, improved the conversion ability of inorganic electron donors/receptors in the indigenous microbial community system, and strengthened the co-metabolism mechanism among microorganisms, achieving the goal of efficient petroleum hydrocarbon degradation.
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Affiliation(s)
- Jili Wang
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021,China
| | - Yuling Zhang
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021,China.
| | - Ting Liu
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021,China
| | - Yujia Shi
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021,China; Changchun Gold Research Institute Co., Ltd, Changchun 130021, China
| | - Yang Ding
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021,China
| | - Yi Zhang
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021,China
| | - Weiqing Xu
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021,China
| | - Xinying Zhang
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021,China
| | - Yiliang Wang
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021,China
| | - Dong Li
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021,China
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Liu SH, Lin HH. Enhancement of isopropanol removal with concomitant power generation by microbial fuel cells: Optimization of deoxidizing composite anodes using response surface methodology. CHEMOSPHERE 2022; 286:131732. [PMID: 34364227 DOI: 10.1016/j.chemosphere.2021.131732] [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: 06/08/2021] [Revised: 07/12/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
This study used a response surface method to develop a deoxidizing anode, which was introduced into microbial fuel cells (MFCs) to treat isopropanol (IPA) wastewater and waste gas. By embedding a deoxidizing agent (DA) into the anode of MFCs, a hypoxic environment can be created to enable anaerobic electrogens to be effectively attached to the anode surface and grow. Consequently, MFC power generation performance can be enhanced. The optimal coke and conductive carbon black ratio of an anode and percentage of DA added were 3.61 g/g and 3.15 %, respectively. The research design concurrently achieved the maximum deoxygenation efficiency (0.86 mg O2/bead), minimum disintegration ratio (3.51 %), and minimum resistance (30.2 Ω). The regression model had high prediction power (R2 > 0.93) for anode performance. As determined through multi-objective optimization, the results highly satisfied the target expectation (desirability = 0.82). The optimized deoxidizing anode was filled into an air-cathode MFC, which had a higher IPA removal efficiency (1.15-fold) and voltage output (1.24-fold) than an MFC filled with coke. The results for the trickling-bed MFC filled with a deoxidizing anode revealed that when the inlet concentration was 0.74 g/m3, the voltage output and power density were highest at 416.3 mV and 486.6 mW/m3, respectively. The deoxidizing anode developed has the potential to increase the MFC voltage output and the pollutant removal.
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Affiliation(s)
- Shu-Hui Liu
- Department of Safety, Health and Environmental Engineering, National Yunlin University of Science and Technology, Yunlin, 64002, Taiwan, ROC.
| | - Hsin-Hui Lin
- Department of Safety, Health and Environmental Engineering, National Yunlin University of Science and Technology, Yunlin, 64002, Taiwan, ROC
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Potential of Variovorax paradoxus isolate BFB1_13 for bioremediation of BTEX contaminated sites. AMB Express 2021; 11:126. [PMID: 34487274 PMCID: PMC8421498 DOI: 10.1186/s13568-021-01289-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 08/29/2021] [Indexed: 12/07/2022] Open
Abstract
Here, we report and discuss the applicability of Variovorax paradoxus strain BFB1_13 in the bioremediation of BTEX contaminated sites. Strain BFB1_13 was capable of degrading all the six BTEX-compounds under both aerobic (O2 conc. 8 mg l−1) and micro-aerobic/oxygen-limited (O2 conc. 0.5 mg l−1) conditions using either individual (8 mg‧l−1) or a mixture of compounds (~ 1.3 mg‧l−1 of each BTEX compound). The BTEX biodegradation capability of SBP-encapsulated cultures (SBP—Small Bioreactor Platform) was also assessed. The fastest degradation rate was observed in the case of aerobic benzene biodegradation (8 mg l−1 per 90 h). Complete biodegradation of other BTEX occurred after at least 168 h of incubation, irrespective of the oxygenation and encapsulation. No statistically significant difference was observed between aerobic and microaerobic BTEX biodegradation. Genes involved in BTEX biodegradation were annotated and degradation pathways were predicted based on whole-genome shotgun sequencing and metabolic analysis. We conclude that V. paradoxus strain BFB1_13 could be used for the development of reactive biobarriers for the containment and in situ decontamination of BTEX contaminated groundwater plumes. Our results suggest that V. paradoxus strain BFB1_13—alone or in co-culture with other BTEX degrading bacterial isolates—can be a new and efficient commercial bioremediation agent for BTEX contaminated sites.
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Lin CW, Liu SH, Wu CF, Chang SH. Critical factors for enhancing the bioremediation of a toxic pollutant at high concentrations in groundwater: Toxicity evaluation, degrader tolerance, and microbial community. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 277:111487. [PMID: 33049609 DOI: 10.1016/j.jenvman.2020.111487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/24/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
Groundwater near refinery and natural gas plants often contain elevated concentrations of toxic sulfolane. Studies on any concentration of sulfolane are limited. Column experiment was conducted to investigate the effects of adding a low dose of H2O2 and nutrient on bioremediation. Vibrio fischeri light inhibition test was used evaluate the toxicity of effluents. The continuous column experiment conditions were sulfolane at 100 mg L-1, dissolved oxygen at 7 mg L-1, absence of phosphorus, and very short hydraulic retention time (7.9 h). A low dose of H2O2 (5.88 mM) enhanced the sulfolane (27.1%) and COD removal (11.8%) in comparison with the control set. Adding nutrient increased bicinchoninic acid protein assay levels, sulfolane removal (99.6%) and COD removal (80.3%). Addition of both H2O2 and nutrient further improved COD removal (90.3%) and COD/sulfolane ratio (0.90) and toxicity removal (Vibrio fischeri light inhibition ratio < 1%). Batch experiment indicated the degraders tolerated sulfolane up to 400 mg L-1. The DGGE method and dendrogram analysis were utilized to investigate the changes of degrader community structure.
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Affiliation(s)
- Chi-Wen Lin
- Department of Safety, Health and Environmental Engineering, National Yunlin University of Science and Technology, Douliu, Yunlin, 64002, Taiwan; National Yunlin University of Science and Technology, Feng Tay Distinguished Professor, Taiwan
| | - Shu-Hui Liu
- Department of Safety, Health and Environmental Engineering, National Yunlin University of Science and Technology, Douliu, Yunlin, 64002, Taiwan
| | - Cheng-Fang Wu
- Department of Safety, Health and Environmental Engineering, National Yunlin University of Science and Technology, Douliu, Yunlin, 64002, Taiwan
| | - Shih-Hsien Chang
- Department of Public Health, Chung-Shan Medical University, Taichung, 402, Taiwan; Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung, 402, Taiwan.
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Mosmeri H, Gholami F, Shavandi M, Dastgheib SMM, Alaie E. Bioremediation of benzene-contaminated groundwater by calcium peroxide (CaO 2) nanoparticles: Continuous-flow and biodiversity studies. JOURNAL OF HAZARDOUS MATERIALS 2019; 371:183-190. [PMID: 30851671 DOI: 10.1016/j.jhazmat.2019.02.071] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 01/25/2019] [Accepted: 02/20/2019] [Indexed: 06/09/2023]
Abstract
Calcium peroxide (CaO2) nanoparticles have been extensively applied in treatment of contaminated groundwater through bioremediation or modified Fenton (MF) processes. In the present study utilization of CaO2 in bioremediation and MF (CaO2+FeSO4) reaction is investigated for benzene (50 mg/L) removal in continuous flow sand-packed columns. The results indicated that MF produced OH radicals markedly increased benzene remediation at first 30 days (up to 93%). But, OH generation rate was gradually declined when the pH was increased and finally 75% of initial benzene removed after 100d. In bioremediation column, because of supplying adequate oxygen by CaO2, the number of planktonic bacteria logarithmically increased to more than 5 × 106 CFU/mL (two orders of magnitude) and consequently 100% benzene removal was achieved by the end of experiment. Scanning electron microscopy analysis visualized the attached biofilm growth on sand surfaces in CaO2 injected columns indicating their key role in the remediation process. The impact of each process on the microbial biodiversity of groundwater was investigated by next generation sequencing (NGS) of the 16S rRNA gene. The alpha and beta analysis indicated that microbial diversity is decreased by CaO2 injection while benzene-degrading species such as Silanimonas, Arthrobacter and Pseudomonas spp. were dominated in remediation column.
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Affiliation(s)
- Hamid Mosmeri
- Ecology and Environmental Pollution Control Research Group, Research Institute of Petroleum Industry, Tehran, Iran
| | - Fatemeh Gholami
- Department of Microbiology, College of Science, University of Tehran, Tehran, Iran
| | - Mahmoud Shavandi
- Ecology and Environmental Pollution Control Research Group, Research Institute of Petroleum Industry, Tehran, Iran.
| | | | - Ebrahim Alaie
- Environment and Biotechnology Research Division, Research Institute of Petroleum Industry, Tehran, Iran
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Liu C, Chen X, Mack EE, Wang S, Du W, Yin Y, Banwart SA, Guo H. Evaluating a novel permeable reactive bio-barrier to remediate PAH-contaminated groundwater. JOURNAL OF HAZARDOUS MATERIALS 2019; 368:444-451. [PMID: 30708346 DOI: 10.1016/j.jhazmat.2019.01.069] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/18/2019] [Accepted: 01/19/2019] [Indexed: 06/09/2023]
Abstract
Permeable reactive barriers (PRBs) are an environmentally-friendly, cost-effective in-situ technology that can be used to remediate polycyclic aromatic hydrocarbons (PAHs)-contaminated groundwater. In this study, PRBs of two different materials (A and B) that relied on microbes self-domestication mechanism were designed and tested. The materials A and B were the same apart from their carbon source: A was based on wheat straw and B was based on coconut shell biochar. We used laboratory batch experiments followed by long-term column tests to assess the capacity of these two materials to remediate PAHs. The results showed that both A and B removed almost 100% of the phenanthrene. More carbon was released from A (80-500 mg/L) than from B (72-195 mg/L), and slightly more oxygen was released from B (7.31-10.31 mg/L) than A (7.15-9.64 mg/L). The release of organic carbon from material B was more stable than that from material A. The bacterial communities of both columns comprised members of the Mycobacterium, Pseudomonas, and Sphingomonas genera that are known to degrade phenanthrene, and Pseudomonas and Sphingomonas were 7 times more abundant in column B than in column A. Material B is more promising for treating PAH-contaminated groundwater than material A.
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Affiliation(s)
- Cuicui Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Xiaohui Chen
- School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - E Erin Mack
- DuPont Corporate Remediation Group, Wilmington, DE, 19805, USA
| | - Shui Wang
- Jiangsu Provincial Academy of Environmental Science, Nanjing, 210036, China
| | - Wenchao Du
- School of the Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Ying Yin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Steven A Banwart
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK; Global Food and Environment Institute, University of Leeds, Leeds, LS2 9JT, UK
| | - Hongyan Guo
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
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Gholami F, Mosmeri H, Shavandi M, Dastgheib SMM, Amoozegar MA. Application of encapsulated magnesium peroxide (MgO 2) nanoparticles in permeable reactive barrier (PRB) for naphthalene and toluene bioremediation from groundwater. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 655:633-640. [PMID: 30476844 DOI: 10.1016/j.scitotenv.2018.11.253] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/16/2018] [Accepted: 11/17/2018] [Indexed: 06/09/2023]
Abstract
One of the challenges in the petroleum hydrocarbon contaminated groundwater remediation by oxygen releasing compounds (ORCs) is to identify the remediation mechanism and determine the impact of ORCs on the environment and the intrinsic groundwater microorganisms. In this research, the application of encapsulated magnesium peroxide (MgO2) nanoparticles in the permeable reactive barrier (PRB) for bioremediation of the groundwater contaminated by toluene and naphthalene was studied in the continuous flow sand-packed plexiglass columns within 50 d experiments. For the biodiversity studies, next generation sequencing (NGS) of the 16S rRNA gene was applied. The results showed that naphthalene was metabolized (within 20 days) faster than toluene (after 30 days) by microorganisms of the aqueous phase. By comparing the contaminant removal in the biotic (which resulted in the complete contaminant removal) and abiotic (around 32% removal for naphthalene and 36% for toluene after 50 d) conditions, the significant role of microorganisms on the decontamination process was proved. Furthermore, the attached microbial communities on the porous media were visualized by scanning electron microscopy (SEM). Microbial community structure analysis by NGS technique revealed that the microbial species which were able to degrade toluene and naphthalene such as P. putida and P. mendocina respectively were stimulated by addition of MgO2 nanoparticles. The presented study resulted in a momentous insight into the application of MgO2 nanoparticles in the hydrocarbon compounds removal from groundwater.
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Affiliation(s)
- Fatemeh Gholami
- Department of Microbiology, College of Science, University of Tehran, Tehran, Iran
| | - Hamid Mosmeri
- Ecology and Environmental Pollution Control Research Group, Research Institute of Petroleum Industry, Tehran, Iran
| | - Mahmoud Shavandi
- Ecology and Environmental Pollution Control Research Group, Research Institute of Petroleum Industry, Tehran, Iran.
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Environmental-Friendly Synthesis of Alkyl Carbamates from Urea and Alcohols with Silica Gel Supported Catalysts. Catalysts 2018. [DOI: 10.3390/catal8120579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
TiO2/SiO2, Cr2O3-NiO/SiO2, and TiO2-Cr2O3/SiO2 were prepared by the impregnation method for alkyl carbamate synthesis using urea as the carbonyl source. Up to 97.5% methyl carbamate yield, 97% ethyl carbamate yield, and 96% butyl carbamate yield could be achieved, respectively. The catalysts were characterized by ICP-AES, BET, XRD, XPS, NH3-TPD, and EPMA. Catalytic activity investigation revealed that TiO2/SiO2, Cr2O3-NiO/SiO2, and TiO2-Cr2O3/SiO2 were effective catalysts for methyl carbamate (MC), ethyl carbamate (EC), and butyl carbamate (BC), respectively. The recycling tests suggested that these silica gel supported catalyst system is active, stable, and reusable. A total of 96–97% alkyl carbamate (methyl, ethyl, and butyl) could be obtained in a 2 L autoclave, and these data suggested that our catalyst system is relatively easy to scale up.
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