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Liu HY, Yu Y, Yu NN, Ding YF, Chen JM, Chen DZ. Airlift two-phase partitioning bioreactor for dichloromethane removal: Silicone rubber stimulated biodegradation and its auto-circulation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 319:115610. [PMID: 35797907 DOI: 10.1016/j.jenvman.2022.115610] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/20/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
Solid non-aqueous phases (NAPs), such as silicone rubber, have been used extensively to improve the removal of volatile organic compounds (VOCs). However, the removal of VOCs is difficult to be further improved because the poor understanding of the mass transfer and reaction processes. Further, the conventional reactors were either complicated or uneconomical. In view of this, herein, an airlift bioreactor with silicone rubber was designed and investigated for dichloromethane (DCM) treatment. The removal efficiency of Reactor 1 (with silicone rubber) was significantly higher than that of Reactor 2 (without silicone rubber), with corresponding higher chloride ion and CO2 production. It was found that Reactor 1 achieved a much better DCM shock tolerance capability and biomass stability than Reactor 2. Silicone rubber not only enhanced the mass transfer in terms of both gas/liquid and gas/microbial phases, but also decreased the toxicity of DCM to microorganisms. Noteworthily, despite the identical inoculum used, the relative abundance of potential DCM-degrading bacteria in Reactor 1 (91.2%) was much higher than that in Reactor 2 (24.3%) at 216 h. Additionally, the silicone rubber could be automatically circulated in the airlift bioreactor due to the driven effect of the airflow, resulting in a significant reduction of energy consumption.
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Affiliation(s)
- Hao-Yang Liu
- School of Petrochemical Engineering and Environment, Zhejiang Ocean University, Zhoushan 316004, China; College of Environment, Zhejiang University of Technology, Hangzhou 310032, China
| | - Yang Yu
- School of Petrochemical Engineering and Environment, Zhejiang Ocean University, Zhoushan 316004, China; Zhejiang Provincial Key Laboratory of Petrochemical Pollution Control, School of Petrochemical Engineering and Environment, Zhejiang Ocean University, Zhoushan 316004, China; National-Local Joint Engineering Laboratory of Harbor Oil & Gas Storage and Transportation Technology, School of Petrochemical Engineering and Environment, Zhejiang Ocean University, Zhoushan, 316022, China.
| | - Ning-Ning Yu
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, China
| | - Yun-Feng Ding
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, China
| | - Jian-Meng Chen
- School of Petrochemical Engineering and Environment, Zhejiang Ocean University, Zhoushan 316004, China; College of Environment, Zhejiang University of Technology, Hangzhou 310032, China; Zhejiang Provincial Key Laboratory of Petrochemical Pollution Control, School of Petrochemical Engineering and Environment, Zhejiang Ocean University, Zhoushan 316004, China; National-Local Joint Engineering Laboratory of Harbor Oil & Gas Storage and Transportation Technology, School of Petrochemical Engineering and Environment, Zhejiang Ocean University, Zhoushan, 316022, China
| | - Dong-Zhi Chen
- School of Petrochemical Engineering and Environment, Zhejiang Ocean University, Zhoushan 316004, China; College of Environment, Zhejiang University of Technology, Hangzhou 310032, China; Zhejiang Provincial Key Laboratory of Petrochemical Pollution Control, School of Petrochemical Engineering and Environment, Zhejiang Ocean University, Zhoushan 316004, China; National-Local Joint Engineering Laboratory of Harbor Oil & Gas Storage and Transportation Technology, School of Petrochemical Engineering and Environment, Zhejiang Ocean University, Zhoushan, 316022, China.
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Fang X, Zhang C, Qian X, Yu D. Self-assembled 2,4-dichlorophenol hydroxylase-inorganic hybrid nanoflowers with enhanced activity and stability. RSC Adv 2018; 8:20976-20981. [PMID: 35542350 PMCID: PMC9080888 DOI: 10.1039/c8ra02360c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 06/01/2018] [Indexed: 12/13/2022] Open
Abstract
2,4-Dichlorophenol hydroxylase (2,4-DCP hydroxylase) is a key enzyme in the degradation of 2,4-dichlorophenoxyacetic acid in the hydroxylation step in many bacteria. Our previous study demonstrated that a cold-adapted 2,4-DCP hydroxylase (tfdB-JLU) exhibits broad substrate specificity for chlorophenols, biphenyl derivatives and their homologues. However, the stability of this enzyme is not satisfactory in practical use. There have been no reports of immobilizing a cold-adapted enzyme to improve its activity and stability so far. This study for the first time reports a facile approach for the synthesis of hybrid nanoflowers (hNFs) formed from cold-adapted 2,4-dichlorophenol hydroxylase (tfdB-JLU) and Cu3(PO4)2·3H2O. The influence of experimental factors, such as the pH of the solution mixture and the enzyme and Cu2+ concentrations, on the activity of the prepared tfdB-JLU-hNFs is investigated. The morphologies of the tfdB-JLU-hNFs are further analyzed by SEM and TEM. Compared to the free enzyme, the tfdB-JLU-hNFs exhibit up to 162.46 ± 1.53% enhanced 2,4-dichlorophenol degradation activity when encapsulated at different enzyme concentrations. The tfdB-JLU-hNFs exhibit excellent durability with 58.34% residual activity after six successive cycles, and up to 90.58% residual activity after 20 days of storage. These results demonstrate that this multistage and hierarchical flower-like structure can effectively increase enzyme activity and stability with respect to those of the free enzyme. The satisfactory removal rate of 2,4-dichlorophenol catalyzed by tfdB-JLU-hNFs suggests that this immobilized enzyme exhibits great potential for application in bioremediation. Highly stable and active hydroxylase-inorganic hybrid nanoflowers with great potential for application in bioremediation were obtained.![]()
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Affiliation(s)
- Xuexun Fang
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education
- College of Life Science
- Jilin University
- Changchun
- P. R. China
| | - Chengkai Zhang
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education
- College of Life Science
- Jilin University
- Changchun
- P. R. China
| | - Xue Qian
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education
- College of Life Science
- Jilin University
- Changchun
- P. R. China
| | - Dahai Yu
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education
- College of Life Science
- Jilin University
- Changchun
- P. R. China
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Lu Q, de Toledo RA, Xie F, Li J, Shim H. Reutilization of waste scrap tyre as the immobilization matrix for the enhanced bioremoval of a monoaromatic hydrocarbons, methyl tert-butyl ether, and chlorinated ethenes mixture from water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 583:88-96. [PMID: 28109662 DOI: 10.1016/j.scitotenv.2017.01.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 01/01/2017] [Accepted: 01/04/2017] [Indexed: 06/06/2023]
Abstract
BTEX (benzene, toluene, ethylbenzene, ortho-, meta-, and para-xylenes), methyl tert-butyl ether (MTBE), cis-1,2-dichloroethylene (cis-DCE), and trichloroethylene (TCE) are among the major soil and groundwater contaminants frequently co-existing, as a result of their widespread uses. Pseudomonas plecoglossicida was immobilized on waste scrap tyre to remove these contaminants mixture from synthetic contaminated water. The microbial activity was enhanced in the immobilized system, shown by the higher colony forming units (CFUs) (40%), while BTEX were used as growth substrates. The adsorption capacity of tyres toward contaminants reached a maximum within one day, with BTEX (76.3%) and TCE (64.3%) showing the highest sorption removal capacities, followed by cis-DCE (30.0%) and MTBE (11.0%). The adsorption data fitted the Freundlich isotherm with a good linear correlation (0.989-0.999) for the initial contaminants concentration range applied (25-125mg/L). The monoaromatic hydrocarbons were almost completely removed in the immobilized system and the favourable removal efficiencies of 78% and 90% were obtained for cis-DCE and TCE, respectively. The hybrid (biological, immobilization/physical, sorption) system was further evaluated with the contaminants spiked intermittently for the stable performance. The addition of mineral salt medium further enhanced the bioremoval of contaminants by stimulating the microbial growth to some extent.
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Affiliation(s)
- Qihong Lu
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR 999078, China; School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
| | - Renata Alves de Toledo
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR 999078, China
| | - Fei Xie
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR 999078, China; Shanxi Academy for Environmental Planning, Taiyuan 030002, China
| | - Junhui Li
- College of Natural Resources and Environmental Science, South China Agricultural University, Guangzhou 510642, China
| | - Hojae Shim
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR 999078, China.
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Tomei MC, Mosca Angelucci D, Daugulis AJ. A novel continuous two-phase partitioning bioreactor operated with polymeric tubing: Performance validation for enhanced biological removal of toxic substrates. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2017; 187:265-272. [PMID: 27912137 DOI: 10.1016/j.jenvman.2016.11.045] [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: 07/08/2016] [Revised: 11/16/2016] [Accepted: 11/20/2016] [Indexed: 06/06/2023]
Abstract
A continuous two-phase partitioning bioreactor (C-TPPB), operated with coiled tubing made of the DuPont polymer Hytrel 8206, was tested for the bioremediation of 4-chlorophenol, as a model toxic compound. The tubing was immersed in the aqueous phase, with the contaminated water flowing tube-side, and an adapted microbial culture suspended in the bioreactor itself, with the metabolic demand of the cells creating a concentration gradient to cause the substrate to diffuse into the bioreactor for biodegradation. The system was operated over a range of loadings (tubing influent concentration 750-1500 mg L-1), with near-complete substrate removal in all cases. Distribution of the contaminant at the end of the tests (96 h) highlighted biological removal in the range of 87-95%, while the amount retained in the polymer ranged from ∼1 to 8%. Mass transfer of the substrate across the tubing wall was not limiting, and the polymer demonstrated the capacity to buffer the substrate loadings and to adapt to microbial metabolism. The impact of C-TPPB operation on biomass activity was also investigated by a kinetic characterization of the microbial culture, which showed better resistance to substrate inhibition after C-TPPB operation, thereby confirming the beneficial effect of sub-inhibitory controlled conditions, characteristic of TPPB systems.
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Affiliation(s)
- M Concetta Tomei
- Water Research Institute, C.N.R., Via Salaria km 29.300, CP 10, 00015 Monterotondo Stazione, Rome, Italy.
| | - Domenica Mosca Angelucci
- Water Research Institute, C.N.R., Via Salaria km 29.300, CP 10, 00015 Monterotondo Stazione, Rome, Italy
| | - Andrew J Daugulis
- Department of Chemical Engineering, Queen's University, Kingston, Ontario K7L 3N6, Canada
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5
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Tomei MC, Mosca Angelucci D, Daugulis AJ. Sequential anaerobic-aerobic decolourization of a real textile wastewater in a two-phase partitioning bioreactor. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 573:585-593. [PMID: 27580470 DOI: 10.1016/j.scitotenv.2016.08.140] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/02/2016] [Accepted: 08/19/2016] [Indexed: 06/06/2023]
Abstract
This work describes the application of a solid-liquid two-phase partitioning bioreactor (TPPB) for the removal of colour from a real textile wastewater containing reactive azo-dyes. Four polymers were tested over the pH range of 4-9 to select the most effective absorbant to be used as the partitioning phase in the TPPB. The best results were obtained with Hytrel 8206 at pH4 achieving ~70% colour removal, based on the dominant wavelength, in the first 5h of contact time, and 84% after 24h. Wastewater treatment was undertaken in a solid-liquid TPPB operated with Hytrel 8206 in sequential anaerobic-aerobic configuration. The reaction time of 23h was equally distributed between the anaerobic and aerobic phases and, to favour colour uptake, the pH was controlled at 4.5 in the first 4h of the anaerobic phase, and then increased to 7.5. Colour removal (for the dominant wavelength, 536nm) increased from 70 to 85% by modifying the bioreactor operation from single-phase to TPPB mode. Based on COD measurements nearly complete biodegradation of the intermediates produced in the anaerobic phase was obtained, both in the single-phase and two-phase mode, with better performance of the TPPB system reaching 75% CODDye removal.
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Affiliation(s)
- M Concetta Tomei
- Water Research Institute, C.N.R., Via Salaria km 29.300, CP 10, 00015, Monterotondo Stazione, Rome, Italy.
| | - Domenica Mosca Angelucci
- Water Research Institute, C.N.R., Via Salaria km 29.300, CP 10, 00015, Monterotondo Stazione, Rome, Italy
| | - Andrew J Daugulis
- Department of Chemical Engineering, Queen's University, Kingston, Ontario K7L 3N6, Canada
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Tomei MC, Mosca Angelucci D, Daugulis AJ. Towards a continuous two-phase partitioning bioreactor for xenobiotic removal. JOURNAL OF HAZARDOUS MATERIALS 2016; 317:403-415. [PMID: 27318737 DOI: 10.1016/j.jhazmat.2016.05.092] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/08/2016] [Accepted: 05/31/2016] [Indexed: 06/06/2023]
Abstract
The removal of a xenobiotic (4-chlorophenol) from contaminated water was investigated in a simulated continuous two-phase partitioning bioreactor (C-TPPB), fitted with coiled tubing comprised of a specifically-selected extruded polymer, Hytrel 8206. Wastewater flowed inside the tubing, the pollutant diffused through the tubing wall, and was removed in the aqueous bioreactor phase at typical biological removal rates in the C-TTPB simulated by varying aqueous phase throughput to the reactor. Operating over a range of influent substrate concentrations (500-1500mgL(-1)) and hydraulic retention times in the tubing (4-8h), overall mass transfer coefficients were 1.7-3.5×10(-7)ms(-1), with the highest value corresponding to the highest tubing flow rate. Corresponding mass transfer rates are of the same order as biological removal rates, and thus do not limit the removal process. The C-TPPB showed good performance over all organic and hydraulic loading ranges, with removal efficiencies of 4CP in the tubing wastewater stream always ≥96%. Additionally, the presence of the Hytrel tubing was able to buffer increases in organic loading to the hybrid system, enhancing overall process stability. Biological testing of the C-TPPB confirmed the abiotic test results demonstrating even higher 4-chlorophenol removal efficiency (∼99%) in the tubing stream.
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Affiliation(s)
- M Concetta Tomei
- Water Research Institute, C.N.R., Via Salaria km 29.300, CP 10, 00015 Monterotondo Stazione, Rome, Italy.
| | - Domenica Mosca Angelucci
- Water Research Institute, C.N.R., Via Salaria km 29.300, CP 10, 00015 Monterotondo Stazione, Rome, Italy
| | - Andrew J Daugulis
- Department of Chemical Engineering, Queen's University, Kingston, Ontario K7L 3N6, Canada
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Lu Q, de Toledo RA, Xie F, Li J, Shim H. Combined removal of a BTEX, TCE, and cis-DCE mixture using Pseudomonas sp. immobilized on scrap tyres. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:14043-14049. [PMID: 25956516 DOI: 10.1007/s11356-015-4644-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 04/30/2015] [Indexed: 06/04/2023]
Abstract
The simultaneous aerobic removal of a mixture of benzene, toluene, ethylbenzene, and o,m,p-xylene (BTEX); cis-dichloroethylene (cis-DCE); and trichloroethylene (TCE) from the artificially contaminated water using an indigenous bacterial isolate identified as Pseudomonas plecoglossicida immobilized on waste scrap tyres was investigated. Suspended and immobilized conditions were compared for the removal of these volatile organic compounds. For the immobilized system, toluene, benzene, and ethylbenzene were completely removed, while the highest removal efficiencies of 99.0 ± 0.1, 96.8 ± 0.3, 73.6 ± 2.5, and 61.6 ± 0.9% were obtained for o-xylene, m,p-xylene, TCE, and cis-DCE, respectively. The sorption kinetics of contaminants towards tyre surface was also evaluated, and the sorption capacity generally followed the order of toluene > benzene > m,p-xylene > o-xylene > ethylbenzene > TCE > cis-DCE. Scrap tyres showed a good capability for the simultaneous sorption and bioremoval of BTEX/cis-DCE/TCE mixture, implying a promising waste material for the removal of contaminant mixture from industrial wastewater or contaminated groundwater.
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Affiliation(s)
- Qihong Lu
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau, SAR, 999078, China
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Ren H, Li Q, Zhan Y, Fang X, Yu D. 2,4-Dichlorophenol hydroxylase for chlorophenol removal: Substrate specificity and catalytic activity. Enzyme Microb Technol 2015; 82:74-81. [PMID: 26672451 DOI: 10.1016/j.enzmictec.2015.08.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/11/2015] [Accepted: 08/11/2015] [Indexed: 10/23/2022]
Abstract
Chlorophenols (CPs) are common environmental pollutants. As such, different treatments have been assessed to facilitate their removal. In this study, 2,4-dichlorophenol (2,4-DCP) hydroxylase was used to systematically investigate the activity and removal ability of 19CP congeners at 25 and 0 °C. Results demonstrated that 2,4-DCP hydroxylase exhibited a broad substrate specificity to CPs. The activities of 2,4-DCP hydroxylase against specific CP congeners, including 3-CP, 2,3,6-trichlorophenol, 2-CP, and 2,3-DCP, were higher than those against 2,4-DCP, which is the preferred substrate of previously reported 2,4-DCP hydroxylase. To verify whether cofactors are necessary to promote hydroxylase activity against CP congeners, we added FAD and found that the added FAD induced a 1.33-fold to 5.13-fold significant increase in hydroxylase activity against different CP congeners. The metabolic pathways of the CP degradation in the enzymatic hydroxylation step were preliminarily proposed on the basis of the analyses of the enzymatic activities against 19CP congeners. We found that the high activity and removal rate of 2,4-DCP hydroxylase against CPs at 0 °C enhance the low-temperature-adaptability of this enzyme to the CP congeners; as such, the proposed removal process may be applied to biochemical, bioremediation, and industrial processes, particularly in cold environments.
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Affiliation(s)
- Hejun Ren
- Key Laboratory of Ground Water Resources and Environment of the Ministry of Education, College of Environment and Resources, Jilin University, 2519 Jiefang Road, Changchun 130021, PR China
| | - Qingchao Li
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, College of Life Science, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China
| | - Yang Zhan
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, College of Life Science, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China
| | - Xuexun Fang
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, College of Life Science, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China
| | - Dahai Yu
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, College of Life Science, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
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Mosca Angelucci D, Tomei MC. Regeneration strategies of polymers employed in ex-situ remediation of contaminated soil: Bioregeneration versus solvent extraction. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2015; 159:169-177. [PMID: 26074469 DOI: 10.1016/j.jenvman.2015.05.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 05/13/2015] [Accepted: 05/15/2015] [Indexed: 06/04/2023]
Abstract
In this study we evaluated the feasibility of two regeneration strategies of contaminated polymers employed for ex-situ soil remediation in a two-step process. Soil decontamination is achieved by sorption of the pollutants on the polymer beads, which are regenerated in a subsequent step. Tested soil was contaminated with a mixture of 4-chlorophenol and pentachlorophenol, and a commercial polymer, Hytrel, has been employed for extraction. Removal efficiencies of the polymer-soil extraction are in the range of 51-97% for a contact time ≤ 24 h. Two polymer regeneration strategies, solvent extraction and biological regeneration (realized in a two-phase partitioning bioreactor), were tested and compared. Performance was assessed in terms of removal rates and efficiencies and an economic analysis based on the operating costs has been performed. Results demonstrated the feasibility of both regeneration strategies, but the bioregeneration was advantageous in that provided the biodegradation of the contaminants desorbed from the polymer. Practically complete removal for 4-chlorophenol and up to 85% biodegradation efficiency for pentachlorophenol were achieved. Instead, in the solvent extraction, a relevant production (184-831 L kg(pol)(-1)) of a highly polluted stream to be treated or disposed of is observed. The cost analysis of the two strategies showed that the bioregeneration is much more convenient with operating costs of ∼12 €/kg(pol) i.e. more than one order of magnitude lower in comparison to ∼233 €/kg(pol) of the solvent extraction.
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Affiliation(s)
- Domenica Mosca Angelucci
- Water Research Institute, C.N.R., Via Salaria km 29.300, CP 10, 00015, Monterotondo Stazione, Rome, Italy
| | - M Concetta Tomei
- Water Research Institute, C.N.R., Via Salaria km 29.300, CP 10, 00015, Monterotondo Stazione, Rome, Italy.
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Angelucci DM, Tomei MC. Pentachlorophenol aerobic removal in a sequential reactor: start-up procedure and kinetic study. ENVIRONMENTAL TECHNOLOGY 2015; 36:327-335. [PMID: 25514134 DOI: 10.1080/09593330.2014.946099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This study has demonstrated the applicability of a simple technology such as the sequencing batch reactor (SBR), operated with suspended biomass, to the aerobic biodegradation of a highly toxic compound, the pentachlorophenol (PCP). An enrichment of a microbial consortium, originated from the biomass of an urban wastewater treatment plant, was performed and 70 days were sufficient to achieve removal efficiencies of ∼90% with the compound fed as only carbon and energy source Once completed the start-up period, the SBR was operated with the acclimatized biomass for 60 days at a feed concentration of PCP in the range of 10-20 mg L(-1). Improved performance was observed at increased influent concentration and the reached removal efficiency for the highest concentrations was stable at values≥90%. Kinetic and stoichiometric characterization of the acclimated biomass was performed with biodegradation tests carried out in the bioreactor during the reaction phase. The classical and a modified four-parameter forms of the Haldane equation were applied to model the substrate inhibited kinetics. Both models provided reliable predictions with high correlation coefficients (>0.99). The biomass characterization was completed with the evaluation of the growth yield coefficient, Y (0.075 on chemical oxygen demand base) and endogenous respiration rate, b (0.054 d(-1)). The aerobic SBR, operated in the metabolic mode with a mixed culture, showed superior performance in comparison to continuous systems applied in the same range of PCP influent loads and achieved removal rates are suitable for application.
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Affiliation(s)
- Domenica Mosca Angelucci
- a Water Research Institute, C.N.R ., Via Salaria km 29.300, CP 10 - 00015 Monterotondo Stazione, Rome , Italy
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Ren H, Zhan Y, Fang X, Yu D. Enhanced catalytic activity and thermal stability of 2,4-dichlorophenol hydroxylase by using microwave irradiation and imidazolium ionic liquid for 2,4-dichlorophenol removal. RSC Adv 2014. [DOI: 10.1039/c4ra10637g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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