1
|
Ri C, Li F, Mun H, Liu L, Tang J. Impact of different zero valent iron-based particles on anaerobic microbial dechlorination of 2,4-dichlorophenol: Comparison of dechlorination performance and the underlying mechanism. JOURNAL OF HAZARDOUS MATERIALS 2023; 458:131881. [PMID: 37379603 DOI: 10.1016/j.jhazmat.2023.131881] [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: 01/27/2023] [Revised: 05/14/2023] [Accepted: 06/15/2023] [Indexed: 06/30/2023]
Abstract
The integration of iron-based materials and anaerobic microbial consortia has been extensively studied owing to its potential to enhance pollutant degradation. However, few studies have compared how different iron materials enhance the dechlorination of chlorophenols in coupled microbial systems. This study systematically compared the combined performances of microbial community (MC) and iron materials (Fe0/FeS2 +MC, S-nZVI+MC, n-ZVI+MC, and nFe/Ni+MC) for the dechlorination of 2,4-dichlorophenol (DCP) as one representative of chlorophenols. DCP dechlorination rate was significantly higher in Fe0/FeS2 +MC and S-nZVI+MC (1.92 and 1.67 times, with no significant difference between two groups) than in nZVI+MC and nFe/Ni+MC (1.29 and 1.25 times, with no significant difference between two groups). Fe0/FeS2 had better performance for the reductive dechlorination process as compared with other three iron-based materials via the consumption of any trace amount of oxygen in anoxic condition and accelerated electron transfer. On the other hand, nFe/Ni could induce different dechlorinating bacteria as compared to other iron materials. The enhanced microbial dechlorination was mainly due to some putative dechlorinating bacteria (Pseudomonas, Azotobacter, Propionibacterium), and due to improved electron transfer of sulfidated iron particles. Therefore, Fe0/FeS2 as a biocompatible as well as low-cost sulfidated material can be a good alternative for possible engineering applications in groundwater remediation.
Collapse
Affiliation(s)
- Cholnam Ri
- MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Institute of Microbiology, State Academy of Sciences, Pyongyang, Democratic People's Republic of Korea
| | - Fengxiang Li
- MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Hyokchol Mun
- MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Institute of national energy, State Academy of Sciences, Pyongyang, Democratic People's Republic of Korea
| | - Linan Liu
- MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Jingchun Tang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
| |
Collapse
|
2
|
Dinh MTN, Nguyen VT, Nguyen LTH. The potential application of carbazole-degrading bacteria for dioxin bioremediation. BIORESOUR BIOPROCESS 2023; 10:56. [PMID: 38647625 PMCID: PMC10992316 DOI: 10.1186/s40643-023-00680-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 08/17/2023] [Indexed: 04/25/2024] Open
Abstract
Extensive research has been conducted over the years on the bacterial degradation of dioxins and their related compounds including carbazole, because these chemicals are highly toxic and has been widely distributed in the environment. There is a pressing need to explore and develop more bacterial strains with unique catabolic features to effectively remediate dioxin-polluted sites. Carbazole has a chemical structure similar to dioxins, and the degradation pathways of these two chemicals are highly homologous. Some carbazole-degrading bacterial strains have been demonstrated to have the ability to degrade dioxins, such as Pseudomonas sp. strain CA10 và Sphingomonas sp. KA1. The introduction of strain KA1 into dioxin-contaminated model soil resulted in the degradation of 96% and 70% of 2-chlorodibenzo-p-dioxin (2-CDD) and 2,3-dichlorodibenzo-p-dioxin (2,3-DCDD), respectively, after 7-day incubation period. These degradation rates were similar to those achieved with strain CA10, which removed 96% of 2-CDD and 80% of 2,3-DCDD from the same model soil. Therefore, carbazole-degrading bacteria hold significant promise as potential candidates for dioxin bioremediation. This paper overviews the connection between the bacterial degradation of dioxins and carbazole, highlighting the potential for dioxin biodegradation by carbazole-degrading bacterial strains.
Collapse
Affiliation(s)
- Mai Thi Ngoc Dinh
- Faculty of Biotechnology, Chemistry and Environmental Engineering, Phenikaa University, A9 Building, Nguyen Van Trac Street, Ha Dong District, Hanoi, Vietnam.
- Bioresource Research Center, Phenikaa University, Hanoi, Vietnam.
| | - Van Thi Nguyen
- VNU Institute of Microbiology and Biotechnology, Vietnam National University, E2 Building, 144 Xuan Thuy Street, Cau Giay District, Hanoi, Vietnam
| | - Ly Thi Huong Nguyen
- Department of Physiology, College of Korean Medicine, Dongguk University, Gyeongju, Republic of Korea
| |
Collapse
|
3
|
Chen WY, Wu JH, Wang BN. Intermittent Oxygen Supply Facilitates Codegradation of Trichloroethene and Toluene by Anaerobic Consortia. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023. [PMID: 37422855 DOI: 10.1021/acs.est.3c02481] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Biodegradation is commonly employed for remediating trichloroethene- or toluene-contaminated sites. However, remediation methods using either anaerobic or aerobic degradation are inefficient for dual pollutants. We developed an anaerobic sequencing batch reactor system with intermittent oxygen supply for the codegradation of trichloroethylene and toluene. Our results showed that oxygen inhibited anaerobic dechlorination of trichloroethene, but dechlorination rates remained comparable to that at dissolved oxygen levels of 0.2 mg/L. Intermittent oxygenation engendered reactor redox fluctuations (-146 to -475 mV) and facilitated rapid codegradation of targeting dual pollutants, with trichloroethene degradation constituting only 27.5% of the noninhibited dechlorination. Amplicon sequencing analysis revealed the predominance of Dehalogenimonas (16.0% ± 3.5%) over Dehalococcoides (0.3% ± 0.2%), with ten times higher transcriptomic activity in Dehalogenimonas. Shotgun metagenomics revealed numerous genes related to reductive dehalogenases and oxidative stress resistance in Dehalogenimonas and Dehalococcoides, as well as the enrichment of diversified facultative populations with functional genes related to trichloroethylene cometabolism and aerobic and anaerobic toluene degradation. These findings suggested that the codegradation of trichloroethylene and toluene may involve multiple biodegradation mechanisms. Overall results of this study demonstrate the effectiveness of intermittent micro-oxygenation in aiding trichloroethene-toluene degradation, suggesting the potential for the bioremediation of sites with similar organic pollutants.
Collapse
Affiliation(s)
- Wei-Yu Chen
- Department of Environmental Engineering, National Cheng Kung University, No. 1, University Rd., East District, Tainan City 70101, Taiwan
| | - Jer-Horng Wu
- Department of Environmental Engineering, National Cheng Kung University, No. 1, University Rd., East District, Tainan City 70101, Taiwan
| | - Bing Nan Wang
- Department of Environmental Engineering, National Cheng Kung University, No. 1, University Rd., East District, Tainan City 70101, Taiwan
- Environmental Laboratory and Research, Sinotech Environmental Technology, Ltd., No. 351, Sanzhong Rd., Dashe District, Kaohsiung City 815040, Taiwan
| |
Collapse
|
4
|
Saibu S, Adebusoye SA, Oyetibo GO. Soil microbiome response to 2-chlorodibenzo-p-dioxin during bioremediation of contaminated tropical soil in a microcosm-based study. JOURNAL OF HAZARDOUS MATERIALS 2023; 451:131105. [PMID: 36893594 DOI: 10.1016/j.jhazmat.2023.131105] [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: 12/28/2022] [Revised: 02/17/2023] [Accepted: 02/26/2023] [Indexed: 06/18/2023]
Abstract
A pristine soil was artificially contaminated with 2-chlorodibenzo-p-dioxin (2-CDD) and separated into three portions. Microcosms SSOC and SSCC were seeded with Bacillus sp. SS2 and a three-member bacterial consortium respectively; SSC was untreated, while heat-sterilized contaminated soil served as overall control. Significant degradation of 2-CDD occurred in all microcosms except for the control where the concentration remained unchanged. Degradation of 2-CDD was highest in SSCC (94.9%) compared to SSOC (91.66%) and SCC (85.9%). There was also a notable reduction in the microbial composition complexity both in species richness and evenness following dioxin contamination, a trend that nearly lasted the study period; particularly in setups SSC and SSOC. Irrespective of the bioremediation strategies, the soil microflora was practically dominated by the Firmicutes and at the genus level, the phylotype Bacillus was the most dominant. Other dominant taxa though negatively impacted were Proteobacteria, Actinobacteria, Chloroflexi, and Acidobacteria. Overall, this study demonstrated the feasibility of microbial seeding as an effective strategy to cleanup tropical soil contaminated with dioxins and the importance of metagenomics in elucidating the microbial diversities of contaminated soils. Meanwhile, the seeded organisms, owed their success not only to metabolic competence, but survivability, adaptability and ability to compete favourably with autochthonous microflora.
Collapse
Affiliation(s)
- Salametu Saibu
- Department of Microbiology, University of Lagos, Akoka, Lagos, Nigeria; Department of Microbiology, Lagos State University, Ojo, Lagos, Nigeria.
| | | | - Ganiyu O Oyetibo
- Department of Microbiology, University of Lagos, Akoka, Lagos, Nigeria.
| |
Collapse
|
5
|
A Review of Soil Contaminated with Dioxins and Biodegradation Technologies: Current Status and Future Prospects. TOXICS 2022; 10:toxics10060278. [PMID: 35736887 PMCID: PMC9227754 DOI: 10.3390/toxics10060278] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/23/2022] [Accepted: 05/23/2022] [Indexed: 12/05/2022]
Abstract
This article provides a comprehensive assessment of dioxins contaminating the soil and evaluates the bioremediation technology currently being widely used, and also offers recommendations for future prospects. Soil pollution containing dioxins is extremely toxic and hazardous to human health and the environment. Dioxin concentrations in soils around the world are caused by a variety of sources and outcomes, but the main sources are from the consequences of war and human activities. Bioremediation technology (bioaugmentation, biostimulation, and phytoremediation) is considered an optimal and environmentally friendly technology, with the goal of applying native microbial communities and using plant species with a high biomass to treat contaminated dioxins in soil. The powerful bioremediation system is the growth of microorganisms that contribute to the increased mutualistic and competitive relationships between different strains of microorganisms. Although biological treatment technology can thoroughly treat contaminated dioxins in soil with high efficiency, the amount of gas generated and Cl radicals dispersed after the treatment process remains high. Further research on the subject is required to provide stricter control over the outputs noted in this study.
Collapse
|
6
|
Yousaf U, Ali Khan AH, Farooqi A, Muhammad YS, Barros R, Tamayo-Ramos JA, Iqbal M, Yousaf S. Interactive effect of biochar and compost with Poaceae and Fabaceae plants on remediation of total petroleum hydrocarbons in crude oil contaminated soil. CHEMOSPHERE 2022; 286:131782. [PMID: 34375825 DOI: 10.1016/j.chemosphere.2021.131782] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/27/2021] [Accepted: 08/01/2021] [Indexed: 06/13/2023]
Abstract
The current study was dedicated to finding the effect of soil amendments (biochar and compost) on plants belonging to Poaceae and Fabaceae families. Plants selected for the phytoremediation experiment included wheat (Triticum aestivum), maize (Zea mays), white clover (Trifolium repens), alfalfa (Medicago sativa), and ryegrass (Lolium multiflorum). The physiological and microbial parameters of plants and soil were affected negatively by the 4 % TPHs soil contamination. The studied physiological parameters were fresh and dried biomass, root and shoot length, and chlorophyll content. Microbial parameters included root and shoot endophytic count. Soil parameters included rhizospheric CFUs and residual TPHs. Biochar with wheat, maize, and ryegrass (Fabaceae family) and compost with white clover and alfalfa (Poaceae family) improved plant growth parameters and showed better phytoremediation of TPHs. Among different plants, the highest TPH removal (68.5 %) was demonstrated by ryegrass with compost, followed by white clover with biochar (68 %). Without any soil amendment, ryegrass and alfalfa showed 59.55 and 35.21 % degradation of TPHs, respectively. Biochar and compost alone removed 27.24 % and 6.01 % TPHs, respectively. The interactive effect of soil amendment and plant type was also noted for studied parameters and TPHs degradation.
Collapse
Affiliation(s)
- Uzma Yousaf
- Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| | - Aqib Hassan Ali Khan
- Department of Earth & Environmental Sciences, Bahria University (Karachi Campus), Karachi, 75260, Pakistan
| | - Asifa Farooqi
- Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| | - Yousaf Shad Muhammad
- Department of Statistics, Faculty of Natural Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| | - Rocío Barros
- International Research Center in Critical Raw Materials and Advanced Industrial Technologies, Universidad de Burgos, Burgos, 09001, Spain
| | - Juan Antonio Tamayo-Ramos
- International Research Center in Critical Raw Materials and Advanced Industrial Technologies, Universidad de Burgos, Burgos, 09001, Spain
| | - Mazhar Iqbal
- Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| | - Sohail Yousaf
- Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
| |
Collapse
|
7
|
Nguyen BAT, Hsieh JL, Lo SC, Wang SY, Hung CH, Huang E, Hung SH, Chin WC, Huang CC. Biodegradation of dioxins by Burkholderia cenocepacia strain 869T2: Role of 2-haloacid dehalogenase. JOURNAL OF HAZARDOUS MATERIALS 2021; 401:123347. [PMID: 33113713 DOI: 10.1016/j.jhazmat.2020.123347] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 06/10/2020] [Accepted: 06/28/2020] [Indexed: 06/11/2023]
Abstract
Dioxin compounds are persistent carcinogenic byproducts of anthropogenic activities such as waste combustion and other industrial activities. The ubiquitous distribution of dioxins is global concerns these days. Among of recent techniques, bioremediation, an eco-friendly and cost-effective technology, uses bacteria or fungi to detoxify in dioxins; however, not many bacteria can degrade the most toxic dioxin congener 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD). In this study, the endophytic bacterium Burkholderia cenocapacia 869T2 was capable of TCDD degradation by nearly 95 % after one-week of an aerobic incubation. Through transcriptomic analysis of the strain 869T2 at 6 -h and 12 -h TCDD exposure, a number of catabolic genes involved in dioxin metabolism were detected with high gene expressions in the presence of TCDD. The transcriptome data also indicated that B. cenocepacia strain 869T2 metabolized the dioxin compounds from an early phase (at 6 h) of the incubation, and the initial outline for a general dioxin degradation pathway were proposed. One of the catabolic genes, l-2-haloacid dehalogenase (2-HAD) was cloned to investigate its contribution in dioxin dehalogenation. By detecting the increasing concentration of chloride ions released from TCDD, our results indicated that the dehalogenase played a crucial role in dehalogenation of dioxin in the aerobic condition.
Collapse
Affiliation(s)
- Bao-Anh Thi Nguyen
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, Republic of China; Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Ju-Liang Hsieh
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, Republic of China
| | - Shou-Chen Lo
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, Republic of China
| | - Sui-Yuan Wang
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, Republic of China
| | - Chun-Hsiung Hung
- Department of Environmental Engineering, National Chung Hsing University, Taichung, Taiwan, Republic of China
| | - Eugene Huang
- College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, Taiwan, Republic of China
| | - Shih-Hsun Hung
- Department of Horticulture, National Chung Hsing University, Taichung, Taiwan, Republic of China
| | - Wei-Chih Chin
- General Research Service Center, National Pingtung University of Science and Technology, Pingtung, Taiwan, Republic of China; Department of Biological Sciences and Technology, National Pingtung University of Science and Technology, Pingtung, Taiwan, Republic of China.
| | - Chieh-Chen Huang
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, Republic of China.
| |
Collapse
|
8
|
Girardot F, Allégra S, Pfendler S, Conord C, Rey C, Gillet B, Hughes S, Bouchardon AE, Hua A, Paran F, Bouchardon JL, Faure O. Bacterial diversity on an abandoned, industrial wasteland contaminated by polychlorinated biphenyls, dioxins, furans and trace metals. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 748:141242. [PMID: 32827890 DOI: 10.1016/j.scitotenv.2020.141242] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/22/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
Most former industrial sites are contaminated by mixtures of trace elements and organic pollutants. Levels of pollutants do not provide information regarding their biological impact, bioavailability and possible interactions between substances. There is genuine interest in combining chemical analyses with biological investigations. We studied a brownfield where several industrial activities were carried out starting in the 1970s, (incineration of pyralene transformers, recovery of copper by burning cables in the open air). Four representative plots showing different levels of polychlorobiphenyls were selected. Organic and trace metal levels were measured together with soil pedological characteristics. The bacterial community structure and functional diversity were assessed by 16S metagenomics with deep sequencing and community-level physiological profiling. Additionally, a vegetation survey was performed. Polychlorobiphenyls (8 mg.kg-1 to 1500 mg.kg-1) were from 2.4 × 103-fold to 6 × 105-fold higher than the European background level of 2.5 μg.kg-1. Polychlorinated dibenzo-p-dioxins and dibenzofurans ranged from 0.5 to 8.0 μg.kg-1. The soil was also contaminated with trace metals, i.e., Cu > 187, Zn > 217 and Pb > 372 mg.kg-1. Location within the study area, trace metal content and soil humidity were stronger determinants than organic pollutants of bacterial community structures and activities. Thus, the highest biological activity and the greatest bacteriological richness were observed in the plot that was less contaminated with trace metals, despite the high level of organic pollutants in the plot. Moreover, trace element pollution was associated with a relatively low presence of Actinobacteria and Rhizobia. The plot with the highest metal contamination was rich in metal-resistant bacteria such as Sphingomonadales, Geodermatophilaceae and KD4-96 (Chloroflexi phylum). Acidobacteria and Sphingomonadales, capable of resisting trace metals and degrading persistent organic pollutants, were dominant in the plots that had accumulated metal and organic contamination, but bacterial activity was lower in these plots than in the other plots.
Collapse
Affiliation(s)
- Françoise Girardot
- Université de Lyon, Université Jean Monnet Saint-Etienne, CNRS, EVS-ISTHME UMR 5600, F-42023 Saint-Étienne, France; Université de Lyon, Université Jean Monnet Saint-Etienne, Institut Universitaire de Technologie, F-42023 Saint- Étienne, France.
| | - Séverine Allégra
- Université de Lyon, Université Jean Monnet Saint-Etienne, CNRS, EVS-ISTHME UMR 5600, F-42023 Saint-Étienne, France; Université de Lyon, Université Jean Monnet Saint-Etienne, Institut Universitaire de Technologie, F-42023 Saint- Étienne, France
| | - Stéphane Pfendler
- Université de Lyon, Université Jean Monnet Saint-Etienne, CNRS, EVS-ISTHME UMR 5600, F-42023 Saint-Étienne, France
| | - Cyrille Conord
- Université de Lyon, Université Jean Monnet Saint-Etienne, CNRS, EVS-ISTHME UMR 5600, F-42023 Saint-Étienne, France
| | - Carine Rey
- Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon (ENSL), Laboratoire de Biologie et Modélisation de la Cellule, CNRS UMR 5239, F-69634 Lyon, France; Master de Biologie, ENSL, Université Claude Bernard Lyon I, Université de Lyon, F-69342 Lyon, France
| | - Benjamin Gillet
- Université de Lyon, Université Claude Bernard Lyon 1, ENSL, CNRS, Institut de Génomique Fonctionnelle de Lyon, UMR 5242, F-69007 Lyon, France
| | - Sandrine Hughes
- Université de Lyon, Université Claude Bernard Lyon 1, ENSL, CNRS, Institut de Génomique Fonctionnelle de Lyon, UMR 5242, F-69007 Lyon, France
| | - Anne Emilie Bouchardon
- Ecole Nationale Supérieure des Mines de Saint-Étienne (ENSM-SE), Centre SPIN-EVS, UMR5600, F-42023 Saint- Étienne tienne, France
| | - Anna Hua
- Université de Lyon, Université Jean Monnet Saint-Etienne, CNRS, EVS-ISTHME UMR 5600, F-42023 Saint-Étienne, France
| | - Frédéric Paran
- Ecole Nationale Supérieure des Mines de Saint-Étienne (ENSM-SE), Centre SPIN-EVS, UMR5600, F-42023 Saint- Étienne tienne, France
| | - Jean Luc Bouchardon
- Ecole Nationale Supérieure des Mines de Saint-Étienne (ENSM-SE), Centre SPIN-EVS, UMR5600, F-42023 Saint- Étienne tienne, France
| | - Olivier Faure
- Ecole Nationale Supérieure des Mines de Saint-Étienne (ENSM-SE), Centre SPIN-EVS, UMR5600, F-42023 Saint- Étienne tienne, France
| |
Collapse
|
9
|
Kirkok SK, Kibet JK, Kinyanjui TK, Okanga FI. A review of persistent organic pollutants: dioxins, furans, and their associated nitrogenated analogues. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-03551-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
|
10
|
Saibu S, Adebusoye SA, Oyetibo GO, Rodrigues DF. Aerobic degradation of dichlorinated dibenzo-p-dioxin and dichlorinated dibenzofuran by bacteria strains obtained from tropical contaminated soil. Biodegradation 2020; 31:123-137. [PMID: 32342243 DOI: 10.1007/s10532-020-09898-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 04/07/2020] [Indexed: 11/26/2022]
Abstract
Bacterial diversity and aerobic catabolic competence of dioxin-degrading bacterial strains isolated from a polluted soil in the tropics were explored. Isolation of bacteria occurred after 12 months of consecutive enrichment, with dioxin congeners serving as the only sources of carbon and energy. Seventeen strains that were isolated were subsequently screened for dioxin metabolic competence. Among these isolates, five had unique amplified ribosomal DNA restriction analysis (ARDRA) patterns out of which two exhibiting good metabolic competence were selected for further investigation. The two strains were identified as Bacillus sp. SS2 and Serratia sp. SSA1, based on their 16S rRNA gene sequences. Bacterial growth co-occurred with dioxin disappearance and near stoichiometric release of chloride for one ring of the chlorinated congeners. The overall percentage removal of dibenzofuran (DF) by strain SS2 was 93.87%; while corresponding values for 2,8-dichlorodibenzofuran (2,8-diCDF) and 2,7-dichlorodibenzo-p-dioxin (2,7-diCDD) were 86.22% and 82.30% respectively. In the case of strain SSA1, percentage removal for DF, 2,8-diCDF and 2,7-diCDD were respectively 98.9%, 80.97% and 70.80%. The presence of two dioxin dioxygenase catabolic genes (dxnA1 and dbfA1) was investigated. Only the dbfA1 gene could be amplified in SS2 strain. Results further revealed that strain SS2 presented higher expression levels for the alpha-subunit of DF dioxygenase (dbfA1) gene during growth with dioxins. The expression level for dbfA1 gene was higher when growing on DF than on the other chlorinated analogs. This study gives an insight into dioxin degradation, with the catabolic potential of strains SS2 and SSA1 (an enteric bacterium) within the sub-Sahara Africa. It further shows that dioxin catabolic potential might be more prevalent in different groups of microorganisms than previously believed. Few reports have demonstrated the degradation of chlorinated congeners of dioxins, particularly from sub-Saharan African contaminated systems.
Collapse
Affiliation(s)
- Salametu Saibu
- Department of Microbiology, Faculty of Science, University of Lagos, Akoka, Yaba, Lagos, Nigeria
- Department of Civil and Environmental Engineering, University of Houston, Houston, TX, 77204-4003, USA
| | - Sunday A Adebusoye
- Department of Microbiology, Faculty of Science, University of Lagos, Akoka, Yaba, Lagos, Nigeria.
| | - Ganiyu O Oyetibo
- Department of Microbiology, Faculty of Science, University of Lagos, Akoka, Yaba, Lagos, Nigeria
| | - Debora F Rodrigues
- Department of Civil and Environmental Engineering, University of Houston, Houston, TX, 77204-4003, USA
| |
Collapse
|
11
|
Saibu S, Adebusoye SA, Oyetibo GO. Aerobic bacterial transformation and biodegradation of dioxins: a review. BIORESOUR BIOPROCESS 2020. [DOI: 10.1186/s40643-020-0294-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractWaste generation tends to surge in quantum as the population and living conditions grow. A group of structurally related chemicals of dibenzofurans and dibenzo-p-dioxins including their chlorinated congeners collectively known as dioxins are among the most lethal environmental pollutants formed during different anthropogenic activities. Removal of dioxins from the environment is challenging due to their persistence, recalcitrance to biodegradation, and prevalent nature. Dioxin elimination through the biological approach is considered both economically and environmentally as a better substitute to physicochemical conventional approaches. Bacterial aerobic degradation of these compounds is through two major catabolic routes: lateral and angular dioxygenation pathways. Information on the diversity of bacteria with aerobic dioxin degradation capability has accumulated over the years and efforts have been made to harness this fundamental knowledge to cleanup dioxin-polluted soils. This paper covers the previous decades and recent developments on bacterial diversity and aerobic bacterial transformation, degradation, and bioremediation of dioxins in contaminated systems.
Collapse
|
12
|
Lopez-Echartea E, Strejcek M, Mateju V, Vosahlova S, Kyclt R, Demnerova K, Uhlik O. Bioremediation of chlorophenol-contaminated sawmill soil using pilot-scale bioreactors under consecutive anaerobic-aerobic conditions. CHEMOSPHERE 2019; 227:670-680. [PMID: 31022668 DOI: 10.1016/j.chemosphere.2019.04.036] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 02/07/2019] [Accepted: 04/05/2019] [Indexed: 06/09/2023]
Abstract
Chlorophenols (CPs), including pentachlorophenol (PCP), are chemicals of concern due to their toxicity and persistence. Here we describe a successful reactor-based remediation of CP-contaminated soil and assess changes in the toxicity patterns and bacterial communities during the remediation. The remediation consisted of separating half of the contaminated soil to be ground (samples M) in order to test whether the grinding expedited the remediation, the other half was left unground (samples P). Both soils were mixed with wastewater treatment sludge to increase their bacterial diversity and facilitate the degradation of CPs, and the resultant mixtures were placed in 2 bioreactors, M and P, operated for 16 months under anaerobic conditions to favor dehalogenation and for an additional 16 months under aerobic conditions to achieve complete mineralization. Samples were taken every 4 months for toxicity and microbial analyses. The results showed a 64% removal of total CPs (ΣCPs) in reactor P after just 18 months of remediation, whereas similar depletion in reactor M occurred after ∼25 months, indicating that the grinding decelerated the remediation. By the end of the experiment, both reactors achieved 93.5-95% removal. The toxicity tests showed a decrease in toxicity as the remediation progressed. The succession of bacterial communities over time was significantly associated with pH, anaerobic/aerobic phase and the concentration of the majority of CP congeners. Our data indicate that the supplementation of contaminated soil with sludge and further incubation in pilot-scale bioreactors under consecutive anaerobic-aerobic conditions proved to be effective at the remediation of CP-contaminated soil.
Collapse
Affiliation(s)
- Eglantina Lopez-Echartea
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Czech Republic
| | - Michal Strejcek
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Czech Republic
| | | | | | | | - Katerina Demnerova
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Czech Republic
| | - Ondrej Uhlik
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Czech Republic.
| |
Collapse
|
13
|
Wu JH, Chen WY, Kuo HC, Li YM. Redox fluctuations shape the soil microbiome in the hypoxic bioremediation of octachlorinated dibenzodioxin- and dibenzofuran-contaminated soil. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 248:506-515. [PMID: 30831347 DOI: 10.1016/j.envpol.2019.02.053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 02/16/2019] [Accepted: 02/17/2019] [Indexed: 06/09/2023]
Abstract
The biodegradation of polychlorinated-p-dioxins and dibenzofurans (PCDD/Fs) has been recently demonstrated in a single reactor under hypoxic conditions. Maintaining hypoxic conditions through periodic aerations results in a marked fluctuation of reduction-oxidation (redox) potential. To further assess the effects of redox fluctuations, we operated two fed-batch continuously stirred tank reactors (CSTRs) with sophisticated redox controls at different anoxic/oxic fluctuations to reduce PCDD/Fs in contaminated soil. The results of long-term reactor operation showed that the CSTR with redox fluctuations at a narrow range (-63 ± 68 mV) (CSTR_A) revealed a higher substrate hydrolysis level and PCDD/F degradation rate than did the CSTR with a redox potential that fluctuated at a broad range (-13 ± 118 mV) (CSTR_B). In accordance with analyses of bacterial 16S rRNA genes, the designated hypoxic conditions with added compost supported survival of bacterial populations at a density of approximately 109 copies/g slurry. The evolved core microbiome was dominated by anoxic/oxic fluctuation-adapted Bacteroidetes, Alphaproteobacteria, and Actinobacteria, with higher species diversity and functionality, including hydrolysis and degradation of dioxin-like compounds in CSTR_A than in CSTR_B. Taken together, the overall results of this study expand the understanding of redox fluctuations in association with the degradation of recalcitrant substrates in soil and the corresponding microbiome.
Collapse
Affiliation(s)
- Jer-Horng Wu
- Department of Environmental Engineering, National Cheng Kung University, Tainan City, Taiwan.
| | - Wei-Yu Chen
- Department of Environmental Engineering, National Cheng Kung University, Tainan City, Taiwan
| | - Hung-Chih Kuo
- Department of Environmental Engineering, National Cheng Kung University, Tainan City, Taiwan
| | - Yun-Ming Li
- Mass Laboratory, National Chiao-Tung University, Hsinchu, Taiwan
| |
Collapse
|
14
|
Huang WY, Ngo HH, Lin C, Vu CT, Kaewlaoyoong A, Boonsong T, Tran HT, Bui XT, Vo TDH, Chen JR. Aerobic co-composting degradation of highly PCDD/F-contaminated field soil. A study of bacterial community. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 660:595-602. [PMID: 30641388 DOI: 10.1016/j.scitotenv.2018.12.312] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/18/2018] [Accepted: 12/21/2018] [Indexed: 06/09/2023]
Abstract
This study investigated bacterial communities during aerobic food waste co-composting degradation of highly PCDD/F-contaminated field soil. The total initial toxic equivalent quantity (TEQ) of the soil was 16,004 ng-TEQ kg-1 dry weight. After 42-day composting and bioactivity-enhanced monitored natural attenuation (MNA), the final compost product's TEQ reduced to 1916 ng-TEQ kg-1 dry weight (approximately 75% degradation) with a degradation rate of 136.33 ng-TEQ kg-1 day-1. Variations in bacterial communities and PCDD/F degraders were identified by next-generation sequencing (NGS). Thermophilic conditions of the co-composting process resulted in fewer observed bacteria and PCDD/F concentrations. Numerous organic compound degraders were identified by NGS, supporting the conclusion that PCDD/Fs were degraded during food waste co-composting. Bacterial communities of the composting process were defined by four phyla (Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes). At the genus level, Bacillus (Firmicutes) emerged as the most dominant phylotype. Further studies on specific roles of these bacterial strains are needed, especially for the thermophiles which contributed to the high degradation rate of the co-co-composting treatment's first 14 days.
Collapse
Affiliation(s)
- Wen-Yen Huang
- Institute of Marine Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan
| | - Huu-Hao Ngo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Chitsan Lin
- Institute of Marine Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan.
| | - Chi-Thanh Vu
- Civil and Environmental Engineering Department, The University of Alabama in Huntsville, Huntsville, AL 35899, USA.
| | - Acharee Kaewlaoyoong
- Department of Safety, Health and Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 82445, Taiwan
| | - Totsaporn Boonsong
- Institute of Marine Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan
| | - Huu-Tuan Tran
- Institute of Marine Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan
| | - Xuan-Thanh Bui
- Faculty of Environment and Natural Resources, University of Technology, Vietnam National University-Ho Chi Minh City, Vietnam
| | - Thi-Dieu-Hien Vo
- Institute of Marine Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan
| | - Jenq-Renn Chen
- Department of Safety, Health and Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 82445, Taiwan
| |
Collapse
|
15
|
Zhang G, Huang X, Liao W, Kang S, Ren M, Hai J. Measurement of Dioxin Emissions from a Small-Scale Waste Incinerator in the Absence of Air Pollution Controls. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16071267. [PMID: 30970588 PMCID: PMC6479856 DOI: 10.3390/ijerph16071267] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 03/31/2019] [Accepted: 03/31/2019] [Indexed: 11/24/2022]
Abstract
Polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) emissions from basic small-scale waste incinerators (SWI) may cause health risks in nearby people and are thus subject to stringent regulations. The aim of this study was to evaluate PCDD/F emission and reduction of a basic SWI in the absence of air pollution controls (APCs). The results indicated that the stack gas and fly ash presented average PCDD/F levels and emission factors of 3.6 ng international toxic equivalent (I-TEQ)/Nm3 and 189.31µg I-TEQ/t and 6.89 ng I-TEQ/g and 137.85µg I-TEQ/t, respectively, much higher than those from large municipal solid waste incinerators (MSWI). PCDD/Fs congener fingerprints indicated that de novo synthesis played a dominant role in the low-temperature post-combustion zone and increased the presence of high-chlorine substituted congeners. On the basis of the emission factor 327.24 µg I-TEQ/t-waste, approximately 3000 g I-TEQ dioxins might be generated in total through basic SWIs and open burning. After refitting an SWI by adding activated carbon injection with a bag filter (ACI+BG), the PCDD/F emissions decreased to mean values of 0.042 ng I-TEQ/Nm3, far below the standard of 0.1 ng I-TEQ/Nm3, and the removal efficiency reached 99.13% in terms of I-TEQ. Therefore, it is entirely feasible to considerably reduce PCDD/F emissions by refitting basic SWI, which is positive for the future development of rural solid waste (RSW (RSW) disposal by SWI.
Collapse
Affiliation(s)
- Gang Zhang
- Engineering Research Center of None-food Biomass Efficient Pyrolysis and Utilization Technology of Guangdong Higher Education Institutes, Dongguan University of Technology, Dongguan 523808, China.
| | - Xiangxuan Huang
- Engineering Research Center of None-food Biomass Efficient Pyrolysis and Utilization Technology of Guangdong Higher Education Institutes, Dongguan University of Technology, Dongguan 523808, China.
| | - Wenbo Liao
- Engineering Research Center of None-food Biomass Efficient Pyrolysis and Utilization Technology of Guangdong Higher Education Institutes, Dongguan University of Technology, Dongguan 523808, China.
| | - Shimin Kang
- Engineering Research Center of None-food Biomass Efficient Pyrolysis and Utilization Technology of Guangdong Higher Education Institutes, Dongguan University of Technology, Dongguan 523808, China.
| | - Mingzhong Ren
- South China Institute of Environmental Sciences, Ministry of Ecological Environment, Guangzhou 510000, China.
| | - Jing Hai
- South China Institute of Environmental Sciences, Ministry of Ecological Environment, Guangzhou 510000, China.
| |
Collapse
|
16
|
Liu Q, Li Q, Wang N, Liu D, Zan L, Chang L, Gou X, Wang P. Bioremediation of petroleum-contaminated soil using aged refuse from landfills. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 77:576-585. [PMID: 29754988 DOI: 10.1016/j.wasman.2018.05.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 03/21/2018] [Accepted: 05/05/2018] [Indexed: 06/08/2023]
Abstract
This study explored the effects and mechanisms of petroleum-contaminated soil bioremediation using aged refuse (AR) from landfills. Three treatments of petroleum-contaminated soil (47.28 mg·g-1) amended with AR, sterilized aged refuse (SAR) and petroleum-contaminated soil only (as a control) were tested. During 98 days of incubation, changes in soil physicochemical properties, residual total petroleum hydrocarbon (TPH), biodegradation kinetics, enzyme activities and the microbial community were investigated. The results demonstrated that AR was an effective soil conditioner and biostimulation agent that could comprehensively improve the quality of petroleum-contaminated soil and promote microbial growth, with an 74.64% TPH removal rate, 22.36 day half-life for SAR treatment, compared with the control (half-life: 138.63 days; TPH removal rate: 22.40%). In addition, the petroleum-degrading bacteria isolation results demonstrated that AR was also a petroleum-degrading microbial agent containing abundant microorganisms. AR addition significantly improved both the biotic and abiotic conditions of petroleum-contaminated soil without other additives. The cooperation of conditioner addition, biostimulation and bioaugmentation in AR treatment led to better bioremediation effects (half-life: 13.86 days; TPH removal rate: 89.83%). In conclusion, AR amendment is a cost-effective, easy-to-use method facilitating in situ large-scale application while simultaneously recycling huge amounts of AR from landfills.
Collapse
Affiliation(s)
- Qingmei Liu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China.
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
| | - Ning Wang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
| | - Dan Liu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China.
| | - Li Zan
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
| | - Le Chang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
| | - Xuemei Gou
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
| | - Peijin Wang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
| |
Collapse
|
17
|
Microbiome Dynamics in a Shrimp Grow-out Pond with Possible Outbreak of Acute Hepatopancreatic Necrosis Disease. Sci Rep 2017; 7:9395. [PMID: 28839269 PMCID: PMC5571196 DOI: 10.1038/s41598-017-09923-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 08/01/2017] [Indexed: 11/08/2022] Open
Abstract
Acute hepatopancreatic necrosis disease (AHPND) (formerly, early mortality syndrome) is a high-mortality-rate shrimp disease prevalent in shrimp farming areas. Although AHPND is known to be caused by pathogenic Vibrio parahaemolyticus hosting the plasmid-related PirABvp toxin gene, the effects of disturbances in microbiome have not yet been studied. We took 62 samples from a grow-out pond during an AHPND developing period from Days 23 to 37 after stocking white postlarvae shrimp and sequenced the 16S rRNA genes with Illumina sequencing technology. The microbiomes of pond seawater and shrimp stomachs underwent varied dynamic succession during the period. Despite copies of PirABvp, principal co-ordinates analysis revealed two distinctive stages of change in stomach microbiomes associated with AHPND. AHPND markedly changed the bacterial diversity in the stomachs; it decreased the Shannon index by 53.6% within approximately 7 days, shifted the microbiome with Vibrio and Candidatus Bacilloplasma as predominant populations, and altered the species-to-species connectivity and complexity of the interaction network. The AHPND-causing Vibrio species were predicted to develop a co-occurrence pattern with several resident and transit members within Candidatus Bacilloplasma and Cyanobacteria. This study’s insights into microbiome dynamics during AHPND infection can be valuable for minimising this disease in shrimp farming ponds.
Collapse
|
18
|
Bacterial Biotransformation of Pentachlorophenol and Micropollutants Formed during Its Production Process. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:ijerph13111146. [PMID: 27869691 PMCID: PMC5129356 DOI: 10.3390/ijerph13111146] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 11/07/2016] [Accepted: 11/08/2016] [Indexed: 11/17/2022]
Abstract
Pentachlorophenol (PCP) is a toxic and persistent wood and cellulose preservative extensively used in the past decades. The production process of PCP generates polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) as micropollutants. PCDD/Fs are also known to be very persistent and dangerous for human health and ecosystem functioning. Several physico-chemical and biological technologies have been used to remove PCP and PCDD/Fs from the environment. Bacterial degradation appears to be a cost-effective way of removing these contaminants from soil while causing little impact on the environment. Several bacteria that cometabolize or use these pollutants as their sole source of carbon have been isolated and characterized. This review summarizes current knowledge on the metabolic pathways of bacterial degradation of PCP and PCDD/Fs. PCP can be successfully degraded aerobically or anaerobically by bacteria. Highly chlorinated PCDD/Fs are more likely to be reductively dechlorinated, while less chlorinated PCDD/Fs are more prone to aerobic degradation. The biochemical and genetic basis of these pollutants’ degradation is also described. There are several documented studies of effective applications of bioremediation techniques for the removal of PCP and PCDD/Fs from soil and sediments. These findings suggest that biodegradation can occur and be applied to treat these contaminants.
Collapse
|