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Simbanegavi TT, Makuvara Z, Marumure J, Alufasi R, Karidzagundi R, Chaukura N, Musvuugwa T, Okiobe ST, Rzymski P, Gwenzi W. Are earthworms the victim, facilitator or antidote of antibiotics and antibiotic resistance at the soil-animal-human interface? A One-Health perspective. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 945:173882. [PMID: 38866146 DOI: 10.1016/j.scitotenv.2024.173882] [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: 03/23/2024] [Revised: 06/04/2024] [Accepted: 06/07/2024] [Indexed: 06/14/2024]
Abstract
The transfer of antibiotics and antibiotic resistance (AR) to the soil systems poses ecological hazards to various organisms, including earthworms. Understanding the complex interactions between earthworms, antibiotics, and AR in the soil system requires a comprehensive assessment. Hence, the present review investigates the behaviour, fate, impacts, and mechanisms involved in the interaction of earthworms with antibiotics and AR. The antibiotics and AR detected in earthworms and their associated media, such as vermicompost, are presented, but several other antibiotics and AR widely detected in soils remain understudied. As receptors and bioassay organisms, earthworms are adversely affected by antibiotics and AR causing (1) acute and chronic toxicity, and (2) emergence of AR in previously susceptible earthworm gut microbiota, respectively. The paper also highlights that, apart from this toxicity, earthworms can also mitigate against antibiotics, antibiotic-resistant bacteria and antibiotic-resistance genes by reducing bacterial diversity and abundance. The behaviour and fate processes, including biodegradation pathways, biomarkers of antibiotics and AR in earthworms, are discussed. In addition, the factors controlling the behaviour and fate of antibiotics and AR and their interactions with earthworms are discussed. Overall, earthworms mitigate antibiotics and AR via various proximal and distal mechanisms, while dual but contradictory functions (i.e., mitigatory and facilitatory) were reported for AR. We recommend that future research based on the One-World-One-Health approach should address the following gaps: (1) under-studied antibiotics and AR, (2) degradation mechanisms and pathways of antibiotics, (3) effects of environmentally relevant mixtures of antibiotics, (4) bio-augmentation in earthworm-based bioremediation of antibiotics, (5) long-term fate of antibiotics and their metabolites, (6) bio-transfers of antibiotics and AR by earthworms, (7) development of earthworm biomarkers for antibiotics and AR, (8) application of earthworm-based bioremediation of antibiotics and AR, (9) cascading ecological impacts of antibiotics and AR on earthworms, and (10) pilot-scale field applications of earthworm-based bioremediation systems.
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Affiliation(s)
- Tinoziva T Simbanegavi
- Department of Soil Science and Environment, Faculty of Agriculture, Environment, and Food Systems, University of Zimbabwe, P. O. Box MP 167, Mount Pleasant, Harare, Zimbabwe
| | - Zakio Makuvara
- Department of Physics, Geography and Environmental Science, School of Natural Sciences, Great Zimbabwe University, Masvingo, Zimbabwe; Department of Life and Consumer Sciences, School of Agriculture and Life Sciences, College of Agriculture and Environmental Sciences, University of South Africa, South Africa
| | - Jerikias Marumure
- Department of Physics, Geography and Environmental Science, School of Natural Sciences, Great Zimbabwe University, Masvingo, Zimbabwe; Department of Life and Consumer Sciences, School of Agriculture and Life Sciences, College of Agriculture and Environmental Sciences, University of South Africa, South Africa
| | - Richwell Alufasi
- Biological Sciences Department, Bindura University of Science Education, 741 Chimurenga Road, Off Trojan Road, P. Bag 1020, Bindura, Zimbabwe
| | - Rangarirayi Karidzagundi
- Materials Development Unit, Zimbabwe Open University, P.O. Box MP1119, Mount Pleasant, Harare, Zimbabwe
| | - Nhamo Chaukura
- Department of Physical and Earth Sciences, Sol Plaatje University, Kimberley 8301, South Africa
| | - Tendai Musvuugwa
- Department of Physical and Earth Sciences, Sol Plaatje University, Kimberley 8301, South Africa
| | - Simon Thierry Okiobe
- Leibniz-Institut für Agrartechnik und Bioökonomie e.V. (ATB), Max-Eyth-Allee 100, D-14469 Potsdam, Germany
| | - Piotr Rzymski
- Department of Environmental Medicine, Poznan University of Medical Sciences, Poznań, Poland.
| | - Willis Gwenzi
- Formerly Alexander von Humboldt Fellow and Guest Professor, Leibniz-Institut für Agrartechnik und Bioökonomie e.V. (ATB), Max-Eyth-Allee 100, D-14469 Potsdam, Germany; Formerly Alexander von Humboldt Fellow and Guest Professor, Grassland Grassland Science and Renewable Plant Resources, Faculty of Organic Agricultural Sciences, Universität Kassel, Steinstraße 19, D-37213 Witzenhausen, Germany; Biosystems and Environmental Engineering Research Group, 380 New Adylin, Marlborough, Harare, Zimbabwe.
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Lei X, Cui G, Sun H, Hou S, Deng H, Li B, Yang Z, Xu Q, Huo X, Cai J. How do earthworms affect the pathway of sludge bio-stabilization via vermicomposting? THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170411. [PMID: 38280597 DOI: 10.1016/j.scitotenv.2024.170411] [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: 11/27/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 01/29/2024]
Abstract
The synergy effects between earthworms and microorganisms promote nitrogen mineralization and enhance stabilization of organic matters in a vermicomposting system. However, the stabilization pathways of vermicomposting in the system remain unknown. The aim of this study was to investigate the effect of earthworms on the stabilization pathway and associated microbial population of waste activated sludge recycled by vermicomposting. The treatment of sludge with and without earthworms was conducted at 20 °C for 60 days. The trends in organic matter (OM), dissolved organic carbon (DOC), NH4+-N, electrical conductivity (EC), microbial biomass carbon (MBC), and dehydrogenase activity (DHA) were similar in both systems over time. At the end of the treatment, OM and DOC were significantly lower (p < 0.05), and EC, NH4+-N, and NO3--N were significantly higher (p < 0.05) in the vermicomposting group than in the control. Based on the statistical results of principal component analysis (PCA), it was proposed that the stabilization pathway in both treatment systems required a sequence of reactions characterized by the degradation of organic matter, accumulation of dissolved organic carbon, ammonification, and nitrification. Vermicomposting led to greater abundance and diversity (Shannon index) of 16S rDNA microbial species, but more even distribution in microbial community composition (Simpson index) than the control. However, the opposite performance for 18S rDNA microbes was observed. Vermicomposting enhanced the abundance of microorganisms involved in organic matter degradation and nitrification, facilitating the conversion of organic matter and favoring the nitrification. In short, the pathway of sludge bio-stabilization is not altered regardless of the addition of earthworms or not, which enables us to better understand vermicomposting process of sludge.
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Affiliation(s)
- Xuyang Lei
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Guangyu Cui
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
| | - Hongxin Sun
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Suxia Hou
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Hongying Deng
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Bo Li
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Zhengzheng Yang
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Qiushi Xu
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Xueyu Huo
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Jiaxuan Cai
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
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Jiang H, Zhang L, Wang X, Gu J, Song Z, Wei S, Guo H, Xu L, Qian X. Reductions in abundances of intracellular and extracellular antibiotic resistance genes by SiO 2 nanoparticles during composting driven by mobile genetic elements. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 341:118071. [PMID: 37148762 DOI: 10.1016/j.jenvman.2023.118071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 04/24/2023] [Accepted: 04/28/2023] [Indexed: 05/08/2023]
Abstract
Applying exogenous additives during the aerobic composting of livestock manure is effective for slowing down the spread of antibiotic resistance genes (ARGs) in the environment. Nanomaterials have received much attention because only low amounts need to be added and they have a high capacity for adsorbing pollutants. Intracellular ARGs (i-ARGs) and extracellular ARGs (e-ARGs) comprise the resistome in livestock manure but the effects of nanomaterials on the fates of these different fractions during composting are still unclear. Thus, we investigated the effects of adding SiO2 nanoparticles (SiO2NPs) at four levels (0 (CK), 0.5 (L), 1 (M), and 2 g/kg (H)) on i-ARGs, e-ARGs, and the bacterial community during composting. The results showed that i-ARGs represented the main fraction of ARGs during aerobic composting of swine manure, and their abundance was lowest under M. Compared with CK, M increased the removal rates of i-ARGs and e-ARGs by 17.9% and 100%, respectively. SiO2NPs enhanced the competition between ARGs hosts and non-hosts. M optimized the bacterial community by reducing the abundances of co-hosts (Clostridium_sensu_stricto_1, Terrisporobacter, and Turicibacter) of i-ARGs and e-ARGs (by 96.0% and 99.3%, respectively) and killing 49.9% of antibiotic-resistant bacteria. Horizontal gene transfer dominated by mobile genetic elements (MGEs) played a key role in the changes in the abundances of ARGs. i-intI1 and e-Tn916/1545 were key MGEs related closely to ARGs, and the maximum decreases of 52.8% and 100%, respectively, occurred under M, which mainly explained the decreased abundances of i-ARGs and e-ARGs. Our findings provide new insights into the distribution and main drivers of i-ARGs and e-ARGs, as well as demonstrating the possibility of adding 1 g/kg SiO2NPs to reduce the propagation of ARGs.
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Affiliation(s)
- Haihong Jiang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China; School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, Guangdong, 510000, China
| | - Li Zhang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiaojuan Wang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China; Shaanxi Engineering Research Center of Utilization of Agricultural Waste Resources, Northwest A&F University, Yangling, Shaanxi, 712100, China.
| | - Jie Gu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China; Shaanxi Engineering Research Center of Utilization of Agricultural Waste Resources, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Zilin Song
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China; Shaanxi Engineering Research Center of Utilization of Agricultural Waste Resources, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Shumei Wei
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Honghong Guo
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Liang Xu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xun Qian
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China
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Hao X, Zhang W, Zhao L, Shen L, Zhu L, Zeng B, Jiang D, Bai L. Bacillus subtilis reduces antibiotic resistance genes of animal sludge in vermicomposting by improving heat stress tolerance of Eisenia foetida and bacterial community adjustment. ENVIRONMENTAL RESEARCH 2023; 219:115088. [PMID: 36529325 DOI: 10.1016/j.envres.2022.115088] [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: 10/12/2022] [Revised: 11/29/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
Antibiotic resistance genes (ARGs) in livestock industry have been recognized as a kind of pollutant. The effect of Bacillus subtilis (B. subtilis) as an additive for the reduction of ARGs in animal sludge from livestock and poultry wastewater treatment plant during vermicomposting was investigated. We also evaluated the oxidative stress level and growth of earthworms, Eisenia foetida, bacterial community succession, and the quality of the end products. Two treatments were conducted using B. subtilis, one at 18 °C and another at 28 °C. Controls were setup without the bacteria. The results showed that inoculation of B. subtilis promoted the degradation of organics at 28 °C and increased the germination index to 236%. The increased activities of the superoxide dismutase (1.69 U/mg pr) and catalase (8.05 U/mg pr) and the decreased activity of malondialdehyde (0.02 nmol/mg pr) by B. subtilis at 28 °C showed that the earthworms were relieved of heat stress. The addition of B. subtilis reduced the abundance of 32 target ARGs, including integron (intI-1), transposase (IS613) and resistant genes, such as sulfonamide (sul2), quinolone (oprJ), macrolide-lincosamide-streptogramin group B (ermF, ermB), tetracycline (tetL-02, tetX), β-lactama (blaOXA10-01) and aminoglycoside [strB, aac(6')-Ib(aka aacA4)-01, aac(6')-Ib(aka aacA4)-02]. Organic matter degrading Membranicola, Paludisphaera, Sphingorhabdus and uncultured bacterium belonging to the order Chitinophagales, nitrifying and nitrogen-fixing Singulisphaera and Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, soil remediating Achromobacter, and plant growth promoting Kaistia, Galbibacter and Ilumatobacter were increased significantly (P < 0.05). However, the growth of harmful bacteria such as Burkholderiaceae was inhibited in the vermicompost. In earthworm guts, the probiotic Mesorhizobium was promoted, while the pathogenic uncultured bacterium belonging to the family Enterobacteriaceae was reduced. Besides, B. subtilis enhanced the host relationships between bacteria and ARGs. These findings might be helpful in the removal of ARGs in animal wastes and in understanding the synergy between earthworms and microorganisms.
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Affiliation(s)
- Xiaoxia Hao
- Lab of Animal Ecology and Environmental Control, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, PR China
| | - Wenjin Zhang
- Lab of Animal Ecology and Environmental Control, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, PR China
| | - Liangbin Zhao
- Lab of Animal Ecology and Environmental Control, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, PR China
| | - Linyuan Shen
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, PR China
| | - Li Zhu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, PR China
| | - Bo Zeng
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, PR China
| | - Dongmei Jiang
- Lab of Animal Ecology and Environmental Control, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, PR China
| | - Lin Bai
- Lab of Animal Ecology and Environmental Control, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, PR China.
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Wang Y, Sutton NB, Zheng Y, Dong H, Rijnaarts HHM. Seasonal variation in antibiotic resistance genes and bacterial phenotypes in swine wastewater during three-chamber anaerobic pond treatment. ENVIRONMENTAL RESEARCH 2023; 216:114495. [PMID: 36208778 DOI: 10.1016/j.envres.2022.114495] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/23/2022] [Accepted: 10/01/2022] [Indexed: 06/16/2023]
Abstract
Antibiotic resistance is a global public health concern. Antibiotic usage in pigs makes swine wastewater (SW) a reservoir for antibiotic resistance genes (ARGs). SW is usually stored and treated in a three-chamber anaerobic pond (3-CAP) in medium and small pig farms in northern China. However, the yet unexplored presence of ARGs in SW during 3-CAP treatment may result in ARGs spreading into the environment if farmers apply SW to farmland as a liquid organic fertilizer. This study investigated the profiles of and changes in ARGs in SW during its treatment in 3-CAP over four seasons and analyzed the correlation between ARGs and bacterial phenotypes, along with the physicochemical parameters of the water. The results revealed that ARG abundance decreased considerably after 3-CAP treatment in April (47%), October (47%), and December (62%) but increased in May (43%) and August (73%). The ARG copies in the influent and other SW samples increased significantly from 107 copies/mL in April to 109 copies/mL in October and were maintained in December. The increase in ARG abundance was not as rapid as the growth of the bacterial population, resulting in lower relative abundance in October and December. Bacterial communities possessed more sul1 and tetM genes, which were also positively correlated with mobile genetic elements. After the 3-CAP treatment, 16% of antibiotics and 60% of heavy metals were removed, and both had a weak correlation with ARGs. Predicted phenotypes showed that gram-positive (G+) and gram-negative (G-) bacteria have different capacities for carrying ARGs. G+ bacteria carry more ARGs than G- bacteria. This study revealed the persistence of ARGs in SW after 3-CAP treatment over different seasons. Applying SW in the proper month will mitigate ARG dissemination to the environment.
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Affiliation(s)
- Yi Wang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China; Key Laboratory of Energy Conservation and Waste Management of Agricultural Structures, Ministry of Agriculture and Rural Affairs, Beijing, 100081, China; Department of Environmental Technology, Wageningen University and Research, P.O.Box 17, 6700, AA Wageningen, the Netherlands
| | - Nora B Sutton
- Department of Environmental Technology, Wageningen University and Research, P.O.Box 17, 6700, AA Wageningen, the Netherlands
| | - Yunhao Zheng
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China; Key Laboratory of Energy Conservation and Waste Management of Agricultural Structures, Ministry of Agriculture and Rural Affairs, Beijing, 100081, China
| | - Hongmin Dong
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China; Key Laboratory of Energy Conservation and Waste Management of Agricultural Structures, Ministry of Agriculture and Rural Affairs, Beijing, 100081, China.
| | - Huub H M Rijnaarts
- Department of Environmental Technology, Wageningen University and Research, P.O.Box 17, 6700, AA Wageningen, the Netherlands
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Rumky J, Kruglova A, Repo E. Fate of antibiotic resistance genes (ARGs) in wastewater treatment plant: Preliminary study on identification before and after ultrasonication. ENVIRONMENTAL RESEARCH 2022; 215:114281. [PMID: 36096165 DOI: 10.1016/j.envres.2022.114281] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/16/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
This study collected sludge samples from four different sections of a local wastewater treatment plant in Mikkeli, Finland, for antibiotic resistance genes (ARGs) analysis. Here, we examine the seven representative ARGs in sludge, encoding erythromycin (ermB), tetracycline (tetA, tetC, tetQ, tetW) and sulphonamide (sul1) to check abundance before and after ultrasonication. The class 1 integron (intl1) was also observed as an indicator of antibiotic resistance and horizontal gene transmission. The pre-treatment condition included 10 min of ultrasonication (US) for the sludge sample before freeze-drying. The droplet digital PCR system was used to assess the ARGs from the samples, and it was found that ARGs were not effectively eliminated by pre-treatment. After ultrasonication, tetA, tetC and tetQ did not show any variation but tetW showed 20 copies/ng of lower abundance in digested sludge than raw sludge, and a similar abundance was found in dewatered sludge. For MBR sludge, only ermB showed 1000 copies/ng higher abundance compared to the raw sample and surprisingly it did not show the presence of any other types of ARG. This study provides an overview of the appearance of ARGs in regional municipal sludge for further research reflection.
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Affiliation(s)
- Jannatul Rumky
- Department of Separation Science, LUT University, Sammonkatu 12, FI-50130, Mikkeli, Finland.
| | - Antonina Kruglova
- Department of Built Environment, Aalto University, Tietotie 1E, 15200, Espoo, Finland
| | - Eveliina Repo
- Department of Separation Science, LUT University, Sammonkatu 12, FI-50130, Mikkeli, Finland
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Cui G, Lü F, Hu T, Zhang H, Shao L, He P. Vermicomposting leads to more abundant microplastics in the municipal excess sludge. CHEMOSPHERE 2022; 307:136042. [PMID: 35981618 DOI: 10.1016/j.chemosphere.2022.136042] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 06/12/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Municipal excess activated sludge is not only an important reservoir of microplastics particles, but is also a vehicle of entry of microplastics into the environments as soil amendments or organic fertilizer. Vermicomposting is a cost-effective technology for sludge valorization. However, it is not clear whether vermicomposting affects the occurrence of microplastics in residual sludge. Here, the variation of microplastics (0.05-5 mm) in sludge, including the abundance, type, size, and morphology, before and after vermicomposting by epigeic earthworms under different temperature conditions (15 °C, 20 °C and 25 °C) were investigated by micro Fourier Transform Infrared Spectroscopy (μ-FTIR) and Scanning Electronic Microscopy (SEM). More abundant (over 104 particles ∙kg-1 (dry weight)), and smaller microplastics (over 60% in total with 0.05-0.5 mm) in the treated sludge via earthworms were observed compared to the raw sludge. The increment of vermicomposting temperature was more obvious (p < 0.05) for the enrichment of the microplastics, especially for polyethylene particle. Gizzard grinding and microbial digestion in the gut of earthworms may contribute to the fragment of microplastics. The present study suggests that the sludge-sourced vermicompost is still an important hotspot of microplastics, posing a potential threat to the receiving environments.
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Affiliation(s)
- Guangyu Cui
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China; Shanghai Engineering Research Center of Multi-source Solid Wastes Co-processing and Energy Utilization, Shanghai, 200092, China.
| | - Fan Lü
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China; Shanghai Engineering Research Center of Multi-source Solid Wastes Co-processing and Energy Utilization, Shanghai, 200092, China
| | - Tian Hu
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China
| | - Hua Zhang
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China; Shanghai Engineering Research Center of Multi-source Solid Wastes Co-processing and Energy Utilization, Shanghai, 200092, China
| | - Liming Shao
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China; Shanghai Engineering Research Center of Multi-source Solid Wastes Co-processing and Energy Utilization, Shanghai, 200092, China
| | - Pinjing He
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China; Shanghai Engineering Research Center of Multi-source Solid Wastes Co-processing and Energy Utilization, Shanghai, 200092, China.
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