1
|
Song N, Zhuang J, Zhang H, Qian M, Wu H, Sun N. Stereoselective bioaccumulation and degradation of chiral pesticide hexythiazox in earthworm-soil microcosm. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 273:116148. [PMID: 38422791 DOI: 10.1016/j.ecoenv.2024.116148] [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: 12/31/2023] [Revised: 02/19/2024] [Accepted: 02/22/2024] [Indexed: 03/02/2024]
Abstract
The chiral pesticide hexythiazox was extensively employed in agricultural activities and has garnered growing concern for its harmful impact on the ecosystem. This study investigates the toxicodynamic earthworm at the enantiomeric level of hexythiazox. Earthworms exhibited notable enantioselectivity during the accumulation stage. Furthermore, the presence of earthworms can impact the rate of degradation and enantioselectivity of hexythiazox in soil. The accumulation of the two hexythiazox enantiomers in the earthworm adhered to the one-compartment model, whereas the elimination phase was governed by the first-order kinetics equation. Furthermore, it was discovered that there was no notable enantioselectivity observed during the elimination phase.
Collapse
Affiliation(s)
- Ningying Song
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, China; College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015, China
| | - Jiyang Zhuang
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, China; College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015, China
| | - Hu Zhang
- Zhejiang Province Key Laboratory for Food Safety, Institute of Agro-Product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Mingrong Qian
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou 310032, China
| | - Huizhen Wu
- College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015, China.
| | - Nabo Sun
- College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015, China.
| |
Collapse
|
2
|
Tong Z, Shen Y, Meng D, Yi X, Sun M, Dong X, Chu Y, Duan J. Ecological threat caused by malathion and its chiral metabolite in a honey bee-rape system: Stereoselective exposure risk and the mechanism revealed by proteome. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 874:162585. [PMID: 36870510 DOI: 10.1016/j.scitotenv.2023.162585] [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: 01/04/2023] [Revised: 02/27/2023] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
Honey bees play an important role in the ecological environment. Regrettably, a decline in honey bee colonies caused by chemical insecticides has occurred throughout the world. Potential stereoselective toxicity of chiral insecticides may be a hidden source of danger to bee colonies. In this study, the stereoselective exposure risk and mechanism of malathion and its chiral metabolite malaoxon were investigated. The absolute configurations were identified using an electron circular dichroism (ECD) model. Ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for chiral separation. In pollen, the initial residues of malathion and malaoxon enantiomers were 3571-3619 and 397-402 μg/kg, respectively, and R-malathion degraded relatively slowly. The oral LD50 values of R-malathion and S-malathion were 0.187 and 0.912 μg/bee with 5 times difference, respectively, and the malaoxon values were 0.633 and 0.766 μg/bee. The Pollen Hazard Quotient (PHQ) was used to evaluate exposure risk. R-malathion showed a higher risk. An analysis of the proteome, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and subcellular localization, indicated that energy metabolism and neurotransmitter transport were the main affected pathways. Our results provide a new scheme for the evaluation of the stereoselective exposure risk of chiral pesticides to honey bees.
Collapse
Affiliation(s)
- Zhou Tong
- Institute of Plant Protection and Agro-Product Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China; Key Laboratory of Agro-Product Safety Risk Evaluation (Hefei), Ministry of Agriculture, Hefei 230031, China
| | - Yan Shen
- Institute of Plant Protection and Agro-Product Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - DanDan Meng
- Institute of Plant Protection and Agro-Product Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China; Key Laboratory of Agro-Product Safety Risk Evaluation (Hefei), Ministry of Agriculture, Hefei 230031, China
| | - XiaoTong Yi
- Institute of Plant Protection and Agro-Product Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China; Key Laboratory of Agro-Product Safety Risk Evaluation (Hefei), Ministry of Agriculture, Hefei 230031, China
| | - MingNa Sun
- Institute of Plant Protection and Agro-Product Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China; Key Laboratory of Agro-Product Safety Risk Evaluation (Hefei), Ministry of Agriculture, Hefei 230031, China
| | - Xu Dong
- Institute of Plant Protection and Agro-Product Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China; Key Laboratory of Agro-Product Safety Risk Evaluation (Hefei), Ministry of Agriculture, Hefei 230031, China; Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Yue Chu
- Institute of Plant Protection and Agro-Product Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China; Key Laboratory of Agro-Product Safety Risk Evaluation (Hefei), Ministry of Agriculture, Hefei 230031, China
| | - JinSheng Duan
- Institute of Plant Protection and Agro-Product Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China; Key Laboratory of Agro-Product Safety Risk Evaluation (Hefei), Ministry of Agriculture, Hefei 230031, China.
| |
Collapse
|
3
|
Wang JQ, He ZC, Peng W, Han TH, Mei Q, Wang QZ, Ding F. Dissecting the Enantioselective Neurotoxicity of Isocarbophos: Chiral Insight from Cellular, Molecular, and Computational Investigations. Chem Res Toxicol 2023; 36:535-551. [PMID: 36799861 DOI: 10.1021/acs.chemrestox.2c00418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Chiral organophosphorus pollutants are found abundantly in the environment, but the neurotoxicity risks of these asymmetric chemicals to human health have not been fully assessed. Using cellular, molecular, and computational toxicology methods, this story is to explore the static and dynamic toxic actions and its stereoselective differences of chiral isocarbophos toward SH-SY5Y nerve cells mediated by acetylcholinesterase (AChE) and further dissect the microscopic basis of enantioselective neurotoxicity. Cell-based assays indicate that chiral isocarbophos exhibits strong enantioselectivity in the inhibition of the survival rates of SH-SY5Y cells and the intracellular AChE activity, and the cytotoxicity of (S)-isocarbophos is significantly greater than that of (R)-isocarbophos. The inhibitory effects of isocarbophos enantiomers on the intracellular AChE activity are dose-dependent, and the half-maximal inhibitory concentrations (IC50) of (R)-/(S)-isocarbophos are 6.179/1.753 μM, respectively. Molecular experiments explain the results of cellular assays, namely, the stereoselective toxic actions of isocarbophos enantiomers on SH-SY5Y cells are stemmed from the differences in bioaffinities between isocarbophos enantiomers and neuronal AChE. In the meantime, the modes of neurotoxic actions display that the key amino acid residues formed strong noncovalent interactions are obviously different, which are related closely to the molecular structural rigidity of chiral isocarbophos and the conformational dynamics and flexibility of the substrate binding domain in neuronal AChE. Still, we observed that the stable "sandwich-type π-π stacking" fashioned between isocarbophos enantiomers and aromatic Trp-86 and Tyr-337 residues is crucial, which notably reduces the van der Waals' contribution (ΔGvdW) in the AChE-(S)-isocarbophos complexes and induces the disparities in free energies during the enantioselective neurotoxic conjugations and thus elucidating that (S)-isocarbophos mediated by synaptic AChE has a strong toxic effect on SH-SY5Y neuronal cells. Clearly, this effort can provide experimental insights for evaluating the neurotoxicity risks of human exposure to chiral organophosphates from macroscopic to microscopic levels.
Collapse
Affiliation(s)
- Jia-Qi Wang
- School of Water and Environment, Chang'an University, Xi'an 710054, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an 710054, China
| | - Zhi-Cong He
- School of Water and Environment, Chang'an University, Xi'an 710054, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an 710054, China
| | - Wei Peng
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Tian-Hao Han
- School of Water and Environment, Chang'an University, Xi'an 710054, China
- School of Environment, Nanjing University, Nanjing 210023, China
| | - Qiong Mei
- School of Water and Environment, Chang'an University, Xi'an 710054, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an 710054, China
- School of Land Engineering, Chang'an University, Xi'an 710054, China
| | - Qi-Zhao Wang
- School of Water and Environment, Chang'an University, Xi'an 710054, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an 710054, China
| | - Fei Ding
- School of Water and Environment, Chang'an University, Xi'an 710054, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an 710054, China
| |
Collapse
|
4
|
Liu S, Wu Q, Zhong Y, He Z, Wang Z, Li R, Wang M. Fosthiazate exposure induces oxidative stress, nerve damage, and reproductive disorders in nontarget nematodes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:12522-12531. [PMID: 36112285 DOI: 10.1007/s11356-022-23010-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 09/09/2022] [Indexed: 06/15/2023]
Abstract
As a forceful nematicide, fosthiazate has been largely applied in the management of root-knot nematodes and other herbivorous nematodes. However, the toxicity of fosthiazate to nontarget nematodes is unclear. To explore the toxicity and the mechanisms of fosthiazate in nontarget nematodes, Caenorhabditis elegans was exposed to 0.01-10 mg/L fosthiazate. The results implied that treatment with fosthiazate at doses above 0.01 mg/L could cause injury to the growth, locomotion behavior, and reproduction of the nematodes. Moreover, L1 larvae were more vulnerable to fosthiazate exposure than L4 larvae. Reactive oxygen species (ROS) production and lipofuscin accumulation were fairly increased in 1 mg/L fosthiazate-exposed nematodes. Treatment with 0.1 mg/L fosthiazate significantly inhibited the activity of acetylcholinesterase (p < 0.01). Furthermore, subacute exposure to 10 mg/L fosthiazate strongly influenced the expression of genes related to oxidative stress, reproduction, and nerve function (e.g., gst-1, sod-1, puf-8, wee-1.3, and ace-1 genes). These findings suggested that oxidative stress, reproduction and nerve disorders could serve as key endpoints of toxicity induced by fosthiazate. The cyp-35a family gene was the main metabolic fosthiazate in C. elegans, and the cyp-35a5 subtype was the most sensitive, with a change in expression level of 2.11-fold compared with the control. These results indicate that oxidative stress and neurological and reproductive disorders played fundamental roles in the toxicity of fosthiazate in C. elegans and may affect the abundance and function of soil nematodes.
Collapse
Affiliation(s)
- Shiling Liu
- Department of Pesticide Science, College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing, 210095, Jiangsu province, China
| | - Qiqi Wu
- Department of Pesticide Science, College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing, 210095, Jiangsu province, China
| | - Yanru Zhong
- Department of Pesticide Science, College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing, 210095, Jiangsu province, China
| | - Zongzhe He
- Department of Pesticide Science, College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing, 210095, Jiangsu province, China
| | - Zhen Wang
- Department of Pesticide Science, College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing, 210095, Jiangsu province, China
| | - Rui Li
- Department of Pesticide Science, College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing, 210095, Jiangsu province, China
| | - Minghua Wang
- Department of Pesticide Science, College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing, 210095, Jiangsu province, China.
| |
Collapse
|
5
|
Li L, Shi H, Hua X, Wang M, Wang H. Intrinsic Clearance and Metabolism Pathway of Fosthiazate in Rat and Cock Liver Microsomes: From Chiral Assessment View. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:12654-12660. [PMID: 34695356 DOI: 10.1021/acs.jafc.1c05217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Chiral fosthiazate enters the organisms via environmental exposure and food web enrichment. Liver subcellular fractions of rats (RLM) and cocks (CLM) were prepared to explore the stereoselective metabolism of fosthiazate in vitro. The results indicated that fosthiazate exhibited different stereoselective metabolism behaviors in RLM and CLM. The clearance rate order of RLM to four fosthiazate stereoisomers was (1R,3R)-fosthiazate > (1S,3R)-fosthiazate > (1R,3S)-fosthiazate > (1S,3S)-fosthiazate. However, CLM showed a faster clearance rate to (1S,3S)-fosthiazate and (1S,3R)-fosthiazate than the other two stereoisomers. The molecular docking results revealed that the stereoselectivity was partially due to the stereospecific binding between fosthiazate stereoisomers and cytochrome P450 proteins. The main metabolism pathways of fosthiazate in RLM and CLM were oxidation and hydrolysis with five common metabolites including M299, M243, M227, M103, and M197 being identified by LC-TOF-MS/MS. The present study provides the accurate data on risk assessment of chiral fosthiazate.
Collapse
Affiliation(s)
- Lianshan Li
- College of Eco-Environment, Hebei University, Hebei Key Laboratory of Close-to-Nature Restoration Technology of Wetlands, Baoding 071002, China
| | - Haiyan Shi
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China
| | - Xiude Hua
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China
| | - Minghua Wang
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China
| | - Hongjie Wang
- College of Eco-Environment, Hebei University, Hebei Key Laboratory of Close-to-Nature Restoration Technology of Wetlands, Baoding 071002, China
| |
Collapse
|
6
|
Wang F, Gao J, Zhai W, Cui J, Hua Y, Zhou Z, Liu D, Wang P, Zhang H. Accumulation, distribution and removal of triazine pesticides by Eichhornia crassipes in water-sediment microcosm. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 219:112236. [PMID: 33989919 DOI: 10.1016/j.ecoenv.2021.112236] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/01/2021] [Accepted: 04/06/2021] [Indexed: 06/12/2023]
Abstract
After application, pesticides remained in the field may contaminate water resources through surface runoff and leaching, posing a threat to aquatic ecosystem. In the current study, the accumulation, translocation, distribution and removal of four triazine pesticides (simazine, atrazine, terbuthylazine and metribuzin) by free floating aquatic plant Eichhornia crassipes (E. crassipes) in water-sediment microcosm were investigated and the removal mechanisms were explored. E. crassipes was exposed to an initial concentration of 50 μg·L-1 and the pesticide levels in water, sediment, roots and shoots of E. crassipes were monitored during 30 days. The results demonstrated that E. crassipes was capable of accumulating triazine pesticides with the bio-concentration factor (BCF) ranging from 0.8 to 18.4. Triazine pesticides were mainly stored in roots, and root accumulation and translocation amount depend on the hydrophobicity of the pesticides. The removal of the pesticides in water were significantly accelerated by the presence of E. crassipes, with the removal efficiency ranging from 66% to 79% after 30 days of treatment. Though phytoaccumulation only constituted 2-18% of the total spiked pesticides in the microcosm, E. crassipes played a vital role in removing simazine, atrazine and metribuzin. However, microbial degradation in sediment was the main pathway for the removal of terbuthylazine in the microcosm. This study demonstrated the potential application of E. crassipes to accelerate removal of contaminants from aquatic environment.
Collapse
Affiliation(s)
- Fang Wang
- School of Ecology and Environment, Beijing Technology and Business University, Beijing 100048, China
| | - Jing Gao
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Pesticide, China Agricultural University, Beijing 100193, China
| | - Wangjing Zhai
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Pesticide, China Agricultural University, Beijing 100193, China
| | - Jingna Cui
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Pesticide, China Agricultural University, Beijing 100193, China
| | - Yifan Hua
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Pesticide, China Agricultural University, Beijing 100193, China
| | - Zhiqiang Zhou
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Pesticide, China Agricultural University, Beijing 100193, China
| | - Donghui Liu
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Pesticide, China Agricultural University, Beijing 100193, China
| | - Peng Wang
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Pesticide, China Agricultural University, Beijing 100193, China.
| | - Hongjun Zhang
- Institute for the Control of Agrochemicals, Ministry of Agriculture and Rural Affairs (ICAMA), No. 22 Maizidian Street, Chaoyang, Beijing 100125, China.
| |
Collapse
|
7
|
Level of pesticides contamination in the major river systems: A review on South Asian countries perspective. Heliyon 2021; 7:e07270. [PMID: 34189313 PMCID: PMC8220188 DOI: 10.1016/j.heliyon.2021.e07270] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/28/2021] [Accepted: 06/07/2021] [Indexed: 11/23/2022] Open
Abstract
Pesticides are chemical compounds used worldwide for different purposes. These chemicals are well known for their long life, high toxicity, and slow degradation process. Many developed countries including South Asian countries banned the use of pesticides for their adverse effects. However, several pesticides are found incessantly in water and soil. To highlight the recent situation of pesticide contamination in South Asian river systems, we have studied 136 relevant articles published from 2015 to 2020. Articles were gathered using several commonly available search engines and organized according to information related to river systems of South Asian countries. After thoroughly examining those research articles, we summarized that most of the river systems are contaminated by pesticides, where DDTs, HCHs, endosulfan, heptachlor, and chlorpyrifos are the key recognized compounds among them. Comparing the level of pesticides with standard guidelines, we found that the Tapi River and Chilika Lake of India are considerably more contaminated than other river basins. Multivariate analyses identified the industrial discharge and agricultural run-off of chemicals as the probable sources of pesticides in these rivers. By analyzing the amount of annual pesticide production, their use, and accordingly their considerable presence in the water systems of the South Asian countries, it is evident that the banned pesticides are used regularly by these countries and thus contaminating the environment. Therefore, the formulations of appropriate rules and their enforcement to control the manufacture and solicitation of such pesticides are an urgent need to save the environment.
Collapse
|
8
|
Fan Z, Liang Z, Luo A, Wang Y, Ma Y, Zhao Y, Lou X, Jia R, Zhang Y, Ping S. Effect on simultaneous removal of ammonia, nitrate, and phosphorus via advanced stacked assembly biological filter for rural domestic sewage treatment. Biodegradation 2021; 32:403-418. [PMID: 33877511 DOI: 10.1007/s10532-021-09928-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 01/13/2021] [Indexed: 11/24/2022]
Abstract
The discharge of ammonia-nitrogen (NH3-N), total nitrogen (TN), chemical oxygen demand (COD), and total phosphorus (TP) in rural sewage usually exceeds the Pollutant Discharge Standard for Urban Sewage Treatment Plants (GB18918-2002). Efficient and cost-effective removal of these pollutants cannot be simultaneously realized using conventional rural sewage treatment methods. Thus, an assembled biological filter (D50 × W50 × H113 cm), including a phosphorus removal layer filled with solid polymeric ferric sulfate and alternating aerobic-anaerobic layers, is proposed herein. The aerobic (anerobic) layers were filled with zeolite (zeolite and composite soil) at different intervals. This system was used for the treatment of synthetic sewage having COD: 122.0-227.0 mg/L; NH3-N: 29.1-47.0 mg/L; TN: 28.0-58.0 mg/L; and TP: 2.0-3.8 mg/L. Based on optimal operation conditions (40 L/h reflow rate, without artificial aeration, and 12-h operation cycle), the system showed NH3-N, TN, COD, and TP removal efficiencies of 87.1 ± 8.1, 83.4 ± 7.9, 91.0 ± 9.4, and 80.0 ± 6.4%, respectively. Further, in the pilot-scale test, under the same optimal parameters, the removal efficiencies of NH3-N, TN, COD, and TP were 78.9 ± 8.1, 75.4 ± 7.9, 82 ± 9.4, and 76 ± 6.4%, respectively. Furthermore, in the different functional units of the system, a large number of functional bacteria capable of efficiently facilitating the simultaneous removal of the different pollutants from sewage were identified. Therefore, this proposed system, which complies with current environmental discharge regulations, can be a more sustainable approach for the treatment of unattended rural sewage.
Collapse
Affiliation(s)
- Ziyun Fan
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Zhiwei Liang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China.
| | - Ancheng Luo
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Yunlong Wang
- Environmental Resources and Soil Fertilizer Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Yuanyuan Ma
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Yi Zhao
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Xiansheng Lou
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Ruijie Jia
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Yan Zhang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Shaowei Ping
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| |
Collapse
|