SCIENCE OF THE TOTAL ENVIRONMENT
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2024
·
IF 8.2
Yixing Zhang,Xueran Lin,Tang Xia,Hang Chen,Fu Huang,Chaohai Wei,Guanglei Qiu
The increased use of disinfection since the pandemic has led to increased effective chlorine concentration in municipal wastewater. Whereas, the specific impacts of active chlorine on nitrogen and phosphorus removal, the mediating communities, and the related metabolic activities in wastewater treatment plants (WWTPs) lack systematic investigation. We systematically analyzed the influences of chlorine disinfection on nitrogen and phosphorus removal activities using activated sludge from five full-scale WWTPs. Results showed that at an active chlorine concentration of 1.0 mg/g-SS, the nitrogen and phosphorus removal systems were not significantly affected. Major effects were observed at 5.0 mg/g-SS, where the nitrogen and phosphorus removal efficiency decreased by 38.9 % and 44.1 %, respectively. At an active chlorine concentration of 10.0 mg/g-SS, the nitrification, denitrification, phosphorus release and uptake activities decreased by 15.1 %, 69.5–95.9 %, 49.6 % and 100 %, respectively. The proportion of dead cells increased by 6.1 folds. Reverse transcriptional quantitative polymerase chain reaction (RT-qPCR) analysis showed remarkable inhibitions on transcriptions of the nitrite oxidoreductase gene ( nxr B), the nitrite reductase genes ( nir S and nir K), and the nitrite reductase genes ( nar G). The nitrogen and phosphorus removal activities completely disappeared with an active chlorine concentration of 25.0 mg/g-SS. Results also showed distinct sensitivities of different functional bacteria in the activated sludge. Even different species within the same functional group differ in their susceptibility. This study provides a reference for the understanding of the threshold active chlorine concentration values which may potentially affect biological nitrogen and phosphorus removal in full-scale WWTPs, which are expected to be beneficial for decision-making in WWTPs to counteract the potential impacts of increased active chlorine concentrations in the influent wastewater.
研究领域:
环境工程
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污水处理
·
微生物学
·
生物技术
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2024
·
IF 7.7
Chang-An Huan,Qiandi Wang,Xiqi Li,Cong Du,Qingjie Meng,Xu Kang,Wenzong Liu
A huge production of waste activated sludge (WAS) has been a burden for wastewater treatment plants (WWTPs) with high disposal cost and little benefit back to wastewater purification. The short-chain fatty acids (SCFAs) produced by a short-term acidogenic fermentation of WAS before methane production have been proven to be a high-quality carbon source available for microbial denitrification process. The dual purpose of full recovery of fermentation liquid products and facilitating disposal of residual solid waste necessitate an efficient solid-liquid separation process of short-term fermentation liquid. The transformation and loss of various soluble carbon sources between solid and liquid are very important issues for carbon recovery efficiency when combining short-term fermentation and sludge dewatering in WWTPs. Here we testified the three conventional preconditioning coagulants, Polyferric Sulfate (PFS), Poly Aluminum Chloride (PAC) and Polyacrylamide (PAM), to improve the efficiency of subsequent solid-liquid separation. The results show that conversion yield of SCFAs in the liquid phase of sludge after short-term fermentation was 195 mg COD/g VSS, when using the coagulants PFS, PAC, and PAM for recovery, the recovery ratio was 79.5%, 82.0%, and 85.9%, respectively, while the dewaterability could be improved after preconditioning short-term fermentation sludge. The complexation of Al 3+ /Fe 3+ in metal coagulants with carboxyl groups of SCFA demonstrated by Density Functional Theory calculation led to small part of soluble carbons co-migration to the solid phase, mainly a loss of high molecular weight organic compounds (carbohydrate, proteins, humic acids), while the application of PAM had little impact on carbon recovery. Economic calculations further showed PAM preconditioning short-term fermentation liquid of WAS could achieve higher recovery benefits.
研究领域:
环境工程
·
污水处理
·
生物技术
✓ 已验证
DOI
高影响因子
Microbiome
·
2025
·
IF 12.7
Chao-Fan Yin,Piaopiao Pan,Tao Li,Xin Song,Ying Xu,Ning-Yi Zhou
Background Acetaminophen, a widely used analgesic and antipyretic drug, has become a significant aquatic micro-pollutant due to its extensive global production and increased consumption, particularly during the COVID-19 pandemic. Its high-water solubility leads to its pervasive presence in wastewater treatment plants (WWTPs), posing substantial risks to the environment and human health. Biological treatment is one of the promising approaches to remove such pollutants. Although previous studies have isolated acetaminophen-degrading pure cultures and proposed catabolic pathways, the interactions between microbiotas and acetaminophen, the distribution feature of acetaminophen degradation genes, and the gene-driven fate of acetaminophen in the real-world environment remain largely unexplored. Results Among the water samples from 20 WWTPs across China, acetaminophen was detected from 19 samples at concentrations ranging from 0.06 to 29.20 nM. However, p -aminophenol, a more toxic metabolite, was detected in all samples at significantly higher concentrations (23.93 to 108.68 nM), indicating the presence of a catabolic bottleneck in WWTPs. Metagenomic analysis from both the above 20 samples and global datasets revealed a consistently higher abundance of initial acetaminophen amidases compared to downstream enzymes, potentially having explained the reason for the bottleneck. Meanwhile, a close correlation between initial amidases and Actinomycetota revealed by genome-based taxonomy suggests a species-dependent degradation pattern. Additionally, a distinct amidase ApaA was characterized by newly isolated Rhodococcus sp. NyZ502 (Actinomycetota), represents a predominant category of amidase in WWTPs. Significant phylogenetic and structural diversity observed among putative amidases suggest versatile acetaminophen hydrolysis potential in WWTPs. Conclusions This study enhances our understanding of acetaminophen’s environmental fate and highlights the possible occurrence of ecological risks driven by imbalanced genes in the process of acetaminophen degradation in global WWTPs. Your browser is not supporting the HTML5
研究领域:
环境科学
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微生物学
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基因组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xiao-Yan Fan,Shi-Long Xu,Xing Li,Zhi-Wei Zhou,Yu-Xi Gao,Jun-Ru Zhao,Zhong-Xing Zhang
Antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) in secondary effluent from wastewater treatment plants (WWTPs) have a size-fractionated character and conventional processes have difficulties in removing ARGs and MGEs. Therefore, this study aimed to explore the removal efficiency, removal mechanism and regeneration potential of size-fractionated ARGs and MGEs by vacuum ultraviolet (VUV)-activated peroxymonosulfate (PMS) and ascertain their potential hosts in secondary effluent. The proportion of particle-associated (PA)-ARGs and PA-MGEs was 85.07 %, followed by free-living (FL) fraction (14.91 %) and cell-free (CF) fraction (0.02 %). More than 95.00 %∼99.99 % of ARGs and MGEs in PA- and CF- fractions were removed by VUV/PMS, but the average removal efficiency of FL-ARGs and FL-MGEs was 66.15 %. Compared to the regeneration potential of PA- and CF-ARGs and MGEs (0.02 < C/C 0 < 5.27), the regeneration occurred mainly in FL-ARGs and FL-MGEs (0.08 < C/C 0 < 24.06). ·OH was the dominant radical (16.810 × 10 -6 mol/L) in VUV/PMS for the removal of size-fractionated ARGs and MGEs from the secondary effluent, while SO 4 - · (4.478 × 10 -6 mol/L) played a supporting role in the system based on the quenching experiment, electron paramagnetic resonance spectrometer and probe experiments. Based on full-scale classification, conditionally rare or abundant taxa (CRAT) were the core potential hosts in PA-, FL- and CF- fractions, while rare taxa (RT) and conditionally rare taxa (CRT) potential hosts were more diverse in the three fractions. This study suggests that VUV/PMS can effectively remove size-fractionated ARGs and MGEs from secondary effluent and thereby obviously reduce their dissemination risk to receiving water bodies, providing technical support for the engineering application of VUV/PMS in full-scale WWTPs .
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Kaifeng Yu,Peng Li,Yiliang He,Bo Zhang,Yihan Chen,Jinghan Yang
Serious concerns have been raised regarding antibiotic resistance genes (ARGs) with respect to their potential threat to human health. Wastewater treatment plants (WWTPs) have been considered to be hotspots for ARGs. In this study, high-throughput quantitative polymerase chain reaction (HT-qPCR) was used to profile size-dependent ARGs and mobile genetic elements (MGEs) divided by particle-associated (PA) assemblages (>3.0-μm), free-living (FL) bacteria (0.2 - 3.0-μm) and cell-free (CF) DNA (< 0.2-μm) in two full-scale WWTPs (plants A and B) and a receiving stream. The results revealed that FL-ARGs were predominant in WWTPs and the receiving stream, especially in the final effluent of both plants. More than 40 types of CF-ARGs and CF-MGEs were detected with absolute abundances ranging from 6.0 ± 0.7 × 10 5 to 1.0 ± 0.2 × 10 8 copies/mL in wastewater, and relatively high abundances were also detected in the final effluent of the two plants, suggesting that CF-ARGs were important sources spreading from the WWTPs to the receiving environment. Plant A exhibited higher log-removal of size-fractionated ARGs and MGEs than was observed for plant B, which was attributed to the enhanced settleability of PA assemblages and FL bacteria by additional macrophytes and chemical coagulants. Ultraviolet disinfection had limited effects on ARGs and MGEs of the PA and FL fractions, which was probably ascribed to the protective matrices of the particles and cell walls. The bacterial communities of the two plants were significantly different among the size fractions ( p < 0.01). The variation partitioning analysis (VPA) indicated that the microbial community structures and MGEs contributed a variation of 68.2% in total to the relative abundance changes of size-fractionated ARGs. Procrustes analyses and Mantel tests showed that the relative abundances of ARGs were significantly correlated with bacterial community structures. These results suggested that the bacterial community structures and MGEs might have been the main drivers of the size-fractionated ARG disseminations. This study provides novel insights into size-fractionated ARGs and MGEs in full-scale WWTPs and may lead to the identification of key targets to control the spread of ARGs.
研究领域:
环境微生物学
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水处理工程
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分子生态学
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2015
·Vol. 23
·期 7
·6826-6835
·
IF 2.828
Li Jianan,Cheng Weixiao,Xu Like,Jiao Yanan,Baig Shams Ali,Chen Hong
In this study, the occurrence of 8 antibiotics [3 tetracyclines (TCs), 4 sulfonamides, and 1 trimethoprim (TMP)], 12 antibiotic resistance genes (ARGs) (10 tet , 2 sul ), 4 types of bacteria [no antibiotics, anti-TC, anti-sulfamethoxazole (SMX), and anti-double], and intI 1 in two wastewater treatment plants (WWTPs) were assessed and their influences in downstream lake were investigated. Both WWTPs’ effluent demonstrated some similarities, but the abundance and removal rate varied significantly. Results revealed that biological treatment mainly removed antibiotics and ARGs, whereas physical techniques were found to eliminate antibiotic resistance bacteria (ARBs) abundance (about 1 log for each one). UV disinfection did not significantly enhance the removal efficiency, and the release of the abundantly available target contaminants from the excess sludge may pose threats to human and the environment. Different antibiotics showed diverse influences on the downstream lake, and the concentrations of sulfamethazine (SM2) and SMX were observed to increase enormously. The total ARG abundance ascended about 0.1 log and some ARGs (e.g., tet C, intI 1, tet A) increased due to the high input of the effluent. In addition, the abundance of ARB variation in the lake also changed, but the abundance of four types of bacteria remained stable in the downstream sampling sites.
研究领域:
环境科学
·
微生物学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Jing Wang,Ling Li,Baihui Chi,Jiajia Shan,Xianliang Yi,Yang Liu,Hao Zhou
The use of disinfectants made from quaternary ammonium compounds (QACs) has greatly increased since the outbreak of SARS-CoV-2. However, the effect of QACs on wastewater treatment performance is still unclear. In this study, a commonly used QAC, i.e., benzyl dodecyl dimethyl ammonium bromide (BDAB), was added to a moving-bed biofilm reactor (MBBR) to investigate BDAB's effect on nutrient removal. When the BDAB concentration was increased to 50 mg L −1 , the ammonia removal efficiency (ARE) greatly decreased, as did the nitrate production rate constants (NPR). This inhibition was partly recovered by decreasing the BDAB concentration to 30 mg L −1 . Metagenomic sequencing revealed the functional genera present during different stages of the control (Rc) and BDAB-added reactors (Re). The enriched genera ( Rudaea , Nitrosospira , Sphingomonas , and Rhodanobacter ) in Rc mainly related to the nitrogen metabolism , while the enriched genera in Re was BDAB-concentration dependent. Functional genes analysis suggested that a lack of ammonia oxidase-encoding genes ( amo ABC) may have caused a decrease in ARE in Re, while the efflux pump-encoding genes emr E, mdf A, and opr M and a gene encoding BAC oxygenase ( oxy BAC) were responsible for BDAB resistance. The increase in the total abundance of antibiotic resistance genes (ARGs) in Re revealed a potential risk arising from BDAB. Overall, this study revealed the potential effect and ecological risks of BDAB introduction in WWTPs .
研究领域:
环境科学
·
微生物学
·
污水处理
·
宏基因组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）