Journal of Ocean University of China
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2020
·Vol. 19
·期 4
·865-873
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IF 0.802
Zheng Bingbing,Pang Wenhui,Zhao Yangguo,Guo Liang,Gao Mengchun,Jin Chunji,She Zonglian
The wide application of antibiotics in aquaculture requires an efficient treatment of the wastewater before discharging it into the environment. During the wastewater treatment, the influence of antibiotics on the performance of bioreactor should be well revealed due to their toxicity to the functional microbial community. In this study, the effect of feeding 10–30 mgL −1 sulfamethoxazole (SMX) in influent on the performance of an anoxic/oxic-moving bed biofilm reactor (A/O-MBBR) treating mariculture waste-water and the responding change of biofilm microbial communities was investigated. The COD average removal rate remained at 94.61%–97.34% with the dosage of SMX. Compared with that, the nitrifying removals of NH 4 + -N and NO 2 − -N were violently inhibited by 30 mgL −1 SMX and denitrifying removal of the NO 3 − -N decreased obviously with 20 mgL −1 or more SMX. The microbial community in the successful startup bioreactor was relatively abundant, while the diversity of microbial community decreased with the increase of feeding SMX. The salt-tolerant and SMX-resistant genera Arcobacter, Thiothrix, Desulfuromusa and Nitrosomonas were gradually enriched and finally played a vital role in converting COD and recycling nitrogen and sulfur. Hence, the present A/O-MBBR reactor with the salt-tolerant functional microbiota achieved efficient removal of pollutants in the presence of low concentration (e.g., 10 mg L −1 ) SMX.
研究领域:
环境工程
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微生物学
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废水处理
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DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2019
·
IF 4.527
Sicheng Shao,Yongyou Hu,Jianhua Cheng,Yuancai Chen
In this study, the characteristics of biodegradation of oxytetracycline (OTC) by strain Ochrobactrum sp. KSS10 were studied under various environmental conditions, including initial OTC concentrations, variable temperature, initial pH, and diverse carbon sources. The capability of this bacterial strain for performing simultaneous OTC degradation and nitrate reduction was also explored under aerobic conditions . An OTC degradation ratio of 63.33% and a nitrate removal ratio of 98.64% were obtained within 96 h. In addition, removal of OTC and ammonia from synthetic aquaculture wastewater by a Moving Bed Biofilm Reactor (MBBR) and changes in the resistant genes of microbial communities were also investigated. The results demonstrated that the strain KSS10 was the dominant contributor in OTC and ammonia removal in the MBBR chamber. It removed almost all ammonia and approximately 76.42% of OTC. The abundances of genes tet L, tet X and intI 1 were reduced by the MBBR, but the abundance of tet G and tet M were increased due to horizontal and vertical gene transfers. Such a result can potentially be used by the strain KSS10 for removing antibiotics and nitrogen from aquaculture wastewater during pre-treatment.
研究领域:
环境工程
·
微生物学
·
废水处理
·
水产养殖
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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
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微生物学
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污水处理
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宏基因组学
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产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2019
·
IF 5.589
Changwei Li,Lihua Lan,Musa Abubakar Tadda,Songming Zhu,Zhangying Ye,Dezhao Liu
This study investigated the relation between 17 β -estradiol (E2) degradation and nitrification in synthetic mariculture wastewater by ammonia oxidizing bacterium Nitrosomonas europaea and moving bed biofilm reactor (MBBR). Batch experiments showed that E2 degradation by N. europaea in wastewater followed zero-order reaction kinetics (r 2 = 0.944, 4.07 μg/ L h − 1 ) when ammonia presented. Nitrite yield in N. europaea inoculation decreased by 77.8% exposed to 1 mg/L E2. The inhibitory impact on ammonia oxidation was enhanced with increasing E2 dosage from 50 ng/L to 1 mg/L. Notably, E2 as low as 50 ng/L still had significant interference with nitrite production, bacterial density and ammonia monooxygenase (AMO) activity of N. europaea . Still, the following continuous 68-day degradation test revealed that 84.5%–98.7% E2 could be removed by a bench-scale MBBR. Whereas, ammonia removal remarkably decreased from 94.7% ± 2.1% to 85.6% ± 2.1% ( p < .05) along with the enhanced E2 removal (from 84.5% ± 2.0% to 98.7% ± 0.4%, p < .05) when inlet E2 increased from 10 μg/L to 1 mg/L, indicating the great role of heterotrophs in E2 degradation. In contrast, nitrite oxidation was not affected upon E2 exposure irrespective of E2 concentrations. In summary, nitrification was effective in removing E2, while E2 interfered with ammoxidation process, but this interference was negligible at the reactor level given the low level of E2 in practical field conditions.
研究领域:
环境工程
·
微生物学
·
废水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
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2022
·
IF 11.072
Zi Song,Runfeng Liao,Mingming Wang,Jianjun Zhang,Zijun Dong,Zheng Wen,Wenyi Dong,Feiyun Sun
Biofilm formation is a complex and time-consuming process, especially the attachment and growth of anaerobic biofilm, which fundamentally determines the start-up of biofilm reactor . In this study, biosurfactant, rhamnolipid, was introduced into an anaerobic moving bed biofilm reactor (AnMBBR) to promote its start-up, and the results showed that AnMBBR with rhamnolipid (RMBBR) could be successfully started within 25 days. Compared to the control AnMBBR without rhamnolipid, the start-up time was shortened by about half, the attached biomass on biocarriers was increased to 1.5 times, and the pollutants removal efficiencies were all greatly improved in the start-up phase, especially NO 3 − increased from 86.76 ± 1.04% to 96.93 ± 0.73%, and then these gaps were reduced in the steady-state phase. Under the action of rhamnolipid, the adhesion force of the biofilm increased from 18.9 nN to 27.4 nN eventually, and the interfacial energy between biofilm and biocarriers was transformed from repulsion (6200 KT) to weak attraction (−100 KT) by the evaluation of the extended Derjaguin–Landau–Verwey–Overbeek theory, which significantly promoted the initial attachment of biofilm. The increased metabolic activity , key enzyme activity, extracellular polymeric substances (EPS) and quorum sensing behaviors evidenced that rhamnolipid stimulated microbial internal activities and then regulated biofilm growth process. Moreover, rhamnolipid also significantly enhanced the abundance of functional bacteria in terms of metabolism or quorum sensing, including Thauera , Methylomonas , Desulfomicrobium , Azoarcus , Leptonema . Rhamnolipid would also stimulate the expression of genes that related to membrane transport, biofilm formation and nitrogen metabolism . This work provided a promising strategy for the rapid start-up of anaerobic biofilm reactor.
研究领域:
环境工程
·
微生物学
·
生物技术
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DOI
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Chunyan Li,Zhenlei Yue,Fengzhao Feng,Chuanwu Xi,Hailian Zang,Xuejiao An,Keran Liu
There is a great need for efficient acetonitrile removal technology in wastewater treatment to reduce the discharge of this pollutant in untreated wastewater. In this study, a nitrilase gene ( nit ) isolated from a nitrile-degrading bacterium ( Rhodococcus rhodochrous BX2) was cloned and transformed into a biofilm-forming bacterium ( Bacillus subtilis N4) that expressed the recombinant protein upon isopropylthio-β-galactoside (IPTG) induction. The recombinant bacterium ( B. subtilis N4-pHT01- nit ) formed strong biofilms and had nitrile-degrading capability. Further testing demonstrated that biofilms formed by B. subtilis N4-pHT01- nit were highly resistant to loading shock from acetonitrile and almost completely degraded the initial concentration of acetonitrile (800 mg L −1 ) within 24 h in a moving bed biofilm reactor (MBBR) after operation for 35 d. The bacterial composition of the biofilm, identified by high-throughput sequencing, in a reactor in which the B. subtilis N4-pHT01- nit bacterium was introduced indicated that the engineered bacterium was successfully immobilized in the reactor and became dominant genus. This work demonstrates that an engineered bacterium with nitrile-degrading and biofilm-forming capacity can improve the degradation of contaminants in wastewater. This approach offers a novel strategy for enhancing the biological oxidation of toxic pollutants in wastewater.
研究领域:
环境工程
·
微生物学
·
生物技术
·
污水处理
✓ 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）