检索结果-南通市图书馆

Influence of hydraulic retention time on behavior of antibiotics and antibiotic resistance genes in aerobic granular reactor treating biogas slurry

引用

Frontiers of Environmental Science & Engineering 2019年第3期13卷 59-67页

作者： Jie Liao Chaoxiang Liu Lin Liu Jie Li Hongyong Fan Jiaqi Ye Zhichao Zeng Key Laboratory of Environmental Biotechnology Fujian Province University Xiamen University of Technology Xiamen 361024 China Key Laboratory of Urban Pollutant Conversion Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China Fujian Institute of Innovation Chinese Academy of Sciences Fuzhou 350002 China

The behavior of antibiotics and the corresponding resistance genes in aerobic granular reactors for treating biogas slurry under different hydraulic retention times (10.7 h, Rl;8 h, R2) was investigated in this study. The results indicated that the hydraulic retention time could affect the effluent concentrations and removal efficiencies of sulfonamides. The average removal rates of tetracyclines, fluoroquinolones, and sulfonamides were 63%, 46%, and 90% in Rl, and 62%, 46%, and 86% in R2, respectively. Although the removal efficiencies of tetracyclines and fluoroquinolones were similar in both reactors, the respective accumulated concentrations of tetracyclines and fluoroquinolones in R1 were 7.00 and 11.15μg/g SS, which were lower than those in R2 (8.92 and 13.37μg/g SS, respectively). The difference in the relative abundance of target antibiotic resistance genes between both reactors was not significant, yet the average relative abundances of all target resistance genes in R1 were higher than those in R2 after 45 days of operation. The results of this study suggested that a longer hydraulic retention time could enhance the antibiotic removal ability of aerobic granular sludge, yet it may also increase the risk of surplus sludge utilization from a resistance genes point of view.

关键词： aerobic granules Swine wastewater Tetracyclines Fluoroquinolones Sulfonamides

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

aerobic dechlorination of cis- and trans-dichloroethenes by some indigenous bacteria isolated from contaminated sites in Africa

引用

Journal of Environmental Sciences 2004年第6期16卷 968-972页

作者： Ademola O. Olaniran Dorsamy Pillay Balakrishna Pillay Department of Microbiology University of Durban-Westville P. Bag X54001 Durban 4000 South AfricaDepartment of Microbiology Faculty of Science Obafemi Awolowo University Ile-Ife NigeriaDepartment of Biotechnology Durban Institute of Technology P. O. Box 1334 Durban 4000 South AfricaDepartment of Microbiology University of Durban-Westville P. Bag X54001 Durban 4000 South Africa.

The innate toxicity of dichloroethenes(DCEs) and their tendency to be reduced to vinyl chloride(VC)(a known human carcinogen) is a cause for environmental concern. aerobic bacteria capable of growth on cis- and trans-DCEs as sole carbon and energy sources were isolated by enrichment culture technique and identified to belong to the genera; Bacillus, Pseudomonas and Acinetobacter. Axenic and mixed cultures of the bacterial isolates utilized DCEs at concentrations above the maximum contaminant level allowable in drinking water by the Environmental Protection Agency. Their specific growth rate constant ranged significantly(P<0.05) between 0.346—0.552 and 0.461—0.667 d -1; while the maximum specific substrate utilization rate ranged significantly(P<0.05) between 20.01—29.79 and 31.40—42.83 nmol h -1 (mg of protein) -1 in cis- and trans-DCE, respectively. The optimum growth was observed at 30℃ and at a pH of 7.0 with up to 96% of the stoichiometric-expected chloride released. Serial adaptation positively affected the growth yields and dehalogenase activities of the organisms with multiple antibiotic patterns also demonstrated by the isolates. These findings therefore indicated the important roles that these organisms may play in the bioremediation of sites polluted with chlorinated ethene compounds in Africa.

关键词： aerobic bioremediation dichloroethenes dehalogenase polluted site

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Anaerobic-aerobic processes for the treatment of textile dyeing wastewater containing three commercial reactive azo dyes:Effect of number of stages and bioreactor type

引用

Chinese Journal of Chemical Engineering 2021年第11期34卷 228-239页

作者： Banafsheh Azimi Elham Abdollahzadeh-Sharghi Babak Bonakdarpour Chemical Engineering Department Amirkabir University of TechnologyTehranIran Environmental Group Energy DepartmentMaterials and Energy Research CenterAlborzIran

In this study,the effect of number of stages and bioreactor type on the removal performance of a sequential anaerobic-aerobic process employing activated sludge for the treatment of a simulated textile dyeing wastewater containing three commercial reactive azo dyes was *** stage processes performed better than one stage ones,both in terms of overall organic and color removal,as well as the higher contribution of anaerobic stage to the overall removal performance,thereby making them a more energy efficient *** employment of a moving bed sequencing batch biofilm reactor,which uses both suspended and attached biomass,for the implementation of the anaerobic stage of the process,was compared with a sequencing batch reactor that only employs suspended *** results showed that,although there was no meaningful difference in biomass concentration between the two bioreactors,the latter reactor had better performance in terms of chemical oxygen demand(COD)removal efficiency and rate and color removal *** exploratory tests revealed a difference between the roles of suspended and attached bacterial populations,with the former yielding better color removal whilst the latter had better COD removal *** sequential anaerobic–aerobic process,employing an aerobic membrane bioreactor in the aerobic stage resulted in COD and color removal of 77.1±7.9%and 79.9±1.5%,*** incomplete COD and color removal was attributed to the presence of soluble microbial products in the effluent and the autoxidation of dye reduction metabolites,***,aerobic partial mineralization of the dye reduction metabolites,was experimentally observed.

关键词： Wastewater Anaerobic aerobic Anaerobic moving bed sequencing batch biofilm reactor Anaerobic sequencing batch reactor aerobic membrane bioreactor

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

aerobic　EPOXIDATION　OF　STYRENE　CATALYZED　BY　MAGNESIUM　OXIDE　SUPPORTED　POLYTITAZANE　COBEST（III）　COMPLEXES

引用

Chinese Chemical Letters 1996年第8期7卷 749-752页

作者： Yuan Yong YAN Tie Jun WANG Jian Ping GUO Mei Yu HUANG Ying Yan JLANG(InstitUte of Chemistry, Academia Sinica, Beijing 100080) Institute of Chemistiy Academia Sinica Beijing 100080

Magnesium oxide supported polghtazane-cobalt (III) complex has been prepared and foundto be capable of catalyzing the epoxidaton of styrene to form styrene oxide in 88.0 % yield in thepresence of isobutyraldehyde under an atmospheric pressure of molecular oxygen at roomtemperafor. XPS data shows that the high valent cobalt (III) is stabilized by the multidentate nitrogenligand of polytitazane. Dichloroethane is the best solvent chosen for this reaction. The catalyst can bereused for several times without any remarkable loss in catalytic activity and selectivity.

关键词： III COBEST BY aerobic

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The key role of inoculated sludge in fast start-up of sequencing batch reactor for the domestication of aerobic granular sludge

引用

Journal of Environmental Sciences 2019年第4期31卷 127-136页

作者： Xiao-chun Wang Zhong-lin Chen Jing Kang Xia Zhao Ji-min Shen Liu Yang State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of Technology College of Petrochemical Technology Lanzhou University of Technology

Two types of inoculated sludges, granular sludge that had been stored at-20°C and activated sludge, were investigated for the domestication of aerobic granular sludges(AGSs in sequencing batch reactors(SBRs). The results showed that using the stored granular sludge as inoculation sludge could effectively shorten the domestication time of AGS and yielded mature granular sludge after 22 days of operation. The AGS domesticated by stored granular sludge had better biomass and sedimentation properties; its MLSS and SVI reached8.55 g/L and 35.27 mL/g, respectively. The removal efficiencies for chemical oxygen demand(COD), ammonium nitrogen(NH_4^+-N) and total phosphorus(TP) reached 90.76%, 97.39% and 96.40%, respectively. By contrast, 54 days were needed to obtain mature granules using activated sludge. The microbial community structure was probed by using scanning electron microscopy(SEM) and high-throughput sequencing. The results showed that the diversity of the microbial community in mature granules was reduced when stored granular sludge rather than activated sludge was employed as inoculation sludge, and the dominant microbes were changed. The dominant species in mature granules domesticated using stored granular sludge were Zoogloea, Acidovorax and Tolumonas at the genus classification level, while the dominant species were Zoogloea and TM7-genera in granules developed from activated sludge.

关键词： aerobic granular sludge Microbial community Sequencing batch reactor Stored granular sludge

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Metal-free visible-light-mediated aerobic oxidation of silanes to silanols

引用

Science China Chemistry 2018年第12期61卷 1594-1599页

作者： Jing Wang Bin Li Li-Chuan Liu Chenran Jiang Tao He Wei He School of Pharmaceutical Sciences Tsinghua University

Oxidation of silanes into silanols using water/air has attracted considerable attention. The known methods with no exception required a metal catalyst. Herein we report the first metal-free method: 2 mol% Rose Bengal as the catalyst, air(O2) as the oxidant, water as the additive and under visible light irradiation. While this method produces various silanols in a simple, costeffective, efficient(92%–99% yields) and scalable fashion, its reaction mechanism is very different than the reported ones associated with metal catalysis.

关键词： metal-free photoredox aerobic oxidation silanes

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Selective aerobic oxidation of p-cresol with co-catalysts between metalloporphyrins and metal salts

引用

Chinese Journal of Chemical Engineering 2018年第7期26卷 1493-1498页

作者： Yuanbin She Yao Fan Lei Zhang Ying Xu Min Yu Haiyan Fu State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology College of Chemical Engineering Zhejiang University of Technology The Modernization Engineering Technology Research Center of Ethnic Minority Medicine of Hubei Province School of Pharmaceutical Sciences South Central University for Nationalities

A green and efficient method for the selective aerobic oxidation of p-cresol to p-hydroxybenzaldehyde catalyzed by co-catalysts between metalloporphyrins and metal salts was investigated and developed. The relationship between the synergistic catalytic effects and the composition as well as amount of co-catalysts was investigated. Moreover, the influence of different reaction conditions was studied in details. A high p-cresol conversion （〉99%） and p-hydroxybenzaldehyde selectivity （83%） were obtained using only 1.125 × 10- 5 mol T（p-CH3O）PPFe111Cl-Co（OAc）2 used under mild, optimized reaction conditions. A possible mechanism for the reaction was also proposed. This work would be meaningful and instructive for the further researches and applications of co-catalyst system on oxidation of cresols and could give some enlightenment on the selectively catalytic oxidation of the side-chain alkyls of aromatics.

关键词： aerobic Oxidation Selectivity Co-catalyst Metalloporphyrin Cresols

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Strategies to improve aerobic granular sludge stability and nitrogen removal based on feeding mode and substrate

引用

Journal of Environmental Sciences 2019年第10期31卷 144-154页

作者： Quan Yuan Hui Gong Hao Xi Heng Xu Zhengyu Jin Nasir Ali Kaijun Wang State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnuironmentTsinghua Uniuersity

A systemic strategy was proposed to improve aerobic granular sludge(AGS)stability and nitrogen(N)removal efficiency by optimizing feeding mode and substrate aiming at complicated wastewater *** functional groups at the genus level identified by high-throughput sequencing were evaluated as *** results showed that anaerobic feeding mode and acetate promoted the compact AGS formation with excellent total nitrogen(TN)removal efficiency(averaging 91.7%±4.1%)at various dissolved oxygen *** the aerobic feeding mode led to a loose AGS structure with a vulnerable anaerobic core and poor TN removal efficiency(averaging58.8%±7.4%).Simultaneous nitrification and denitrification process played the dominant role in N removal in compact AGS over the alternating nitrification and denitrification ***-concentration glucose undermined feast-famine condition with filamentous bacteria growth out of granule and decreased TN removal efficiency to 67.3%±15.2%.Lower food to microorganism ratio may result in a lower N removal rate attributed to the sharply increased biomass concentration fed by ***-oxidizing bacteria,nitrite-oxidizing bacteria,denitrifying bacteria,and denitrifying phosphorus accumulation organisms enriched during AGS granulation also contributed to the efficient N *** proposed strategy provided insights into the relationship between various factors and stable AGS formation,and systemic operation methods for various complicated wastewater treatment.

关键词： aerobic granular sludge Feeding mode Substrate N removal Stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Monitoring biofouling based on aerobic respiration in reverse osmosis system

引用

Journal of Environmental Sciences 2019年第4期31卷 247-256页

作者： Youngjae Yu Keun-Young Park Jaehyun Jung Wonjung Song Jaehyeok Kim Junhee Ryu Harshad Lade Jihyang Kweon Department of Environmental Engineering Konkuk University Department of Environment and Energy Sejong University Department of Laboratory Medicine Hallym University Medical Center

A monitoring method of biofouling in reverse osmosis(RO) system was proposed based on the fluorescent signal of resorufin, which is reduced by nicotinamide adenine dinucleotide released from viable cells during aerobic respiration. The fluorescent signal of resorufin reduced by planktonic cells and microorganisms of biofilm showed linearity, indicating its feasibility to monitor biofouling in a RO system. For the application of the method to the lab-scale RO system, the injection concentration of resazurin and the injection flow rate were optimized. Biofilm on RO membranes continuously operated in a lab-scale RO system was estimated by resorufin fluorescence under optimized detection condition. As a result,resorufin fluorescence on RO membrane showed a significant increase in which the permeability of RO system decreased by 30.48%. Moreover, it represented the development of biofilm as much as conventional biofilm parameters such as adenosine triphosphate,extracellular polymeric substances, and biofilm thickness. The proposed method could be used as a sensitive and low-cost technology to monitor biofouling without autopsy of membranes.

关键词： On-site monitoring Biofilm aerobic respiration Resazurin reduction mechanism Resorufin fluorescence

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Metal-free tetra-n-butylammonium bromide-mediated aerobic oxidative synthesis of β-ketosulfones from styrenes

引用

Science China Chemistry 2017年第3期60卷 353-357页

作者： Xin Wan Kai Sun Guisheng Zhang College of Chemistry and Chemical Engineering Anyang Normal University School of Chemistry and Chemical Engineering Henan Normal University

An efficient and broadly applicable protocol for the aerobic coupling of styrenes with sulfonylhydrazides has been developed that affords P-ketosulfones bearing various functional groups in moderate to excellent *** preliminary experimental results support the involvement of active benzyl radical species,and a radical pathway was therefore proposed for the reaction.

关键词： styrenes aerobic difunctionalization ketosulfones transition metal-free conditions

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：