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Journal of Environmental Sciences 2016年第7期28卷 248-256页

作者： Yun Zhou Zhiqiang Zhang Jiao Zhang siqing xia Key Laboratory of Yangtze River Water Environment Ministry of Education College of Environmental Science and Engineering Tongji University State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Swette Center for Environmental Biotechnology Arizona State University School of Civil Engineering and Transportation Shanghai Technical College of Urban Management

The adsorption characteristics and mechanisms of the biosorbent from waste activated sludge were investigated by adsorbing Pb2＋and Zn2＋in aqueous single-metal solutions. A p H value of the metal solutions at 6.0 was beneficial to the high adsorption quantity of the biosorbent. The optimal mass ratio of the biosorbent to metal ions was found to be 2. A higher adsorption quantity of the biosorbent was achieved by keeping the reaction temperature below 55°C. Response surface methodology was applied to optimize the biosorption processes, and the developed mathematical equations showed high determination coefficients（above 0.99 for both metal ions） and insignificant lack of fit（p = 0.0838 and 0.0782 for Pb2＋and Zn2＋, respectively）. Atomic force microscopy analyses suggested that the metal elements were adsorbed onto the biosorbent surface via electrostatic interaction. X-ray photoelectron spectroscopy analyses indicated the presence of complexation（between –NH2,-CN and metal ions） and ion-exchange（between –COOH and metal ions）. The adsorption mechanisms could be the combined action of electrostatic interaction, complexation and ion-exchange between functional groups and metal ions.

关键词： Waste activated sludge Biosorbent Adsorption Metal ions Response surface methodology（RSM）

Simultaneous removal of selected oxidized contaminants in groundwater using a continuously stirred hydrogen-based membrane biofilm reactor

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Journal of Environmental Sciences 2013年第1期25卷 96-104页

作者： siqing xia Jun Liang xiaoyin Xu Shuang Shen State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji University

A laboratory trial was conducted for evaluating the capability of a continuously stirred hydrogen-based membrane biofllm reactor to simultaneously reduce nitrate （NO3--N）, sulfate （SO42-）, bromate （BrO3-）, hexavalent chromium （Cr（VI）） and para- chloronitrobenzene （p-CNB）. The reactor contained two bundles of hollow fiber membranes functioning as an autotrophic biofiim carder and hydrogen pipe as well. On the condition that hydrogen was supplied as electron donor and diffused into water through membrane pores, autohydrogenotrophic bacteria were capable of reducing contaminants to forms with lower toxicity. Reduction occurred within 1 day and removal fluxes for NO3--N, SO42-, BrO3-, Cr（VI）, and p-CNB reached 0.641, 2.396, 0.008, 0.016 and 0.031 g/（day.m2）, respectively after 112 days of continuous operation. Except for the fact that sulfate was 37% removed under high surface loading, the other four contaminants were reduced by over 95 %. The removal flux comparison between phases varying in surface loading and 1-12 pressure showed that decreasing surface loading or increasing 1-12 pressure would promote removal flux. Competition for electrons occurred among the five contaminants. Electron-equivalent flux analysis showed that the amount of utilized hydrogen was mainly controlled by NO3--N and SO42- reduction, which accounted for over 99% of the electron flux altogether. It also indicated the electron acceptor order, showing that nitrate was the most prior electron acceptor while sulfate was the second of the five contaminants.

关键词： oxidized contaminant groundwater simultaneous removal hydrogen-based membrane biofilm reactor

Influence and mechanism of N-(3-oxooxtanoyl)-L-homoserine lactone(C_8-oxo-HSL) on biofilm behaviors at early stage

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Journal of Environmental Sciences 2012年第12期24卷 2035-2040页

作者： siqing xia Lijie Zhou Zhiqiang Zhang Jixiang Li State Key Laboratory of Pollution Control and Resource Reuse Tongji UniversityShanghai 200092China Sustainable Technology Research Center Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China

N-acyl-homoserines quenching, enzymatic quenching of bacterial quorum sensing, has recently applied to mitigate biofilm in membrane bioreactor. However, the effect of AHLs on the behavior of biofilm formation is still sparse. In this study, Pseudomonas aeruginosa biofilm was formed on ultra-filtration membrane under a series of N-（3-0xooxtanoyl）-L-homoserine lactone （C8-0xo-HSL） concentrations. Diffusing Cs-oxo-HSL increased the growth rate of cells on biofilm where the concentration of Cs-oxo-HSL was over 10-7 g/L. The C8-0xo-HSL gradient had no observable influence on cell density and extracellular polymeric substances of biofilm with over 10-7 g/L Cs-oxo-HSL. Surprisingly, 10-11-10-8 g/L of Cs-Oxo-HSL had no effect on cell growth in liquid culture. The cell analysis demonstrated that the quorum sensing system might enhance the growth of neighboring cells in contact with surfaces into biofilm and may influence the structure and organization of biofilm.

关键词： quorum sensing C8-oxo-HSL biofilm formation ultra-filtration membrane cell density extracellular polymericsubstances

Arsenic removal from groundwater by acclimated sludge under autohydrogenotrophic conditions

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Journal of Environmental Sciences 2014年第2期26卷 248-255页

作者： siqing xia Shuang Shen xiaoyin Xu Jun Liang Lijie Zhou State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University

Arsenic in the environment is attracting increasing attention due to its chronic health effects. Although arsenite （As（III）） is generally more mobile and more toxic than arsenate （As（V））, reducing As（V） to As（III） may still be a means for decontamination, because As（III） can be removed from solution by precipitation with sulfide or by adsorption or complexation with other metal sulfides. The performance of As（V） bio-reduction under autohydrogenotrophic conditions was investigated with batch experiments. The results showed that As（V） reduction was a biochemical process while both acclimated sludge and hydrogen were essential. Most of the reduced arsenic remained in a soluble form, although 20% was removed with no addition of sulfate, while 82% was removed when sulfate was reduced to sulfide. The results demonstrated that the reduced arsenic was re-sequestered in the precipitates, probably as arsenic sulfides. Kinetic analysis showed that pseudo first-order kinetics described the bio-reduction process better than pseudo second-order. In particular, the influences of pH and temperature on As（V） reduction by acclimated sludge under autohydrogenotrophic conditions and total soluble As removal were examined. The reduction process was highly sensitive to both pH and temperature, with the optimum ranges of pH 6.5-7.0 and 30-40℃ respectively. Furthermore, Arrhenius modeling results for the temperature effect indicated that the As（V） reduction trend was systematic. Total soluble As removal was consistent with the trend of As（V） reduction.

关键词： arsenic autohydrogenotrophic bio-reduction hydrogen groundwater

Bio-reduction of nitrate from groundwater using a hydrogen-based membrane biofilm reactor

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Journal of Environmental Sciences 2010年第2期22卷 257-262页

作者： siqing xia Fohua Zhong Yanhao Zhang Haixiang Li Xin Yang State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Shanghai 200092 China College of Municipal and Environmental Engineering Shadong Jianzhu University Jinan 250101 China

A hydrogen-based membrane biofilm reactor （MBfR） using H2 as electron donor was investigated to remove nitrate from groundwater. When nitrate was first introduced to the MBfR, denitrification took place on the shell side of the membranes immediately, and the effluent concentration of nitrate continuously decreased with 100% removal rate on day 45 under the influent nitrate concentration of 5 mg NO3^--N/L, which described the acclimating and enriching process of autohydrogenotrophic denitrification bacteria. A series of short-term experiments were applied to investigate the effects of hydrogen pressures and nitrate loadings on deniWification. The results showed that nitrate reduction rate improved as H2 pressure increasing, and over 97% of total nitrogen removal rate was achieved when the nitrate loading increased from 0.17 to 0.34 g NO3^--N/（m^2.day） without nitrite accumulation. The maximum deniwification rate was 384 g N/（m^3.day）. Partial sulfate reduction, which occurred in parallel to nitrate reduction, was inhibited by denitrififcation due to the competition for H2. This research showed that MBfR is effective for removing nitrate from the contaminated groundwater.

关键词： hydrogen-based membrane biofilm reactor autotrophic denitrification nitrate groundwater

Biogenic palladium prepared by activated sludge microbes for the hexavalent chromium catalytic reduction: Impact of relative biomass

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Frontiers of Environmental Science & Engineering 2020年第2期14卷 151-159页

作者： Luman Zhou Chengyang Wu Yuwei Xie siqing xia State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Palladium,a kind of platinum group metal,owns catalytic capacity for a variety of hydrogenations.In this study,Pd nanoparticles(PdNPs)were generated through enzymatic recovery by microbes of activated sludge at various biomass/Pd,and further used for the Cr(VI)reduction.The results show that biomass had a strong adsorption capacity for Pd(II),which was 17.25 mg Pd/g sludge.The XRD and TEM-EDX results confirmed the existence of PdNPs associated with microbes(bio-Pd).The increase of biomass had little effect on the reduction rate of Pd(II),but it could cause decreasing particle size and shifting location of Pd(0)with the better dispersion degree on the cell surface.In the Cr(VI)reduction experiments,Cr(VI)was first adsorbed on bio-Pd with hydrogen and then reduced using active hydrogen as electron donor.Biomass improved the catalytic activity of PdNPs.When the biomass/Pd(w/w)ratio increased to six or higher,Cr(VI)reduction achieved maximum rate that 50 mg/L of Cr(VI)could be rapidly reduced in one minute.

关键词： Palladium nanoparticles Activated sludge Hexavalent chromium

Potential acute effects of suspended aluminum nitride (AlN) nanoparticles on soluble microbial products (SMP) of activated sludge

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Journal of Environmental Sciences 2017年第7期29卷 284-292页

作者： Lijie Zhou Weiqin Zhuang Xin Wang Ke Yu Shufang Yang siqing xia State Environmental Protection Key Laboratory of Drinking Water Source Management and Technology Shenzhen Key Laboratory of Drinking Water Source Safety ControlShenzhen Key Laboratory of Emerging Contaminants Detection & Control in Water EnvironmentShenzhen Academy of Environmental Sciences State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji University Department of Civil and Environmental Engineering University of Auckland School of Environment and Energy Peking University Shenzhen Graduate School Shenzhen Municipal Design & Research Institute Co. Ltd

The study aims to identify the potential acute effects of suspended aluminum nitride（Al N）nanoparticles（NPs） on soluble microbial products（SMP） of activated sludge.Cultured activated sludge loaded with 1,10,50,100,150 and 200 mg/L of Al N NPs were carried out in this study.As results showed,Al N NPs had a highly inverse proportionality to bacterial dehydrogenase and OUR,indicating its direct toxicity to the activated sludge viability.The toxicity of Al N NPs was mainly due to the nano-scale of Al N NPs.In SMP,Al N NPs led to the decrease of polysaccharide and humic compounds,but had slight effects on protein.The decrease of tryptophan-like substances in SMP indicated the inhibition of Al N NPs on the bacterial metabolism.Additionally,Al N NPs reduced obviously the molecular weight of SMP,which might be due to the nano-scale of Al N.

关键词： Aluminum nitride nanoparticles Topic Soluble microbial products（SMP） Activated sludge Bacterial viability

Bioreduction of vanadium(V) in groundwater by autohydrogentrophic bacteria:Mechanisms and microorganisms

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Journal of Environmental Sciences 2015年第4期27卷 122-128页

作者： xiaoyin Xu siqing xia Lijie Zhou Zhiqiang Zhang Bruce E.Rittmann State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Swette Center for Environmental Biotechnology Biodesign Institute at Arizona State University Key Laboratory of Yangtze River Water Environment Ministry of Education College of Environmental Science and EngineeringTongji University

As one of the transition metals, vanadium（V）（V（V）） in trace amounts represents an essential element for normal cell growth, but becomes toxic when its concentration is above 1 mg/L. V（V） can alter cellular differentiation, gene expression, and other biochemical and metabolic phenomena. A feasible method to detoxify V（V） is to reduce it to V（IV）, which precipitates and can be readily removed from the water. The bioreduction of V（V） in a contaminated groundwater was investigated using autohydrogentrophic bacteria and hydrogen gas as the electron donor. Compared with the previous organic donors,H2 shows the advantages as an ideal electron donor, including nontoxicity and less production of excess biomass. V（V） was 95.5% removed by biochemical reduction when autohydrogentrophic bacteria and hydrogen were both present, and the reduced V（IV）precipitated, leading to total-V removal. Reduction kinetics could be described by a first-order model and were sensitive to p H and temperature, with the optimum ranges of p H 7.5–8.0 and 35–40°C, respectively. Phylogenetic analysis by clone library showed that the dominant species in the experiments with V（V） bioreduction belonged to theβ-Proteobacteria. Previously known V（V）-reducing species were absent, suggesting that V（V）reduction was carried out by novel species. Their selective enrichment during V（V）bioreduction suggests that Rhodocyclus, a denitrifying bacterium, and Clostridium, a fermenter known to carry out metal reduction, were responsible for V（V） bioreduction.

关键词： Vanadium Bioreduction Hydrogen Rhodocyclus Clostridium

Pb(Ⅱ) removal from water using Fe-coated bamboo charcoal with the assistance of microwaves

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Journal of Environmental Sciences 2013年第5期25卷 1044-1053页

作者： Zengsheng Zhang Xuejiang Wang Yin Wang siqing xia Ling Chen Yalei Zhang Jianfu Zhao State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and EngineeringTongji University

Bamboo charcoal（BC） was used as starting material to prepare iron-modified bamboo charcoal（Fe-MBC） by its impregnation in FeCl 3 and HNO 3 solutions simultaneously,followed by microwave heating.The material can be used as an adsorbent for Pb（Ⅱ） contaminants removal in water.The composites were prepared with Fe molar concentration of 0.5,1.0 and 2.0 mol/L and characterized by means of N 2 adsorption-desorption isotherms,X-ray diffraction spectroscopy（XRD）,scanning electron microscopy coupled with energy dispersive X-ray spectrometry（SEM-EDS）,Fourier transform infrared（FT-IR） and point of zero charge（pH pzc） measurements.Nitrogen adsorption analyses showed that the BET specific surface area and total pore volume increased with iron impregnation.The adsorbent with Fe molar concentration of 2 mol/L（2Fe-MBC） exhibited the highest surface area and produced the best pore structure.The Pb（Ⅱ） adsorption process of 2Fe-MBC and BC were evaluated in batch experiments and 2Fe-MBC showed an excellent adsorption capability for removal Pb（Ⅱ）.The adsorption of Pb（Ⅱ） strongly depended on solution pH,with maximum values at pH 5.0.The ionic strength had a significant effect on the adsorption at pH 〈 6.0.The adsorption isotherms followed the Langmuir isotherm model well,and the maximum adsorption capacity for Pb（Ⅱ） was 200.38 mg/g for 2Fe-MBC.The adsorption processes were well fitted by a pseudo second-order kinetic model.Thermodynamic parameters showed that the adsorption of Pb（Ⅱ） onto Fe-MBC was feasible,spontaneous,and exothermic under the studied conditions,and the ion exchange mechanism played an significant role.These results have important implications for the design of low-cost and effective adsorbents in the removal of Pb（Ⅱ） from wastewater.

关键词： adsorption bamboo charcoal microwave assistance kinetics adsorption isotherms

Cr(VI) removal from aqueous solution with bamboo charcoal chemically modified by iron and cobalt with the assistance of microwave

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Journal of Environmental Sciences 2013年第9期25卷 1726-1735页

作者： Wei Wang Xuejiang Wang Xin Wang Lianzhen Yang Zhen Wu siqing xia Jianfu Zhao State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and Engineering Tongji University

Bamboo charcoal （BC） was used as starting material to prepare Co-Fe binary oxideloaded adsorbent （Co-Fe-MBC） through its impregnation in Co（NO3）2 , FeCl3 and HNO3 solutions simultaneously, followed by microwave heating. The low-cost composite was characterized and used as an adsorbent for Cr（VI） removal from water. The results showed that a cobalt and iron binary oxide （CoFe2O4 ） was uniformly formed on the BC through redox reactions. The composite exhibited higher surface area （331 m2/g） than that of BC or BC loaded with Fe alone （Fe-MBC）. The adsorption of Cr（VI） strongly depended on solution pH, temperature and ionic strength. The adsorption isotherms followed the Langmuir isotherm model well, and the maximum adsorption capacities for Cr（VI） at 288 K and pH 5.0 were 35.7 and 51.7 mg/g for Fe-MBC and Co-Fe-MBC, respectively. The adsorption processes were well fitted by the pseudo second-order kinetic model. Thermodynamic parameters showed that the adsorption of Cr（VI） onto both adsorbents was feasible, spontaneous, and exothermic under the studied conditions. The spent Co-Fe-MBC could be readily regenerated for reuse.

关键词： bamboo charcoal microwave adsorption hexavalent chromium