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the muddy water. The floodgates will be open to disembogue water and desilting, the water lever will drop
to 145 meters during the flood season, and the water lever will be risen to 175 meters after the flood
season, this process will form hydro-fluctuation belt with a drop of 30 meters in maximum water level in
the areas along the river. It is also a gallery for exchange things and energy between land and water
system. Nowadays, environmental pollution is aggravating, the destruction of bio-diversity, healthy
problems of people, and geological disaster around the hydro-fluctuation belt, these problems happen
occasionally. However, the ecological health risk assessment and prediction is still in testing and groping
stage. This paper tried to make a study from ecological processes to landscape and hydro-fluctuation belt
scale. It combined remote sensing(RS), geographical information system(GIS) and principle of landscape
ecology methods. The study utilized with the methodology on combination of microscopic and
macroscopic, established comprehensive evaluation index system, which selected some categories such
as ecology, physical chemistry, social economy and human health. Model was set up and used to assess
and predict ecological health risk of the hydro-fluctuation belt. The comparison between the results of
assessment and prediction and real condition indicted that this method is accurately and effectively.
Keywords: hydro-fluctuation belt; GIS and RS; ecological health; assessment and prediction
Microbial reduction and precipitation of vanadium (V) by autohydrogentrophic
microorganisms
Xiaoyin Xu, Siqing Xia*, Shuang Shen, Jun Liang, Lijie Zhou, Zhiqiang Zhang
徐 晓 茵 , 夏 四 清 *, 沈 双 , 梁 郡 , 周 礼 杰 , 张 志 强
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science
and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; *Corresponding
author. Tel.: +86 21 65980440; +86 21 65984268. E-mail address: siqingxia@gmail.com,
1040050012@tongji.edu.cn.
Abstract: As one of transition metals, vanadium (V) in trace amounts represents an essential element for
normal cell growth, but becomes toxic when its concentration is at the ppm level. It can increase cellular
differentiation, gene expression alterations, and other biochemical and metabolic alterations. In China,
the vanadium concentration in drinking water is limited to below 0.05 mg/L (GB 5749-2006).
The bioreduction of oxidized V(V) in a contaminated groundwater was investigated using
autohydrogentrophic bacteria and hydrogen gas as the electron donor. Three controls (without biomass,
without H2, and without vanadium) were carried out in parallel to ensure that all reactions were
biologically mediated. In the abiotic control (no inoculum), the influent V(V) was unchanged, indicating
the chemical reduction of V(V) by H2 was infeasible. In the control without H2 (N2 replaced H2), the
removal percentage of total soluble vanadium was only 3%, showing that endogenous respiration and
adsorption to biomass caused minimal removal of vanadium. The V(IV) concentration in the no-H2
control was almost zero, also indicated that V(V) was not reduced without an added electron donor.
Neither V(V) nor V(IV) was detected in the control with no vanadium addition. V(V) was 95.5% removed
by biochemical reduction when autohydrogentrophic bacteria and hydrogen were present, and the
reduced V(IV) precipitated, leading to total-V removal. Reduction kinetics could be described by the firstorder
model. Bioreduction was sensitive to pH and temperature, with the optimum ranges of pH 7.5-8.0
and 35-40oC, respectively. Phylogenetic analysis by clone library showed that the dominant species
belonged to the β-Proteobacteria. V(V)-reduction was speculated to be carried out by novel species or
known denitrification bacteria via a secondary-utilization mechanism.
Keywords: Vanadium, Groundwater, Bioreduction, Autohydrogenotrophic microorganisms, Hydrogen
Emission of greenhouse gases and airborne bacteria from a wastewater treatment plant using
oxidation ditch
Xu Yan, Lin Li, Junxin Liu
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085,
China, Email: yanxu119@126.com, leel@rcees.ac.cn, jxliu@rcees.ac.cn
Abstract: Wastewater treatment plants (WWTPs) are regarded as sources of greenhouse gases (GHGs)
and airborne microorganisms. In this study, carbon dioxide (CO2), methane (CH4) and nitrous oxide
(N2O) as well as airborne bacteria were investigated from March to October in 2010 in a Beijing municipal
wastewater treatment plant with Orbal oxidation ditch process. The CO2 emission was found to be
connected with sludge retention time (SRT) and BOD of influent water. CH4 generated mainly from the
dissolved CH4 brought by influent and its stripping from water could be promoted obviously by the
mechanical motion of rotating brushes. SRT and water temperature were the major parameters on N2O
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