强化生物除磷体系中反硝化聚磷菌的选择与富集

采用SBR反应器 ,对以硝酸盐作为电子受体的反硝化聚磷菌的选择和富集作了研究 .结果表明 ,反硝化聚磷菌存在于传统的强化生物除磷体系之中 .经过 3个阶段的选择和富集 ,反硝化聚磷菌在聚磷菌中的比例从 15 %上升到 73% .稳定运行的强化反硝化生物除磷体系具有良好的强化生物除磷和反硝化脱氮性能 ,缺氧结束时体系中磷浓度小于 1mg L ,除磷和脱氮效率分别大于 94 %和 95 % .     

Exploring the effects of multiple management objectives and exotic species on great lakes food webs and contaminant dynamics

A simulation model was developed to describe linkages among fish food web, nutrient cycling, and contaminant processes in the southern basin of Lake Michigan. The model was used to examine possible effects of management actions and an exotic zooplankter (Bythotrephes) on Lake Michigan food web and contaminant dynamics. The model predicts that contaminant concentrations in salmonines will decrease by nearly 20% ifBythotrephes successfully establishes itself in the lake. The model suggests that this decrease will result from lowered transfer efficiencies within the food web and increased flux of contaminants to the hypolimnion. The model also indicates that phosphorus management will have little effect on contaminant concentrations in salmonines. The modeling exercise helped identify weaknesses in the data base (e.g., incomplete information on contaminant loadings and on the biomass, production, and ecological efficiencies of dominant organisms) that should be corrected in order to make reliable management decisions.     

Profiles and removal efficiency of polycyclic aromatic hydrocarbons by two different types of sewage treatment plants in Hong Kong

Sewage discharge could be a major source of polycyclic aromatic hydrocarbons(PAHs) in the coastal waters. Stonecutters Island and Shatin Sewage Treatment Works(SCISTW and STSTW)in Hong Kong, adopted chemically enhanced primary treatment and biological treatment,respectively. This study aimed at(1) determining the removal efficiencies of PAHs,(2) comparing the capabilities in removing PAHs, and(3) characterizing the profile of each individual PAHs, in the two sewage treatment plants(STPs). Quantification of 16 PAHs was conducted by a Gas Chromatography. The concentrations of total PAHs decreased gradually along the treatment processes(from 301 ± 255 and 307 ± 217 ng/L to 14.9 ± 12.1 and 63.3 ± 54.1 ng/L in STSTW and SCISTW, respectively). It was noted that STSTW was more capable in removing total PAHs than SCISTW with average total removal efficiency 94.4% ± 4.12% vs. 79.2% ± 7.48%(p 0.05). The removal of PAHs was probably due to sorption in particular matter, confirmed by the higher distribution coefficient of individual and total PAHs in solid samples(dewatered sludge contained92.5% and 74.7% of total PAHs in SCISTW and STSTW, respectively) than liquid samples(final effluent-total contained 7.53% and 25.3% of total PAHs in STSTW and SCISTW, respectively).Despite the impressive capability of STSTW and SCISTW in removing PAHs, there was still a considerable amount of total PAHs(1.85 and 39.3 kg/year, respectively for the two STPs) being discharged into Hong Kong coastal waters, which would be an environmental concern.     

去除淡水浮游藻类方法的研究进展

在春至秋季，由于环境污染的影响，我国许多湖泊和水库中经常发生水华现象。由于浮游藻类的存在以及在生长繁殖和死亡过程中所释放出的各种藻类毒素，对水生生物和人畜安全造成严重的影响。因此，必须采取科学的方法对浮游藻类予以去除。去除浮游藻类主要有物理除藻、化学除藻、生物除藻等方法。     

太原市某污水处理厂各工段重金属含量分析

以太原市某污水处理厂的实际工艺为例,采集各工段污水、污泥为样,对传统活性污泥法水处理工艺运行中的镍、镉、锌、铜的质量浓度进行了分析,结果表明,部分活性污泥回流到初沉池后发现部分重金属在沉淀池中的去除率较高.     

南宁市南湖沉积物磷释放的研究

采用室内试验模拟法对南宁市南湖沉积物进行磷的释放研究，测定南湖沉积物中磷释放速率及释放量，对影响南湖沉积物磷释放的各种环境因子进行研究。     

Alkaline phosphatase activity in the phosphorus-limited southern Chinese coastal waters

Three fractions of alkaline phosphatase activity(APA), including phytoplankton APA(phyto-APA), bacterial APA(bact-APA), and free-APA, were examined in the sea surface microlayer(SML) and the subsurface water(SSW) from Daya Bay, Guishan Island, and Guanghai Bay of southern China. Relationships between APA and environmental parameters were analyzed. The growth of phytoplankton was significantly limited by dissolved inorganic phosphorus(DIP) in the three sea areas, especially in Daya Bay. TotalAPA ranged between 1.41 and 35.26 nmol/L/hr, and the highest value was found in Daya Bay. The increased APA in Daya Bay was the result of the increase of phytoplankton biomass and the response of phytoplankton to P limitation. Phyto-APA was the main contributor in Daya Bay, while phyto-and free-APA co-dominated in Guishan Island and Guanghai Bay. Bact-, phyto-, and total-APA showed a significant inverse power function relationship with DIP, and 0.2 μmol/L was the threshold for DIP on particulates and totalAPA. Pearson correlation analysis suggested that DIP limitation together with high N levels enhanced APA. High water temperature and freshwater input accelerated APA as well.Principal component analysis clearly separated samples from the three sea areas, as well as from the SML and the SSW, which indicated the differences in environmental parameters and APA levels. Our results highlight the influence of phosphorus limitation and environmental parameters on APA.     

东海特定海区柱状沉积物中磷的存在形态及其环境指示意义

对国家海洋二所1998年5月调查过程中采自长江口外特定海区的柱状沉积物样品进行了系统的总磷及各形态磷分析。邻近长江口，杭州湾的MESO站位，总磷（TP）、铁结合态磷（Fe-P）和有机磷（OP）增色高于其它站位，表明来自长江、钱塘江水系的污染物已对东海海域的环境造成了一定影响。在垂直方向上，各站位TP、OP和Fe-P的含量自下而上增高，此外，Fe-P和OP由于还原溶解与生物降解等作用，倾向于进入孔隙水，参与海洋磷的再循环。吸附态磷（Ad-P）与钙结合态磷（Ca-P）的含量向上递减，与成岩期自生磷灰石的沉淀，以及磷的吸附-解吸附再平衡有关。     

Arsenate biotransformation by Microcystis aeruginosa under different nitrogen and phosphorus levels

The arsenate(As(V)) biotransformation by Microcystis aeruginosa in a medium with different concentrations of nitrogen(N) and phosphorus(P) has been studied under laboratory conditions. When 15 μg/L As(V) was added, N and P in the medium showed effective regulation on arsenic(As) metabolism in M. aeruginosa, resulting in significant differences in the algal growth among different N and P treatments. Under 0.2 mg/L P treatment, increases in N concentration(4–20 mg/L) significantly stimulated the cell growth and therefore indirectly enhanced the production of dimethylarsinic acid(DMA), the main As metabolite, accounting for 71%–79% of the total As in the medium. Meanwhile, 10–20 mg/L N treatments accelerated the ability of As metabolization by M. aeruginosa, leading to higher contents of DMA per cell.However, As(V) uptake by M. aeruginosa was significantly impeded by 0.5–1.0 mg/L P treatment,resulting in smaller rates of As transformation in M. aeruginosa as well as lower contents of As metabolites in the medium. Our data demonstrated that As(V) transformation by M. aeruginosa was significantly accelerated by increasing N levels, while it was inhibited by increasing P levels. Overall, both P and N play key roles in As(V) biotransformation processes.     

A review of recent substance flow analyses of phosphorus to identify priority management areas at different geographical scales

The dwindling global reserves of extractable phosphorus (P) and its growing demand to produce the required food for a burgeoning global population (the global P crisis) necessitate the sustainable use of this crucial resource. To advert the crisis requires informed policy decisions which can only be obtained by a better understanding of the nature and magnitude of P flow through different systems at different geographical scales. Through a systematic and in-depth review of twenty one recent substance flow analyses of P, we have assessed the key P inflows, outflows, stocks, internal flows, and recycling flows at the city, regional, and country scales. The assessment has revealed, the main inflow and outflow of P at the city scale occurs through food and wastewater respectively, while the main stock of P occurs in landfill. At the regional scale, mineral ore is the main P inflow and chemical P fertilizer is the main outflow particularly in the regions that have P fertilizer production sector. In contrast, either chemical P fertilizer or animal feed is the key inflow and either food and agricultural products or soil losses (erosion, runoff, and/or leaching) is the major outflow especially in the regions without P fertilizer production sector. At the country scale, the key P inflow occurs either through mineral ore or chemical P fertilizer and the key outflow takes place either as food and agricultural products, waste (both solid and liquid), or soil losses (erosion, runoff, and/or leaching). The main stock of P both at the regional and country scales occurs in the soil of the agricultural production sector. As identified in this assessment, the key unproductive outflows and stocks at different geographical scales indicate that there is a potential scope to improve P management through the increased P recovery and recycling, and by the utilization of available soil P stocks. In many of the studies at all the geographical scales, P recycling flow has been found to be less than 20% of the total inflow, and even in some studies at the country scale, P recycling has been found to be entirely absent, which is a clear indication of poor P management. This study has also identified, there is a clear knowledge gap in relation to understanding the P flow over multiple years at the regional scale. The information about the key flows and stocks at different geographical scales as we identified can be utilized to make better P policy and management decisions for a city, region, or country. The information can also be used to guide future research that aims to analyze P flow at the city, regional, and country scales.