基于区块化的供水管网全系统多级水平衡管理

介绍了我国供水管网改造相关规划等背景情况,探讨了管网改造的几个关键问题,分析了管网区块化改造的优势和实施难点,结合典型地区供水管网大型改造项目,在管网区块化布局的基础上提出了全系统多级水平衡分析的概念,可为其他城市供水管网布局改造提供技术借鉴。     

Characterization of algal organic matter and formation of DBPs from chlor(am)ination

The frequent occurrence of algal blooms in drinking water reservoirs causes problems to water supply, one of which is the release of algal organic matter in high concentrations to affect drinking water quality. Algal organic matter, including extracellular organic matter (EOM) and intracellular organic matter (IOM), was characterized. The formation of a variety of disinfection by-products (DBPs) in chlorination and chloramination of EOM, IOM and algal cells was evaluated. Natural organic matter (NOM) isolated from Suwannee River was also studied for comparison. EOM and IOM were rich in organic nitrogen, which consisted of high (over 10 kDa) and low (70–1000 Da) molecular weight (MW) organic matter, whilst the MW of organic carbon in EOM and IOM was relatively lower. IOM had a higher fraction of total organic nitrogen, with larger proportions of higher MW and more hydrophobic contents than did EOM. IOM also contained higher fractions of free amino acids but lower fractions of aliphatic amines than did EOM. During chlorination of EOM and IOM, organic chloramines were first formed and then became undetectable after 1 d. Chlorination of EOM and IOM produced more nitrogenous DBPs (N-DBPs) and haloaldehydes and less carbonaceous DBPs (C-DBPs) than did chlorination of NOM. Organic chloramines were found after 3-d chloramination of EOM and IOM. The amounts of N-DBPs and C-DBPs formed from chloramination of EOM or IOM were much less than that from NOM. EOM produced less DBPs (except for trichloronitromethane) than did IOM and algal cells in chlorination and chloramination.     

聚合铝铁强化A~2/O系统脱氮除磷研究

为了考察聚合铝铁强化A2/O除磷系统的处理效果和聚合铝铁对A2/O工艺生物系统的影响,实验模拟A2/O系统,并在其曝气池前段投加聚合铝铁,通过改变聚合铝铁的投加量,研究在不同投加量下,聚合铝铁强化A2/O除磷系统对TP,TN,COD的去除效果.并采用气相色谱法,分析检测反应器内污泥的PHA含量,研究聚合铝铁对聚磷菌的影响.结果表明:聚合铝铁对生物除磷有一定的影响,在该试验条件下,聚合铝铁的投加量为4mg/L(以Al计)进水时,系统对磷去除效果最好;同时聚合铝铁的投加也有助于TN和COD的去除.总磷去除率并不是随着聚合铝铁药剂的投加量增加而增加,而是由化学除磷和生物除磷共同作用决定.     

Bromate removal by activated carbon adsorption:material selection and impact factors study

Studies are conducted by using activated carbon process aimed at bromate removal from the raw water.Screening of activated carbon for bromate removal was performed in different activated carbons.GAC Merck possesses the highest iodine number and surface area,the highest number of basic groups and Vmeso,thereby contains the highest adsorption velocity and adsorption capacity.Impact factors of bromate removal on activated carbon were studied.Through static absorption experiments we studied the effect of adsorption time,pH,temperature,anions and organic matter on bromate removal.With the decrease of pH,removal of bromate enhanced,suggests that it may be possible to increase bromate reduction through pH control.The increase of temperature will be favorable to adsorption of bromate on activated carbon.Anions and organic matter can inhibit the adsorption of bromate on activated carbon through competing active sites.Bromate removal can be improved by controlling key water quality parameters.     

PAC-UF工艺处理沉淀池出水试验

利用粉末活性炭(PAC)和浸没式超滤膜组件联合处理净水厂沉淀池出水,并对处理前后水样的浊度、CODMn、UV254、TOC和三氯甲烷生成势进行检测.结果表明:PAC能够加强超滤膜对水中颗粒及胶体物质的控制,使出水的浊度保持在0.10NTU以下,去除率在95%以上;PAC能有效提高超滤工艺对有机物的去除能力,PAC的最佳投量在20～30mg/L;PAC和超滤膜联合使用还能去除三氯甲烷的前驱物,在投量为20～30mg/L时能降低23.9%～31.4%的三氯甲烷生成势.通过分析PAC投量对膜通量下降的影响可知,PAC投加可以降低膜污染,同时,PAC-UF工艺中形成的膜污染以粉末活性炭颗粒泥饼层为主,可以通过简单的水力反冲洗实现通量恢复。     

温度对序批式生物反应器工艺同步硝化反硝化的影响

为了考察不同温度下碳氮质量比w(C/N)和污泥龄(SRT)对同步硝化反硝化(SND)的影响,研究采用序批式生物反应器(SBR)对模拟废水进行了长期连续实验.结果表明:在pH值为7.5-8的条件下,温度为(5±1)℃,当w(C/N)为8、污泥龄为20 d时,总氮反应速率为1.25 ms/(L·h),COD去除率达到60%...     

Formation and characterization of p-type semiconductor CuCrO2 thin films prepared by a sol–gel method

This study adopted the sol–gel method to synthesize p-type semiconductor CuCrO₂ films and analyzed the effects of an annealing treatment, under a controlled argon atmosphere by changing the temperature and time, on the phase transformation, micro- and nano-structure, composition, and semiconductor properties of thin films. In the Cu–Cr–O phase transformation system, CuO, Cr₂O₃, and CuCr₂O₄ were the intermediate phases of the reaction for forming CuCrO₂: in the metastable state reaction process, the composite phases changed into a single phase, CuCrO₂; in the stable-state reaction process of CuCrO₂, carbon elements of precursors were released and eliminated; and finally the optoelectronic properties of the CuCrO₂ thin film were adjusted and changed. The CuCrO₂ thin film possessed cell- and polygon-like shaped microstructures. The carbon content in the CuCrO₂ film decreased, so the copper, chromium, and oxygen contents increased accordingly. The optical band gap of CuCrO₂ thin film increased from 2.81 eV to 3.05 eV, while the resistivity decreased. The nanoscale crystal was identified which also of the delafossite CuCrO₂ structure. Using the sol–gel method to prepare the CuCrO₂ thin films, an appropriate annealing temperature and time were helpful in forming the single-phase CuCrO₂; the decrease of precursor elements in the thin film could enhance the band gap and the conductivity of the material.     

供水管网系统不确定性分析的理论与发展

为了分析城市给水管网系统模型的不确定性,介绍了多种不确定性分析理论的应用与发展。从管网系统的复杂性入手,分析了管网系统不确定性产生的原因,从模型参数和模型结构两方面分析了管网系统模型的不确定性。介绍了GLUE、BaRE、MCMC和FOSM等不确定性分析方法的理论与进展,认为模型的不确定性分析是模型开发中必不可少的程序。     

Microbiological contamination of sheep carcases in Finland by excision and swabbing sampling

The aims of this study were to provide data on the microbiological contamination of sheep carcases slaughtered in Finland, and to compare excision and swabbing methods for microbiological sampling of sheep carcases. The results were also compared to the requirements laid down in Regulation (EC) No 2073/2005. A number of 50 sheep carcases were sampled both by excision and by swabbing with gauze at four slaughterhouses. The samples were analysed for total viable counts (TVC's), Enterobacteriaceae, and Escherichia coli. The same carcases were also sampled for Salmonella spp. by swabbing. The mean levels of TVC's and Enterobacteriaceae, and the results for Salmonella spp. were in line with the requirements laid down in Regulation (EC) No 2073/2005. The mean levels of TVC's for samples by excision and by swabbing were 3.77 log CFU/cm² and 3.16 log CFU/cm², respectively. Enterobacteriaceae were recovered from 72% and 76% of the carcases, and E. coli from 48% and 61% by excision and swabbing, respectively. No carcases were found positive for Salmonella spp. The mean levels of TVC's, Enterobacteriaceae and E. coli were significantly higher for the samples by excision than for the samples by swabbing. When the relationship between the sampling methods were analysed, the results for excision samples and swabbing samples were related for the TVC's, and there was a significant correlation between the sampling methods for Enterobacteriaceae. The results suggest that swabbing by gauze can be used as an alternative sampling method to excision. In addition, a significant correlation was seen between the results for Enterobacteriaceae and E. coli for the samples collected by swabbing, suggesting that E. coli can be used as an indicator bacterium instead for Enterobaceteriaceae for sampling of sheep carcases by swabbing.     

无排泥条件下膜生物反应器污泥混合液可滤性分析

膜生物反应器（MBR）在无排泥条件下运行100 d,定期对溶解性微生物产物（SMP）、SMP分子量分布、胞外聚合物（EPS）中的蛋白质和多糖进行监测,应用修正的污染指数（MFI）考察污泥混合液可滤性的变化。实验表明：长时间无排泥运行模式下将导致污泥混合液可滤性的恶化;污泥混合液上清液中分子量（M_w）大于10 kDa 的SMP浓度对污泥混合液的可滤性产生强烈的负面影响;污泥浓度（MLSS）与混合液可滤性之间关系复杂,MLSS对污泥可滤性的影响存在一个临界值;EPS中的蛋白质60 d后发现可被微生物迅速降解,多糖类物质对污泥混合液可滤性有较强的负面影响。