Drinking water quality at Isoko North communities of the Niger Delta Region,Nigeria

Groundwater samples from boreholes and open-hand-dug wells of six communities in the Isoko North Local Government Area of Nigeria were analyzed in respect to physicochemical factors, biological factors, and the metals Na, K, Mg, Ca, Ba, Pb, Cd, Zn, Cu, and Fe for eight consecutive months to give mean values for the wet (July to October 2010) and the dry seasons (November 2010 to February 2011) for each location. The physicochemical parameters complied with World Health Organization (WHO) guidelines, except for the pH being lower and the concentrations of Pb, Cd, and Ba, being higher than the permissible limits of WHO. Total coliform counts indicated bacterial contaminations, especially in one location. The presence of Pb in the drinking water of all communities seemed to be associated with oil exploration and processing activities.     

扫频脉冲电磁场对污水的杀菌性能

将直流脉冲与变频扫频技术相结合开发研制出扫频直流脉冲装置,利用其产生的脉冲电磁场对生活污水进行了电磁杀菌试验研究,探讨了影响杀菌效果的相关因素.试验结果表明,在扫频范围400Hz～60kHz、输出功率20W、电流1～2A条件下,脉冲电磁场对生活污水具有一定的灭菌作用,其杀菌性能随作用时间、pH值、温度、原水菌数的升高而升高.当温度为25℃,pH为7.47时,原水经电磁处理4h后,细菌总数从7.2×10⁶个·mL^-1下降到2.2×10⁴个·mL^-1,去除率为99.7%;大肠杆菌数从9.2×10⁵个·mL^-1下降到3.5×10⁴个·mL^-1,去除率为96.2%.     

快速测定水中大肠菌群的方法研究

水质常规监测中,大肠菌群的检测采用的是传统的多管发酵法,由于传统方法费时费力,在水样多及时间紧的情况下,越来越不能满足实际监测的需要,本研究工作旨在建立一种快速检测的新方法,即在初发酵管中加入一定浓度的革兰氏阳性菌抑菌剂和显色剂,直接依据产酸产气及溶液颜色的变化,推算出水样中大肠菌群的含量。通过大量对比实验,最终完成了革兰氏阳性菌抑菌剂种类、浓度和显色剂浓度的确定工作,并用所购菌种进行了对比实验,结果证明,该方法准确性较好,与传统的多管发酵法进行比对,两种方法所测结果经统计学检验无显著性差异。     

复活光照强度对再生水紫外线消毒后大肠杆菌和粪大肠杆菌光复活的影响

研究厂复活光照强度对污水三级处理出水紫外线消毒后大肠杆菌和粪大肠杆菌光复活的影响.复活光强对复活的影响依消毒时紫外线剂量及菌种的不同而不同.不同复活光强(0～43ìW/cm2)下.大肠杆菌在5 mJ/cm2的紫外线剂量消毒后,复活情况基本不受复活光强影响.紫外线剂量增高至20 mJ/cm2后复活光强存在阈值,在43 ìW/cm2复活光条件下检测到明显的光复活,低于此光强没有检测到明显的光复活.粪大肠杆菌的光复活基本不受复活光照强度的影响.复活光强对细菌光复活的不同影响在光复活控制措施提出过程中需要考虑.     

两种方法检测水中粪大肠菌群的比较

采用多管发酵法、酶底物法两种方法同时检测水中粪大肠菌群,结果表明:与传统的多管发酵法相比,两者无显著性差异,但是酶底物法具有具有操作简便,检测时间较短,特异性高,准确度高等优点,是目前比较先进的方法。     

Common Snapping Turtles (Chelydra serpentina) as a Source of Fecal Indicator Bacteria in Freshwater Systems1

Habersack, Mathew J., Theo A. Dillaha, and Charles Hagedorn, 2011. Common Snapping Turtles (Chelydra serpentina) as a Source of Fecal Indicator Bacteria in Freshwater Systems. Journal of the American Water Resources Association (JAWRA) 47(6):1255–1260. DOI: 10.1111/j.1752‐1688.2011.00572.x Abstract: The United States Total Maximum Daily Load program is required by Section 303(d) of the Clean Water Act to clean up waters that do not meet state water quality standards. While conducting research into the bacterial composition of semiaquatic mammal feces, the opportunity presented itself to quantify commonly used pathogen indicator bacteria in the gastrointestinal contents from an ectothermic (cold‐blooded) animal, the common snapping turtle. Indicator bacteria concentrations were on the order of 10⁶ CFU/g feces (dry weight basis). The estimated bacterial loadings from this study demonstrate that the common snapping turtle, if present in sufficient numbers, may contribute significant bacterial loadings to waterways and should be considered when developing bacterial Total Maximum Daily Loads and in other bacterial water quality assessments.     

Evaluation of media for simultaneous enumeration of total coliform and Escherichia coli in drinking water supplies by membrane filtration techniques

This study evaluated three different dehydrated media for simultaneous detection and enumeration of total coliform （TC） and Escherichia coil in drinking water samples with a standard membrane filtration procedure. The experiment indicated that the differential coliform agar （DCA） medium was the most effective among the tested media in enumerating TC and E. coil, without the need for extensive accompanying confirmation tests. The results for DCA medium were highly reproducible for both TC and E. coil with standard deviation of 6.0 and 6.1, respectively. A high agreement （82%） was found between DCA and m-Endo media on 152 drinking water samples in terms of TC positive. The DCA medium also reduced concealment of background bacteria.     

粪大肠菌群酶底物法在环境监测中的应用研究

粪大肠菌群作为水体粪便污染的指示菌，对地表水的水质监测评价具有重要作用。采取较为精确、快速的粪大肠菌群检测方法，对控制流行疾病的发生和传播有重要的科学意义。从粪大肠菌群的检测意义、监测方法、标准化应用情况等方面进行归纳分析，提出推广和标准化酶底物法监测粪大肠菌群的迫切性。