Optimization of PCR-based methods for rapid detection of Campylobacter jejuni, Campylobacter coli and Yersinia enterocolitica serovar 0:3 in wastewater samples

PCR-based methods were evaluated for their adequacy to assess the removal of pathogens from wastewater samples. For the development and optimization of the methods, samples were taken at two different sites from two different constructed wetlands. Campylobacter jejuni/coli and Yersinia enterocolitica serogroup 0:3 were selected as model pathogens and Enterococcus faecalis as a standard microbiological indicator. The chosen PCR protocols were optimized for wastewater DNA extracts in order to obtain high sensitivity and reproducibility independently of the background flora. All PCR protocols were successfully performed and reproducible with a background of up to 10(10) nontarget cells per reaction. Five cells of Y. enterocolitica, 50 cells of C. jejuni/coli, and 500 cells of E. faecalis per 100ml treated water could be detected. The method detection limit in the settled wastewater was higher: 200 cells per 100ml for Y. enterocolitica, 2000 cells per 100ml for C. jejuni/coli, and 20,000 cells per 100ml for E. faecalis. C. jejuni/coli and Y. enterocolitica PCRs were adapted to municipal wastewater, with higher loads of potential PCR inhibitors. Sensitivity was lower for this type of wastewater: 200 cells of Y. enterocolitica and 2000 cells of C. jejuni/coli were detected per 100ml treated wastewater, 2500 cells of Y. enterocolitica and 25,000 cells of C. jejuni/coli per 100ml settled wastewater. The developed PCR methods enable the detection of C. jejuni/coli, Y. enterocolitica serogroup 0:3 and E. faecalis within 12h. They show specificity, reproducibility and low detection limits for the investigated pathogens.     

滴滤池/人工湿地组合工艺处理农村生活污水

为适应农村生活污水处理高效、低耗、管理简单的要求,研发了滴滤池/人工湿地组合工艺,考察了滴滤池的最佳运行参数以及改善系统脱氮除磷效果的措施.结果表明:采用该组合工艺处理农村生活污水是完全可行的,对COD、NH4 -N、TN、TP的平均去除率分别可达73.6%、89.5%、61.7%和78.4%,且运行费用仅为O.23元/m3.滴滤池的容积负荷宜控制在0.3-O.5kgCOD/(m3·d),并应使水力负荷<4.0 m3/(m2·d),适宜的回流比为2.O,布水周期为20 min.     

不同人工湿地对微污染原水处理效果的研究

采用人工湿地预处理微污染黄河原水,分别研究了推流式潜流人工湿地、往复式潜流人工湿地、芦苇床表流人工湿地、蒲草床表流人工湿地对总氮和COD的去除效果。结果表明,推流式人工湿地和往复式人工湿地对总氮和硝态氮的去除效果无明显差别,但去除率要低于表流人工湿地。蒲草床表流人工湿地对总氮和硝态氮的平均去除率分别为84．33％和76．32％,去除效果好于芦苇床表流人工湿地。各人工湿地对COD的去除率在30％-65％之间,不同人工湿地对COD的去除效果差别不明显。人工湿地处理微污染黄河原水的效果明显,出水水质可满足城市供水水源水质标准的要求。     

塔式复合人工湿地处理农村生活污水的试验研究

考察了新型人工湿地——塔式复合人工湿地（TICW）对农村生活污水的处理效果。结果表明,TICW对污染物具有较高的去除能力,脱氮效果尤其明显,对COD、NH4^＋-N、TN、TP的去除率分别为72％、82％、83％、63％;TICW的瀑布式水流增强了污水的充氧效果,湿地土壤中氨化菌、硝化菌的数量均较多,分别为10^7～10^8 CFU／g土壤和10^4～10^5 MPN／g土壤,提高了湿地的脱氮性能;木本植物和地方特有的经济作物——蔺草的结合使用使湿地在冬季仍能保持较高的除污能力。     

低氧接触氧化/微曝气人工湿地工艺净化污染河水

采用低溶解氧接触氧化与微曝气垂直流人工湿地的组合工艺对滇池入湖污染河水进行处理,以解决人工湿地在高负荷下运行时易堵塞和效率低的问题。结果表明,在低溶解氧条件下接触氧化反应器对SS、COD的平均去除率分别为86.2%和57.4%,且运行稳定。新型轮换式微曝气系统的开发与应用使垂直流人工湿地中的溶解氧环境得到了改善,悬浮物及脱落的生物膜在气流作用下不易沉降堵塞,在气水比为1∶1的条件下湿地的进水氨氮负荷可达15 g/(m2.d),平均去除率为89.6%,硝化效率明显提高。TN的去除主要依靠湿地内部的硝化/反硝化作用,轮换式曝气使溶解氧梯度随时间和空间而变化,当出水溶解氧为2~4 mg/L时,湿地单元对TN的平均去除率为40.6%。该组合工艺整体运行稳定,除污效率高,为污染河水的净化提供了一种新的方法。     

折流式人工湿地处理雨水径流的机理初步分析

针对目前人工湿地存在的问题,设计了一套新型人工湿地——折流式人工湿地床与氧化塘组合,目的是将其用于雨水的处理应用上,通过试验证明其用于处理雨水时具有良好的处理效果且运行效果稳定。     

Model-based design of horizontal subsurface flow constructed treatment wetlands: a review

The increasing application of constructed wetlands for wastewater treatment coupled with increasingly strict water quality standards is an ever growing incentive for the development of better process design tools. This paper reviews design models for horizontal subsurface flow constructed treatment wetlands, ranging from simple rules of thumb and regression equations, to the well-known first-order k-C* models, Monod-type equations and more complex dynamic, compartmental models. Especially highlighted in this review are the model constraints and parameter uncertainty. A case study has been used to demonstrate the model output variability and to unravel whether or not more complex but also less manageable models offer a significant advantage to the designer.     

建筑体型抗震性能模糊评估及其在南京民国建筑的应用

建筑体型是影响结构抗震性能的重要方面,国内外历次地震灾害表明,结构体型不规则,平面布置凸出凹入,立面造型高低错落,均不利于抗震,易造成比较严重的震害.文章从平面布置和立面造型上分析了建筑体型对结构抗震性能的影响,建立了评价指标体系,应用模糊数学方法进行建筑体型抗震性能评估,并结合一南京民国建筑加以说明.     

桃花岛面源污染示范工程的汇处理系统设计

汉阳地区桃花岛示范工程的汇处理系统是为了净化源处理系统所收集的雨水和道路排水。汇处理系统的设计包括人工湿地系统设计和多塘系统设计。人工湿地设为2组,其中,水平潜流人工湿地处理水量为560 m3/d,面积为4 500 m2;复合潜流人工湿地处理水量为700 m3/d,面积为5 200 m2。系统出水水质达到《再生水回用于景观水体的水质标准(CJ/T95—2000)》。     

对建成环境意义的逆向思考──评福建省体育运动学院场馆区构思设计

本文以Rapoport先生《建成环境的意义》的理论逆向思考为依据,阐述福建省体育运动学院场馆区的规划构思