Characterisation of dissolved organic matter in stormwater using high-performance size exclusion chromatography

Understanding the complexity of dissolved organic matter(DOM)in stormwater has drawn a lot of interest,since DOM from stormwater causes not only environmental impacts,but also worsens downstream aquatic quality associated with water supply and treatability.This study introduced and employed high-performance size exclusion chromatography(HPSEC)coupled with an ultraviolet–visible(UV–vis)diode array detector to assess changes in stormwater-associated DOM characteristics.Stormwater DOM was also analysed in relation to storm event characteristics,water quality and spectroscopic analysis.Statistical tools were used to determine the correlations within DOM and water quality measurements.Results showed that dissolved organic carbon(DOC)and UV absorbance at 254 nm(UV_(254))as conventional DOM parameters were found to be correlated well to the changes in stormwater quality during each of the three storm events studied.Both detector wavelengths(210and 254 nm)and their ratio(A_(210)/A_(254))were found to provide additional information on the physiochemical properties of stormwater-associated DOM.This study indicated that A_(210)/A_(254) is an important parameter which could be used to estimate the DOM proportions of functional groups and conjugated carbon species.This study provided also an understanding of stormwater quality constituents through assessing variability and sensitivity for various parameters,and the additional information of rainfall characteristics on runoff quality data for a better understanding of parameter correlations and influences.     

污水回用中主要病原菌解析及其紫外消毒效应

本研究以污水处理厂二级出水中的微生物为研究对象,通过454焦磷酸测序技术分析其群落结构组成,揭示了主要病源菌的种类和比例;通过培养法、q PCR、Q-RT-PCR这3种方法分析紫外剂量为60 m J·cm-2时对指示菌大肠杆菌和典型病原菌沙门氏菌及分枝杆菌的去除特性.结果表明,二级出水中共有11种病原菌,主要为梭菌属(2.96%)、弓形杆菌属(0.82%)和分枝杆菌(0.36%).60 m J·cm-2剂量的紫外消毒可以有效去除99.9%可培养的大肠杆菌和沙门氏菌,对可培养分枝杆菌的去除率不足90%.但是,该剂量紫外消毒对活性大肠杆菌、沙门氏菌和分枝杆菌的去除率较低,Q-RT-PCR检测方法可以较准确评价微生物的存活状态.60 m J·cm-2紫外剂量会导致大量病原菌进入具有活性但不可培养(VBNC)状态,需结合其他深度处理工艺进一步去除活性病原菌以保障污水回用的安全利用.     

Assessment of stormwater runoff management practices and governance under climate change and urbanization: An analysis of Bangkok,Hanoi and Tokyo

As human history is changing on many fronts, it is appropriate for us to understand the different perspectives of major global challenges, of which, water is a major priority. The water resources in urban areas are either approaching or exceeding the limits of sustainable use at alarming rates. Groundwater table depletion and increasing flood events can be easily realized in rapidly developing urban areas. It is necessary to improve existing water management systems for high-quality water and reduced hydro-meteorological disasters, while preserving our natural/pristine environment in a sustainable manner. This can be achieved through optimal collection, infiltration and storage of stormwater. Stormwater runoff is rainfall that flows over the ground surface; large volumes of water are swiftly transported to local water bodies and can cause flooding, coastal erosion, and can carry many different pollutants that are found on paved surfaces. Sustainable stormwater management is desired, and the optimal capture measure is explored in the paper. This study provides commentary to assist policy makers and researchers in the field of stormwater management planning to understand the significance and role of remote sensing and GIS in designing optimal capture measures under the threat of future extreme events and climate change. Community attitudes, which are influenced by a range of factors, including knowledge of urban water problem, are also considered. In this paper, we present an assessment of stormwater runoff management practices to achieve urban water security. For this purpose, we explored different characteristics of stormwater runoff management policies and strategies adopted by Japan, Vietnam and Thailand. This study analyses the abilities of Japanese, Vietnamese and Thai stormwater runoff management policies and measures to manage water scarcity and achieve water resiliency. This paper presents an overview of stormwater runoff management to guide future optimal stormwater runoff measures and management policies within the governance structure. Additionally, the effects of different onsite facilities, including those for water harvesting, reuse, ponds and infiltration, are explored to establish adaptation strategies that restore water cycle and reduce climate change-induced flood and water scarcity on a catchment scale.     

电化学消毒法对水中大肠杆菌的灭活特性

本研究通过电化学消毒小试装置,系统考察了电极板材料、极板间距、p H、水温、Na Cl浓度等因素对水中大肠杆菌CGMCC 1.3373灭活效果的影响,并进一步考察了电化学消毒对抗生素抗性大肠杆菌CGMCC 1.1595的灭活效果及其抗性变化.结果发现,在相同的电化学消毒条件下,阳极采用钌铱涂层的钛电极板的灭活效果显著优于铅涂层和铱钽涂层电极板,并且极板间距为50 mm时灭活率最高.进一步研究表明,电化学消毒法对大肠杆菌的灭活率随水的p H升高而降低,随水温和Na Cl浓度升高而升高.在相同消毒条件下,电化学法对四环素抗性大肠杆菌的灭活率显著低于普通大肠杆菌.消毒后存活的抗性菌对四环素、青霉素、氯霉素的抗性,随消毒时间延长呈现先下降后上升的规律.     

基于PMA-定量PCR选择性检测技术的病原菌消毒特性研究

建立了一种核酸染料propidium monoazide(PMA)与定量PCR技术联合选择性检测活性病原菌的技术(PMA-qPCR),以大肠杆菌作为模式菌,研究了氯和一氯胺消毒对病原菌的灭活特性.结果表明,PMA染料能够分别去除99.94%和99.99%的来自非活性大肠杆菌和沙门氏菌的DNA,PMA-qPCR技术能够有效区分活性菌与非活性菌;PMA-qPCR技术得到的氯和一氯胺消毒对大肠杆菌的灭活曲线符合一级动力学方程,灭活速率常数分别为 2.24 L·(mg·min)^-1和0.0175 L·(mg·min)^-1,低于平板培养法得到的灭活速率常数;当大肠杆菌的去除率达到99%时,采用PMA-qPCR技术检测需要的ct值相比于平板培养法从0.6 mg·L^-1·min上升到0.9 mg·L^-1·min(氯消毒)和从20 mg·L^-1·min上升到超过100 mg·L^-1·min(一氯胺消毒);随着ct值的升高,常规qPCR的检测结果基本不变,因此常规qPCR不能够反映氯和一氯胺消毒对病原菌的灭活效果.作为一种新的表征消毒特性的检测技术,PMA-qPCR技术有助于更为准确地评价氯和一氯胺消毒对病原菌的灭活效果.     

Quantitative determination of Escherichia coli based on the electrochemical measurement of bacterial catalase activity using H2O2-selective organic/inorganic-hybrid sol-gel film-modified Pt electrode

Quantitative determination of Escherichia coli (E. coli) concentration was achieved by measuring the intrinsic catalase activity of E. coli using novel H₂O₂-selective organic/inorganic-hybrid sol-gel film-modified platinum (Pt) wire electrode. This hybrid sol-gel film is composed of three kinds of organosilanes and two biopolymers (i.e., chitosan and bovine serum albumin), and exhibited an excellent permselectivity toward H₂O₂ based on a size-exclusive mechanism. The steady-state anodic current for 100 [xmol/L H₂O₂ at +0.6 V (vs. Ag/AgCl) in 0.1 mol/L phosphate buffer (pH 6.5) solution was apparently diminished by the addition of E. coli samples, due to the decomposition of H₂O₂ by intrinsic catalase activity of E. coli. The time-dependent decrease in current (–AI/At) was significantly dependent on the E. coli concentration. The –AI/At was enhanced by the permeabilization pretreatment of E. coli samples with the mixed solution of polymyxin B and lysozyme. This H₂O₂-selective organic/inorganic-hybrid sol-gel film-modified platinum (Pt) wire electrode allowed quantitative determination of E. coli concentration ranging from 10⁶ to 10⁹ CFU/mL within 30 min. This method required no label and complicated procedure, and allowed rapid, simple and cost-effective quantitative electrochemical determination of catalase-positive bacteria.     

应用FCM-qPCR方法定量检测水中常见病原体

以往对水体病原体的研究主要是通过监测粪大肠杆菌作为指示,然而研究表明粪大肠杆菌与水中病毒和细菌病原体呈现出较差的相关性.因此,选取水中典型病原体并对其进行定量检测是当前需要解决的技术问题.为此本研究建立了流式细胞术和定量PCR联合使用方法,用于快速获取水环境中总病毒、细菌以及几种典型病原体(大肠杆菌、军团菌、腺病毒、贾第虫和隐孢子虫等)的浓度水平,并将该方法应用到污水处理厂进出水及受纳河流上下游的病原体检测中.结果表明,该污水处理厂对总细菌和总病毒以及几种典型病原体都具有较高的去除率(93%);污水处理厂排水对受纳水体病原体浓度水平基本没有负面影响.研究为评估污水处理厂处理效果及排水对受纳水体的生态影响提供了技术支持.     

雨水就地处置方式的环境风险评价

雨水的就地处置正在成为一种新的处理雨水的方法，但是由于雨水径流水质的不稳定性，回灌可能会对环境产生不利的影响。因此在实施雨水回灌前需进行环境风险评价。通过对上海市雨水径流中常见污染物质含量分析（包括重金属，微生物，阴阳离子以及常规水质指标4个方面），对各种监测和实验数据进行详细分析，得出在严格控制回灌区域，保证回灌雨水水质的前提下，雨水回灌不会对环境带来不利影响的结论。     

Ecological parameters and disinfection effect of low-temperature laundering in hospitals in Slovenia

The aim of this research was to determine the influence of laundering procedures on the ecological parameters of wastewater and the electric energy consumption. Laundering procedures were simulated in a laboratory washing machine and the parameters temperature, duration and concentration of disinfection agents were varied until the optimal conditions were found for low-temperature laundering while achieving an appropriate disinfection effect with peroxyacetic acid and minimal damages to the textiles. The disinfection effect was determined using standard bioindicators Enterococcus faecium, Staphylococcus aureus, Enterobacter aerogenes and Candida albicans. The optimal low-temperature laundering procedure at 40 °C was then evaluated according to the Slovenian regulations for wastewater reuse and the toxicity of the wastewater on activated sludge as well as the wastewater biodegradability were determined. It was found that an optimal low-temperature laundering procedure at 40 °C decreased the energy consumption while reaching an adequate disinfection effect with somewhat higher dosages of chemicals and with lower damages to the textiles due to lower washing temperatures. The wastewater was found to have a certain level of pollution and was biodegradable and can therefore be treated using biological treatment.