The Occurrence and Viability of Giardia Cysts in Scottish Raw and Final Waters

The occurrence of Giardia cysts in Scottish raw and potable waters was investigated. Giardia cysts were detected in 49% of raw waters, with concentrations of up to 1.05 cysts per litre, and in 19% of final waters, with concentrations of up to 1.67 cysts per litre. In some of the positive water samples the viability of the cysts was assessed by viewing the cyst morphology and inclusion/exclusion of propidium iodide. Viable cysts were detected in a proportion of both raw waters and positive final waters studied. Further investigations at 21 water-treatment plants revealed cysts in 9 (43%) of the raw waters, and in 4 (19%) of the final waters. Cysts were only detected in the final waters of plants in which cysts were also detected in the raw water. These data indicate that viable Giardia cysts may be ingested with potable water in Scotland.     

Analysis of long-term and seasonal river water quality changes in Latvia

An analysis of long-term historical records of the concentrations of major ions, TDS and nutrients for 20 river sites in Latvia is reported. Periods of water quality observations ranged from 15 to 43 years. A study of the quarterly adjusted time series showed that characteristic features of the data are non-normal distributions, seasonality, serial correlation and presence of significant trends that are mostly positive. The application of state-of-the-art software, based on non-parametric statistics such as the Seasonal Kendall slope estimator and the Seasonal Hodges-Lehmann estimator, made it possible to investigate these water quality records more accurately than other methods allow.Typical seasonal variations and concentration-discharge relationships were analyzed for different constituents. It was shown that fertilizer application and marsh land reclamation can cause widespread and intensive river water quality changes. Concentration increases of as much as 5–10 times that of background values were detected for NO₃⁻, Cl⁻, Na⁺ + K⁺ and SO₄²⁻. The main water quality changes took place in the 1960s and the early 1970s when fertilizer applications and reclamation works increased. After that, concentration increases for constituents other than NO₃⁻ and SO₄²⁻ were statistically insignficiant. The significant increases for NO₃⁻ and SO₄²⁻ were probably due to the additional impact of increased atmospheric deposition. The results of long-term changes of river loads entering the Baltic Sea and the Gulf of Riga from Latvian territory are examined.     

Contribution of treated wastewater to the contamination of recreational river areas with Cryptosporidium spp. and Giardia duodenalis

Samples of the influent and final effluent from 12 wastewater treatment plants from Galicia (NW, Spain) were analyzed for the presence of Cryptosporidium spp. oocysts and Giardia duodenalis cysts. All of the plants discharge effluent to a hydrographic basin in which there are numerous recreational areas and fluvial beaches. The samples (25-50 liters) were collected in spring, summer, autumn and winter of 2007. A total of 96 samples were analyzed using techniques included in the US Environmental Protection Agency Method 1623. To identify the genotypes present, the following genes were amplified and sequenced: 18S SSU rRNA (Cryptosporidium spp.) and beta-giardina (G. duodenalis). Both parasites were detected in influent and effluent samples from all treatment plants (100%) throughout the year, and G. duodenalis always outnumbered Cryptosporidium spp. The mean concentration of G. duodenalis per liter of influent was significantly higher (P<0.05) than the mean concentration of Cryptosporidium spp. per liter of influent. The mean concentrations of parasites in influent samples ranged from 6 to 350 Cryptosporidium spp. oocysts per liter and from 89 to 8305 G. duodenalis cysts per liter. In final treated effluent, the mean concentration of parasites ranged from 2 to 390 Cryptosporidium spp. oocysts per liter and from 79 to 2469 G. duodenalis cysts per liter. The distribution of results per season revealed that in all plants, the highest number of (oo)cysts were detected in spring and summer. Cryptosporidium parvum, Cryptosporidium andersoni, Cryptosporidium hominis and assemblages A-I, A-II, E of G. duodenalis were detected. The risk of contamination of water courses by Cryptosporidium spp. and G. duodenalis is therefore considerable. It is important that wastewater treatment authorities reconsider the relevance of the levels of contamination by both parasites in wastewater, and develop adequate countermeasures.     

Occurrence of Giardia cysts and Cryptosporidium oocysts in raw and treated water from two water treatment plants in Selangor, Malaysia

The occurrence of Giardia cysts and Cryptosporidium oocysts was determined both in the raw water and the treated waters from two water treatment plants in Selangor, Malaysia between July 1994 and January 1995. At each treatment plant, raw and treated water samples were collected fortnightly on 10 separate occasions. Physical parameters, including dissolved oxygen, pH, temperature, conductivity, turbidity and free and total chlorine were measured, and samples were also taken for faecal coliform analyses. The isolation and enumeration of cysts and oocysts was according to UK standard methods. Whilst Giardia cysts were detected in 90% of the raw water samples (range 0–60 cysts per litre) no Cryptosporidium oocysts were detected. Higher concentrations of cysts were detected in the raw water of the first treatment plant. All raw water samples were faecally contaminated, as faecal coliform counts ranged from 4.6 × 10⁴ to 1.3 × 10⁵ colony forming units per 100 ml. No correlation between the concentration of Giardia cysts and the concentration of faecal coliforms could be demonstrated statistically, nor was there any correlation between the concentration of Giardia cysts and the physical parameters tested for any of the raw waters. No cysts, oocysts or faecal coliforms were detected in samples of treated water.     

再生水中隐孢子虫和贾第鞭毛虫的检测方法研究

隐孢子虫和贾第鞭毛虫（简称“两虫”）是两种严重危害水质安全的病原性原生动物,但国际上常用的两虫检测方法——1623方法存在工作量大、成本高、回收率低等缺点。通过考察1623方法中浓缩、分离两个主要环节的替代方案,发现膜过滤—洗脱是比较理想的两虫浓缩方式,在免疫磁性分离（IMS）环节中酸解离比热解离的效果好。根据以上研究成果,建立了回收率较高（对两虫的回收率分别超过了30％和40％）而成本较低（为原方法的55％左右）的再生水两虫密度检测方法。进一步的研究表明,浓缩是限制低浊水（浊度约1NTU）回收率的主要步骤,而IMS是限制高浊水（浊度约4NTU）回收率的主要步骤。     

Assessment of seasonal variations in surface water quality

Assessment of seasonal changes in surface water quality is an important aspect for evaluating temporal variations of river pollution due to natural or anthropogenic inputs of point and non-point sources. In this study, surface water quality data for 16 physical and chemical parameters collected from 22 monitoring stations in a river during the years from 1998 to 2001 were analyzed. The principal component analysis technique was employed to evaluate the seasonal correlations of water quality parameters, while the principal factor analysis technique was used to extract the parameters that are most important in assessing seasonal variations of river water quality. Analysis shows that a parameter that is most important in contributing to water quality variation for one season may not be important for another season except for DOC and electrical conductance, which were always the most important parameters in contributing to water quality variations for all four seasons.     

N,N-diethyl-m-toluamide transformation in river water

The paper deals with the aqueous environmental fate of N,N-diethyl-m-toluamide (DEET), one of the most widespread and efficient mosquito repellents. The investigation involved monitoring of the DEET decomposition and the identification of intermediate compounds.Initially, control experiments in the dark and under illumination were performed on sterilized and river water spiked with DEET, with the aim to simulate all possible transformation processes occurring in aquatic system. Under illumination, DEET was degraded and transformed into numerous organic intermediate compounds, 37 of which could be identified. Several isomeric species were formed and characterized by analysing MS and MSⁿ spectra, and by comparison with parent molecule fragmentation pathways.These laboratory simulation experiments were verified in the field to check the mechanism previously supposed. River water was sampled and analysed at eight sampling points. Among the transformation products (TPs) identified in river water spiked with DEET, twelve of them were also found in natural river water. The transformation occurring in aquatic systems involved dealkylation, mono- and poly-hydroxylation followed by oxidation of the hydroxyl groups and cleavage of the alkyl chains. Two TPs were principally formed in dark condition, while the others are mainly produced through indirect photolysis processes mediated by natural photosensitizers.     

潮河流域水质分析研究

指出潮河是密云水库支柱水源，潮河的水质关系到北京人民的身体健康，采用“水质综合评价法”对潮河水质进行了分析，结果表明潮河上游水质状况良好，适合作为城市水源地水源。     

Protecting water and wastewater utilities from cyber‐physical threats

Recent events have highlighted the need to address cybersecurity threats to systems supporting critical infrastructure and federal information systems which are evolving and growing. These threats have become ubiquitous in the United States, and throughout the world. Many information and communications technology (ICT) devices and other components are interdependent so that disruption of one component may have a negative, cascading effect on others. In the United States, the Federal role in cyber‐security has been debated for more than a decade but creating a policy is complicated because in the United States, State and local governments are the major institutions responsible for providing services to their populations. It is important that critical infrastructure such as Publically Owned Treatment Works (POTWs) and Public Water Systems (PWSs) adopt suitable countermeasures to prevent or minimise the consequences of cyber‐attacks. This paper discusses both technological and procedural techniques that can be used to protect against cyber‐threats.     

某市贾第鞭毛虫和隐孢子虫污染现状

利用免疫荧光分析技术对南方某市饮用水源水、自来水厂出水和污水处理厂进、出水中贾第鞭毛虫和隐孢子虫(两虫)的污染状况进行了调查,并就自来水厂常规处理工艺对两虫的去除特性进行了研究.结果显示:该市饮用水源水中的两虫密度分别为2～120个/100L和0～24个/100 L,自来水厂出水分别为0～12个/1000 L和0～8个/1000 L,污水处理厂进水中的两虫密度分别为7 200～18 300个/L和69～1 210个/L,二级处理出水的分别为6～153个/L和1～46个/L;混凝沉淀和过滤对两虫有较好的去除效果.     

Infrastructure epistemologies: water,wastewater and displaced persons in Germany

Recent years have seen historically unprecedented global disaster migration; in 2016 Germany received 1.3 million displaced individuals. Regardless of past resources and future potential, disaster migrants are a new, vulnerable population. This new population increases demand for water and wastewater infrastructure services, despite being temporarily unable to pay for services. As such, this kind of sudden population increase is a resiliency challenge for the receiving infrastructure systems. Qualitative analysis of 1,884 open-ended survey responses was blended with a statistical analysis to discover how and why the German public perceives water and sanitation services have been provided to the disaster migrants. Unprompted, 36% (112/314) of respondents referenced at least one of three infrastructure epistemologies, including water and wastewater as a service, as a basic need, and as a human right. These epistemologies share statistically significant relationships with how long respondents feel water and wastewater should be provided to displaced persons. A temporally limited, normative perception of water and sanitation as a humanitarian good functions to enable water and wastewater infrastructure to deliver a high level of service despite the significant disruption of the large and vulnerable population influx, and has practical implications for the structure of cost recovery.     

上海市浦东自来水厂净水工艺对两虫去除效果的研究

采用免疫磁分离及荧光染色法（EPA1623法）对上海市浦东地区4家自来水厂的原水、出厂水、管网水中贾第鞭毛虫和隐孢子虫的分布状况进行了分析，并考察了水厂净水过程中不同操作单元对两虫的去除效果。研究表明：原水中存在贾第鞭毛虫与隐孢子虫，但其密度分别维持在0～8个／10L和0～6个／10L的低水平，而在出厂水与管网水中均未检出两虫；水厂的混凝、沉淀单元对两虫具有明显的去除效果。     

Occurrence and formation potential of N-nitrosodimethylamine in ground water and river water in Tokyo

N-nitrosodimethylamine (NDMA), a disinfection byproduct of water and wastewater treatment processes, is a potent carcinogen. We investigated its occurrence and the potential for its formation by chlorination (NDMA-FP_2Cl) and by chloramination (NDMA-FP_2NHCl) in ground water and river water in Tokyo. To characterize NDMA precursors, we revealed their molecular weight distributions in ground water and river water. We collected 23 ground water and 18 river water samples and analyzed NDMA by liquid chromatography-tandem mass spectrometry. NDMA-FP_2Cl was evaluated by chlorinating water samples with free chlorine for 24 h at pH 7.0 while residual free chlorine was kept at 1.0-2.0 mgCl₂/L. NDMA-FP_2NHCl was evaluated by dosing water samples with monochloramine at 140 mgCl₂/L for 10 days at pH 6.8. NDMA precursors and dissolved organic carbon (DOC) were fractionated by filtration through 30-, 3-, and 0.5 kDa membranes. NDMA concentrations were <0.5-5.2 ng/L (median: 0.9 ng/L) in ground water and <0.5-3.4 ng/L (2.2 ng/L) in river water. NDMA concentrations in ground water were slightly lower than or comparable to those in river water. Concentrations of NDMA-FP_2Cl were not much higher than concentrations of NDMA except in samples containing high concentrations of NH₃ and NDMA precursors. The increased NDMA was possibly caused by reactions between NDMA precursors and monochloramine unintentionally formed by the reaction between free chlorine and NH₃ in the samples. NDMA precursors ranged from 4 to 84 ng-NDMA eq./L in ground water and from 11 to 185 ng-NDMA eq./L in river water. Those in ground water were significantly lower than those in river water, suggesting that NDMA precursors were biodegraded, adsorbed, or volatilized during infiltration. The molecular weight of NDMA precursors in river water was dominant in the <0.5 kDa fraction, followed by 0.5-3 kDa. However, their distribution was inconsistent in ground water: one was dominant in the <0.5 kDa fraction, and the other in 0.5-3 kDa. Molecular weight distributions of NDMA precursors were very different from those of DOC. This is the first study to reveal the widespread occurrence and characterization of NDMA precursors in ground water.     

The quality of drinking water prepared from bank-filtered river water in the Netherlands

The quality of raw water and drinking water was analysed at 18 sites in the Rhine delta in an integrated program with hydrological,chemical and toxicological parameters. About 600 different organic compounds have been detected,of which about 200 could be identified,and 400 more have been classified on the basis of their mass spectra. Lipophilic compounds with a log P(octanol/water) greater than 3.2 are adsorbed during the first few meters of the bank infiltration. More hydrophilic compounds are often not adsorbed and not removed by the currently used water purification systems,such as aeration and sand filtration.The presence of organohalogens was demonstrated with surrogate parameters,such as extractable and adsorbable organohalogen. All the samples tested were mutagenic in the Ames test with strain TA98 + S9 mix. Only part of the mutagenic activity was related to compounds originating from Rhine water.     

浅谈城市季节性河流滨水景观规划

以河南省新县小潢河滨水景观规划为例，探讨了如何充分考虑规划周边功能区域、河流的季节性水位变化等影响因素，创造一个生态的、地域性的城市滨水景观，以满足人们对生活质量、生态环境的要求。     

Perspectives on multi-benefit water reuse systems: A confluence of water and wastewater management planning

The multiple benefits of water reuse have yet to be fully realized in our urban water management systems. One pathway to optimal implementation is to plan for their integration with wider assets in water resource or drainage and wastewater management plans. This paper explores the perspectives of water resource and wastewater management planners. Qualitative data was gathered from a workshop organized by the Chartered Institution for Water and Environmental Management (CIWEM) with 25 participants from England's Water Service Providers (WSPs), regulators (Ofwat and the Environment Agency) and consultants working within the UK water sector. The participants acknowledged that water reuse is relevant to both water resource and drainage and wastewater management planning, but that current regulatory and funding frameworks are constraining effective engagement between water resource and drainage and wastewater management planners by encouraging the development of separate plans. A general consensus of the participants was that it would be beneficial to include water reuse technology within current and future Water Resource Management Plans (WRMPs) and Drainage and Wastewater Management Plans (DWMPs). Participants suggested this could be developed through collaborative working partnerships and support from regulatory and funding frameworks that allow for the growth and development of innovative technologies and nature-based solutions. Participants also highlighted a stronger economic case could be made for water reuse technologies if the approach seeks to capture the wider benefits and not only the ‘best value’ solution. Societal acceptance and the availability of good quality data will be key to the successful adoption of any incentivized water reuse schemes.     

重庆市江水源热泵技术应用基础数据库建设

为研究重庆地区长江和嘉陵江江水的水温、水质、水位的年变化规律,开展了全年逐月测试。结果显示,两江水温在竖直断面上基本保持不变,相对于嘉陵江而言,长江江水温度具有夏季较低、冬季较高的特点,较嘉陵江更适合作冷热源;两江江水均要解决浊度大的水质问题,长江江水还须解决铁离子含量偏高的问题;重庆地区两江的水位变化幅度分别约为3.8,5.4m,且变化频繁。     

山区河道水面线推求中几个问题的解决方法

在对山区河道现状进行分析的基础上,以河南省林州市淅河水面线推求为例,分析了水面线推求过程中遇到的问题,提出了河道计算分段、控制水深及死水坑处理等河道水面线推求过程中的处理方法,以供参考。     

Comparison of UV-Cl and UV-H2O2 advanced oxidation processes in the degradation of contaminants from water and wastewater: A review

Applications of advanced oxidation processes (AOPs) in water and wastewater treatment have been the subject of growing interest throughout the last decade. Although UV/hydrogen peroxide (UV-H₂O₂) is the most established technology among the UV-AOPs, UV-chlorine (UV-Cl) is emerging as a reliable and potentially more cost-effective alternative. Recent studies have indicated that UV-Cl processes may be more efficient and economically favourable for the degradation of some chemicals of emerging concern from contaminated water. Moreover, in terms of the formation of disinfection by-products (DBPs), UV-H₂O₂ seems to have no superiority over UV-Cl. This said, more investigation in the assessment of genotoxicity and cytotoxicity of DBPs is required. Additionally, more pilot-scale and full-scale studies are required to establish UV-Cl as a reliable alternative to UV- H₂O₂. This paper compares UV-Cl and UV-H₂O₂ AOPs for the degradation of intractable chemicals from water and wastewater based on the practical considerations of efficiency, cost, DBP formation, kinetics and sensitivity to water matrix variability. Finally, various modelling approaches to UV-Cl have been reviewed. This review showed that UV-Cl is superior to UV-H₂O₂ in terms of degradation efficiency and cost effectiveness and can be a robust alternative in many UV-AOPs applications.