基于主成分分析和综合指数法的饮用水水源地水质评价

将主成分分析和综合指数评价法相结合,对绵阳市饮用水水源地的水质现状进行了评价。结果表明,2006--2010年饮用水水源地水质呈下降趋势,特别是2010年水质污染程度严重,主成分载荷值最大者为BOD5,重金属汞的单因子指数为2,无法满足II级水源地（III类地表水）标准要求,并根据水质污染现状,提出了相应的保护水源地水质的措施。     

The valuation of water quality: Effects of mixing different drinking water qualities

As water supplies increasingly turn to use desalination technologies it becomes relevant to consider the options for remineralization and blending with mineral rich water resources. We present a method for analyzing economic consequences due to changes in drinking water mineral content. Included impacts are cardiovascular diseases, dental caries, atopic eczema, lifetime of dish and clothes washing machines, heat exchangers, distribution systems, bottled water consumption and soap usage. The method includes an uncertainty assessment that ranks the impacts having the highest influence on the result and associated uncertainty. Effects are calculated for a scenario where 50% of Copenhagen's water supply is substituted by desalinated water. Without remineralization the total impact is expected to be negative (€−0.44 ± 0.2/m³) and individual impacts expected in the range of €0.01-0.51/m³ delivered water. Health impacts have the highest contribution to impact size and uncertainty. With remineralization it is possible to reduce several negative impacts and the total impact is expected to be positive (€0.14 ± 0.08/m³).     

Fault tree analysis for integrated and probabilistic risk analysis of drinking water systems

Drinking water systems are vulnerable and subject to a wide range of risks. To avoid sub-optimisation of risk-reduction options, risk analyses need to include the entire drinking water system, from source to tap. Such an integrated approach demands tools that are able to model interactions between different events. Fault tree analysis is a risk estimation tool with the ability to model interactions between events. Using fault tree analysis on an integrated level, a probabilistic risk analysis of a large drinking water system in Sweden was carried out. The primary aims of the study were: (1) to develop a method for integrated and probabilistic risk analysis of entire drinking water systems; and (2) to evaluate the applicability of Customer Minutes Lost (CML) as a measure of risk. The analysis included situations where no water is delivered to the consumer (quantity failure) and situations where water is delivered but does not comply with water quality standards (quality failure). Hard data as well as expert judgements were used to estimate probabilities of events and uncertainties in the estimates. The calculations were performed using Monte Carlo simulations. CML is shown to be a useful measure of risks associated with drinking water systems. The method presented provides information on risk levels, probabilities of failure, failure rates and downtimes of the system. This information is available for the entire system as well as its different sub-systems. Furthermore, the method enables comparison of the results with performance targets and acceptable levels of risk. The method thus facilitates integrated risk analysis and consequently helps decision-makers to minimise sub-optimisation of risk-reduction options.     

城市饮用水水源水质的变化特性分析

从季节性差异分析了我国东北某城市两座水源地水库的浊度、CODMn氨氮、UV254三卤甲烷生成潜能(THMFP)、叶绿素a的变化规律.结果表明,B水库原水水质要好于A水库,两座水库原水浊度、有机物和三卤甲烷前驱物含量均呈季节性变化;A水库CODMn最高值为6.5 mg/L,最低值为2.8 mg/L;B水库CODMn最高值为5.0 mg/L,全年的最低值0.5 mg/L出现在3月;B水库叶绿素a在春夏之交变化较明显,A水库和B水库六个月内叶绿素a的平均值分别为36.53和22.25 mg/m3,UV254平均值分别为0.11和0.112 cm-1.     

谈农村生活饮用水水质的影响因素

从天然背景条件与人类活动两方面,分析了影响农村饮用水水质的因素,并探讨了各因素的产生原因与作用机理,为改善我国农村生活饮用水的水质问题提供了依据。     

Assessment of the integrated urban water quality model complexity through identifiability analysis

Urban sources of water pollution have often been cited as the primary cause of poor water quality in receiving water bodies (RWB), and recently many studies have been conducted to investigate both continuous sources, such as wastewater-treatment plant (WWTP) effluents, and intermittent sources, such as combined sewer overflows (CSOs). An urban drainage system must be considered jointly, i.e., by means of an integrated approach. However, although the benefits of an integrated approach have been widely demonstrated, several aspects have prevented its wide application, such as the scarcity of field data for not only the input and output variables but also parameters that govern intermediate stages of the system, which are useful for robust calibration. These factors, along with the high complexity level of the currently adopted approaches, introduce uncertainties in the modelling process that are not always identifiable. In this study, the identifiability analysis was applied to a complex integrated catchment: the Nocella basin (Italy). This system is characterised by two main urban areas served by two WWTPs and has a small river as the RWB. The system was simulated by employing an integrated model developed in previous studies. The main goal of the study was to assess the right number of parameters that can be estimated on the basis of data-source availability. A preliminary sensitivity analysis was undertaken to reduce the model parameters to the most sensitive ones. Subsequently, the identifiability analysis was carried out by progressively considering new data sources and assessing the added value provided by each of them. In the process, several identifiability methods were compared and some new techniques were proposed for reducing subjectivity of the analysis. The study showed the potential of the identifiability analysis for selecting the most relevant parameters in the model, thus allowing for model simplification, and in assessing the impact of data sources for model reliability, thus guiding the analyst in the design of future monitoring campaigns. Further, the analysis showed some critical points in integrated urban drainage modelling, such as the interaction between water quality processes on the catchment and in the sewer, that can prevent the identifiability of some of the related parameters.     

BOD-220型快速测定仪在水质分析中的对比研究

通过实验研究,进行了不同水质、不同预处理温度下BOD-220型快速测定仪监测水质的对比分析,并对实验结果作了剖析,得到了用BOD-220型快速测定仪监测复杂水样的条件。     

Application of short-term bioassay guided chemical analysis for water quality of agricultural land run-off.

The effect of agricultural land run-off on the water quality of Lake Kojima, Japan, was investigated using a short-term bioassay-guided chemical analysis. Water samples were collected for 1 year starting from June 1995 to June 1996. Toxicity of the dissolved and adsorbed extracts in the water samples was evaluated using the Daphnia immobilization test and the concentrations of pesticides and putative toxic substance in the extracts were determined by high performance liquid chromatography. Most of the dissolved extracts caused immobilization of the test Daphnia magna at low concentrations during the period of paddy pesticide application. Some extracts were found to contain pesticides such as dymron, mefenacet and flutolanil, but their concentrations were too low to have a toxic effect on the daphnia. An unknown toxic compound, Peak C, was isolated from some river water samples, but it produced only a relatively weak toxicity to Daphnia. To better understand the impact of agricultural run-off on a receiving water body, the relationship between the observed toxicity and the concentrations of pesticides and Peak C in the water samples was studied both temporally and spatially.     

Chemical aspects of bioassay techniques for establishing water quality criteria

Increasing emphasis is being placed on the use of bioassay techniques to evaluate potential water quality problems in the aquatic environment. Although the physical environment is carefully maintained, often less emphasis is placed on maintaining the proper chemical environment in bioassay tests. Considerations of oxidation state, solubility, complexation, ionic strength, type and amount of solids, salt ratios and concentrations and organic content are essential in extrapolating the results from the test conditions to the environment. The chemical history of the test organism must be controlled to insure meaningful results, and analytical measurements should be made to insure that the proper chemical species is maintained throughout the test period. If the environmental conditions are not duplicated, studies are needed to determine how the results are dependent on the test environment used. This paper discusses examples in which changes in the chemical environment of a bioassay test may affect the results of the test and recommends procedures for minimizing problems of this type.     

建立饮用水水质监控预警系统——《饮用水水质监控预警及应急技术研究与示范项目》要点

建设监控预警系统的必要性改革开放以来,我国城市供水发展迅速,截至2008年底,655个设市城市和1615个县城供水设施规模、服务人口分别达到3.4亿m3/日、4.5亿人,比1978年提高了11.1倍和5.6倍。除部分县城和少数城市外,供水能力基本已经基本满足城市生活和生产用水需要。     

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.     

Chemical water quality in Thailand and its impacts on the drinking water production in Thailand

In Thailand, surface water and groundwater are the main water sources for tap water and drinking water production. Thirty-six different samples from surface waters from Chao Praya and Mae Klong rivers, tap waters, bottled drinking waters, groundwaters and commercial ice cubes from around the Bangkok area were collected. Water samples were also taken from two waterworks in the Chonburi province. The extensive survey showed that, overall in all water samples investigated, there was only a minor pollution which could be traced back to the analyses performed including amongst others total organic carbon, inorganics and heavy metals, pesticides, organochlorine compounds, volatile organic compounds, surfactants, pharmaceuticals and disinfection by-products. However, whenever organic micropollutants could be detected in surface water, such as, e.g. the herbicide atrazine, they were also present in the tap water produced thereof proving that the present treatment steps are not sufficient for removal of such pollutants. The concentration of disinfection by-products was higher in tap water produced from Chao Praya river than from Mae Klong river. Disinfection by-products were also found in bottled drinking water. Commercial ice cubes contained anionic surfactants and their metabolites at elevated concentrations. The data of this study constitute the first set of homogenous data for the chemical water quality and also aid development of new water quality criteria in Thailand.     

Comparative measurements of microbial activity in drinking water biofilters

Tetrazolium reduction assays, phospholipid analysis, and 16S rRNA (rDNA) sequence analysis were applied to assess the distribution, composition and activity of microbial communities developing in biofilters treating non-ozonated and ozonated drinking water. The response of media-attached biomass to both operating temperature (3 degrees C vs. > 12 degrees C) and ozone application point was assessed. As judged by 2-(p-iodo-phenyl)-3-(p-nitrophenyl)-s-phenyl tetrazolium chloride (INT) reduction, the dehydrogenase activity in biofilter systems that were operated with non-ozonated water was 55% lower than in identical filters operating with ozonated water. There was no significant difference between the microbiological activity measured in a biofilter series treating ozonated water and an identical series where ozonated water was introduced at an intermediate point. The biomass levels in biofilter systems that were operated with ozonated water were 47% higher on average than identical systems operated with non-ozonated water. Operating temperature had no significant impact on total biomass levels; however, specific dehydrogenase activity was 70% higher in systems operated at ambient temperatures (> 12 degrees C) than in systems held at 3 degrees C. Phospholipid and rDNA analysis suggests that there was a community structure response to ozone application and operating temperature, but no response to different ozone application points.     

Factors influencing the effect of bleached kraft mill effluents on drinking water quality

The taste and odour of drinking waters contaminated with bleached kraft mill effluent (BKME) were investigated. Mill effluents with a wide range of odour thresholds were selected and the effects of biological treatment, conventional water purification, carbon filtration, residual chlorine concentration, and recipient water quality were evaluated. No correlation was found between the original odour of BKME and the drinking water impairment. The taste and odour of drinking water prepared from pure glacial-fed river water to which biotreated BKMEs from three separate pulp mills were added was found to be impaired at effluent concentrations ranging from 0.1 to 0.4%. Effluent biotreatment, conventional water purification, and carbon filtration significantly reduced, but did not completely eliminate, BKME-associated taste and odour in potable water samples. The concentration of residual chlorine in the finished drinking water samples was an important factor influencing the degree of taste impairment.     

Considerations on ultra-trace analysis of phthalates in drinking water

Stir bar sorptive extraction with liquid desorption followed by large volume injection and capillary gas chromatography coupled to mass spectrometry (SBSE-LD/LVI-GC-MS), had been applied for the determination of ultra-traces of seven-phthalates (dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, butyl benzyl phthalate, bis(2-ethylhexyl) adipate, bis(2-ethylhexyl) phthalate and bis(1-octyl) phthalate) in drinking water samples, which are included in the priority lists set by several international regulatory organizations. Instrumental calibration under the selected-ion monitoring mode acquisition (LVI-GC-MS(SIM)), experimental parameters that could affect the SBSE-LD efficiency, as well as, the control of the contamination profile are fully discussed. Throughout systematic assays on 30 mL water samples spiked at the 0.40 microg/L level, it had been established that stir bars coated with 47 microL of polydimethylsiloxane, an equilibrium time of 60 min (1,000 rpm) and methanol as back extraction solvent, allowed the best analytical performance to monitor phthalates in water matrices. From the data obtained, good accuracy and a remarkable reproducibility (< 14.8%) were attained, providing experimental recovery data in agreement with the theoretical equilibrium described by the octanol-water partition coefficients (K(PDMS/W) approximately K(O/W)), with the exception of bis(2-ethylhexyl) adipate, bis(2-ethylhexyl) phthalate and bis(1-octyl) phthalate, for which lower yields were measured. Additionally, a remarkable linear dynamic range between 25 and 2,000 ng/L (r(2)>0.99) and low detection limits (3-40 ng/L) were also achieved for the seven-phthalates studied. The application of the present method to monitor phthalates in tap and bottled mineral water samples, allowed convenient selectivity and high sensitivity up to 1.0 microg/L level, using the standard addition methodology. The proposed method showed to be feasible and sensitive with a low sample volume requirement to monitor phthalates in drinking water matrices at the ultra-trace level, in compliance with international regulatory directives on water quality.     

Toxicological relevance of emerging contaminants for drinking water quality

The detection of many new compounds in surface water, groundwater and drinking water raises considerable public concern, especially when human health based guideline values are not available it is questioned if detected concentrations affect human health. In an attempt to address this question, we derived provisional drinking water guideline values for a selection of 50 emerging contaminants relevant for drinking water and the water cycle. For only 10 contaminants, statutory guideline values were available. Provisional drinking water guideline values were based upon toxicological literature data. The maximum concentration levels reported in surface waters, groundwater and/or drinking water were compared to the (provisional) guideline values of the contaminants thus obtained, and expressed as Benchmark Quotient (BQ) values. We focused on occurrence data in the downstream parts of the Rhine and Meuse river basins. The results show that for the majority of compounds a substantial margin of safety exists between the maximum concentration in surface water, groundwater and/or drinking water and the (provisional) guideline value. The present assessment therefore supports the conclusion that the majority of the compounds evaluated pose individually no appreciable concern to human health.     

Comparison of drinking water treatment process streams for optimal bacteriological water quality

Four pilot-scale treatment process streams (Stream 1 - Conventional treatment (coagulation/flocculation/dual media filtration); Stream 2 - Magnetic ion exchange (MIEX)/Conventional treatment; Stream 3 - MIEX/Conventional treatment/granular activated carbon (GAC) filtration; Stream 4 - Microfiltration/nanofiltration) were commissioned to compare their effectiveness in producing high quality potable water prior to disinfection. Despite receiving highly variable source water quality throughout the investigation, each stream consistently reduced colour and turbidity to below Australian Drinking Water Guideline levels, with the exception of Stream 1 which was difficult to manage due to the reactive nature of coagulation control. Of particular interest was the bacteriological quality of the treated waters where flow cytometry was shown to be the superior monitoring tool in comparison to the traditional heterotrophic plate count method. Based on removal of total and active bacteria, the treatment process streams were ranked in the order: Stream 4 (average log removal of 2.7) > Stream 2 (average log removal of 2.3) > Stream 3 (average log removal of 1.5) > Stream 1 (average log removal of 1.0). The lower removals in Stream 3 were attributed to bacteria detaching from the GAC filter. Bacterial community analysis revealed that the treatments affected the bacteria present, with the communities in streams incorporating conventional treatment clustering with each other, while the community composition of Stream 4 was very different to those of Streams 1, 2 and 3. MIEX treatment was shown to enhance removal of bacteria due to more efficient flocculation which was validated through the novel application of the photometric dispersion analyser.     

The effects of UV disinfection on drinking water quality in distribution systems

UV treatment is a cost-effective disinfection process for drinking water, but concerned to have negative effects on water quality in distribution system by changed DOM structure. In the study, the authors evaluated the effects of UV disinfection on the water quality in the distribution system by investigating structure of DOM, concentration of AOC, chlorine demand and DBP formation before and after UV disinfection process. Although UV treatment did not affect concentration of AOC and characteristics of DOM (e.g., DOC, UV_254, SUVA₂₅₄, the ratio of hydrophilic/hydrophobic fractions, and distribution of molecular weight) significantly, the increase of low molecular fraction was observed after UV treatment, in dry season. Chlorine demand and THMFP are also increased with chlorination of UV treated water. This implies that UV irradiation can cleave DOM, but molecular weights of broken DOM are not low enough to be used directly by microorganisms in distribution system. Nonetheless, modification of DOM structure can affect water quality of distribution system as it can increase chlorine demands and DBPs formation by post-chlorination.     

Evaluation of different analysis and identification methods for Salmonella detection in surface drinking water sources

The standard method for detecting Salmonella generally analyzes food or fecal samples. Salmonella often occur in relatively low concentrations in environmental waters. Therefore, some form of concentration and proliferation may be needed. This study compares three Salmonella analysis methods and develops a new Salmonella detection procedure for use in environmental water samples. The new procedure for Salmonella detection include water concentration, nutrient broth enrichment, selection of Salmonella containing broth by PCR, isolation of Salmonella strains by selective culture plates, detection of possible Salmonella isolate by PCR, and biochemical testing. Serological assay and pulsed-field gel electrophoresis (PFGE) can be used to identify Salmonella serotype and genotype, respectively. This study analyzed 116 raw water samples taken from 18 water plants and belonging to 5 watersheds. Of these 116, 10 water samples (8.6%) taken from 7 water plants and belonging to 4 watersheds were positive for a Salmonella-specific polymerase chain reaction targeting the invA gene. Guided by serological assay results, this study identified 7 cultured Salmonella isolates as Salmonella enterica serovar: Alnaby, Enteritidis, Houten, Montevideo, Newport, Paratyphi B var. Java, and Victoria. These seven Salmonella serovars were identified in clinical cases for the same geographical areas, but only one of them was 100% homologous with clinical cases in the PFGE pattern.