Integrating water temperature in chlorine decay modelling: a case study

Temperature is one of the factors that most influences chlorine decay rates in drinking water systems. The current paper assesses and demonstrates the importance of using a temperature dependent chlorine bulk decay model for the accurate prediction of disinfectant residuals in water supply systems. Chlorine concentration in a water transmission system was modelled for two seasons using a temperature-dependent bulk decay model at a constant and variable temperature. Results show that water temperature can vary within the system and that the accurate prediction of residuals may additionally require the incorporation of a water temperature model in the simulators. In this case study such approach was developed innovatively by establishing a water-age-dependent temperature function.     

Evaluating emergency management capability of a water utility: A pilot study using exercise metrics

There is a societal expectation that we will still have access to essential services in the immediate aftermath of a disaster. This necessitates that utility organisations are resilient and therefore prepared for unexpected threats. One important type of preparedness activity is exercising. This research note presents findings from a pilot study in which performance evaluation metrics were developed for an emergency management exercise conducted by a water utility. Initial findings suggest that metrics and benchmarks can be successfully applied in this domain with positive implications for planning and policy across the utilities sector.     

A better water quality indexing system for rivers and streams

The development of a better system for indexing water quality and its application to four water use classes are described. There are three dominant use classes: bathing, water supply, and fish spawning, and one general use class. In all of them protection of aquatic life is included. To ensure that the index score tells us something useful and does not hide important information as current indexes (or indices) tend to do, the water quality variable giving the lowest score (i.e. the minimum operator) has been employed to produce the final index score. Preliminary indications are that this is a more useful aggregation method than the more commonly used additive, and multiplicative techniques. Index development has been linked to recommended water quality standards developed for New Zealand water legislation. The indexes are intended to assist in the dissemination of water quality information, particularly to lay-people.     

Development and validation of a drinking water temperature model in domestic drinking water supply systems

Domestic drinking water supply systems (DDWSs) are the final step in the delivery of drinking water to consumers. Temperature is one of the rate-controlling parameters for many chemical and microbiological processes and is, therefore, considered as a surrogate parameter for water quality processes. In this study, a mathematical model is presented that predicts temperature dynamics of the drinking water in DDWSs. A full-scale DDWS resembling a conventional system was built and run according to one year of stochastic demands with a time step of 10 s. The drinking water temperature was measured at each point-of-use in the systems and the data-set was used for model validation. The temperature model adequately reproduced the temperature profiles, both in cold and hot water lines, in the full-scale DDWS. The model showed that inlet water temperature and ambient temperature have a large effect on the water temperature in the DDWSs.     

Developing an integrated water management strategy to overcome conflicts between urban growth, water infrastructure and environmental quality: a case study from Ashford, Kent

Ashford, in East Kent, is a government‐designated growth area. Between 2001 and 2031, the town is set to grow by 31 000 homes and 28 000 jobs, almost doubling in size. This raises numerous concerns about the ability of the local water infrastructure and Kentish Stour catchment to accept this pressure in the short and long term. The Ashford integrated water management study (AIWMS) set out to address all the issues around water quality, water resources, biodiversity and flood risk to allow Ashford's growth to occur without unacceptable environmental damage. The study reviewed current problems with the water environment, established the key constraints to growth that might arise from the proposed development and identified water management strategies to accommodate Ashford's expansion. The paper reviews the integration methodology that was developed and discusses the lessons learned from the experience.     

Exploration of the relationship between water main breaks and temperature covariates

Water utilities (especially in colder climates) often experience an increase in water main breaks in colder seasons. Some observers argue that this increase largely occurs during the period when there are sudden and prolonged changes in water and air temperatures, which typically occur during the late fall to early winter (temperature drop) and late winter to early spring periods (temperature rise). This paper examines the impact of temperature changes on observed pipe breakage rate for three pipe materials, namely, cast iron, ductile iron and galvanised steel. Several water and air temperature-based covariates were tested in conjunction with a non-homogeneous Poisson pipe break model to assess their impact on water main breaks, using data sets from three different water utilities in the USA and Canada. Temperature-based covariates, such as average mean air temperature, maximum air temperature increase and decrease, and how fast the air temperature increase and decrease over a specific period of days, were found to be consistently significant. While the availability of water temperature data (which most utilities do not have) can enhanced the prediction of water main breaks, it appears that air temperature data alone (which most utilities can access) are usually sufficient.     

低温低浊水混凝实验研究

针对石墩子山水厂低温低浊（每年11月份至第二年4月份）的特点,对乌拉泊水库原水和乌拉泊水库原水与滤池反冲洗排水在配水井内的混合水进行混凝实验,实验表明：对于低温低浊水,PAC的最佳投加量为12mg/L,以PAM为助凝剂,除浊效果较好;PAM的投加时间对絮凝效果有较大的影响。     

MoRPh: a citizen science tool for monitoring and appraising physical habitat changes in rivers

The MoRPh survey is designed to enable citizen scientists to monitor physical habitat mosaics and human pressures within short (up to 40 m) river reaches called modules. MoRPh underpins a multiscale Modular River Survey, providing local information, which when collected across 10 contiguous modules, delivers a MultiMoRPh river sub‐reach survey up to 400 m in length. This, in turn, contributes to a HydroMoRPh assessment of reaches extending to tens of kilometres of river length, based on secondary data sources. A 6‐month trial on chalk streams, demonstrates that indices calculated from MoRPh surveys can detect notable differences in hydraulic, sediment, physical and vegetation habitat characteristics across this single river type. Further tests will evaluate applicability to other river types and ability to detect temporal changes. Development of aggregate indices for MultiMoRPh sub‐reaches will aid interpretation of contemporary morphological dynamics, complementing longer term changes extracted at the reach scale by a HydroMoRPh analysis.     

空调大温差研究（5）：空调冷水大温差系统设计方法

就冷水机组、空调机组、水泵等的选择,介绍了空调冷水大温差系统的设计方法,指出空调冷水大温差系统与常规温差的空调系统有本质区别,应选用大温差专用空调机组,采用定露点设计法,水力计算宜采用优化设计,以使冷水大温差系统获得更佳的经济性。     

In situ tests for water quality assessment: a case study in Pampean rivers

Two invertebrate species (Hyalella curvispina and Palaemonetes argentinus) and one macrophyte (Egeria densa) from a naturally high nutrient content system (Pampean rivers of La Plata, Argentina) were evaluated for their potential use in situ assays aiming to assess changes in water quality. Invertebrates were individually placed in cylindrical chambers in polluted sections of rivers and in reference upstream sites. Mortality after 48 h was high in polluted and reduced in control sites. Mortality was also higher in situ assays than in laboratory static tests. Standard sections of the macrophyte were also deployed at the reference and control sites. Growth (7 days) in terms of mass increment (but not in length) was consistently reduced in polluted sites. Results of benthic invertebrate and periphitic algae surveys were consistent with the in situ tests: pollution resulted in a decrease in the number of taxa, taxa replacement and in changes in the value of the biotic indices Indice Biótico PAMPeano and Indice de Diatomeas Pampeano, indicating deterioration of water quality. In situ assays have a high potential as environmental tools in integrated approaches of bioassessment programs.     

空调大温差研究（4）：空调冷水大温差系统经济分析

对空调冷水大温差系统的经济性进行了分析。结果表明：当冷水机组冷水初温等于或大于7℃时,10℃温差与5℃温差时冷水机组的能耗基本相同,而发器压降明显减小;冷水系统采用10℃温差较℃温差冷水量减少一半,水泵能减少,水系统一次投资减少;即使空调机组一次投资略有增加,空调水系统的一次投资可减少5％左右。空调水系统运行 费用减少30％左右。建议在应用空调大温差技术的同时使用大温差专用空调机组。     

Relationships between sand and water quality at recreational beaches

Enterococci are used to assess the risk of negative human health impacts from recreational waters. Studies have shown sustained populations of enterococci within sediments of beaches but comprehensive surveys of multiple tidal zones on beaches in a regional area and their relationship to beach management decisions are limited. We sampled three tidal zones on eight South Florida beaches in Miami-Dade and Broward counties and found that enterococci were ubiquitous within South Florida beach sands although their levels varied greatly both among the beaches and between the supratidal, intertidal and subtidal zones. The supratidal sands consistently had significantly higher (p < 0.003) levels of enterococci (average 40 CFU/g dry sand) than the other two zones. Levels of enterococci within the subtidal sand correlated with the average level of enterococci in the water (CFU/100mL) for the season during which samples were collected (r_s = 0.73). The average sand enterococci content over all the zones on each beach correlated with the average water enterococci levels of the year prior to sand samplings (r_s = 0.64) as well as the average water enterococci levels for the month after sand samplings (r_s = 0.54). Results indicate a connection between levels of enterococci in beach water and sands throughout South Florida’s beaches and suggest that the sands are one of the predominant reservoirs of enterococci impacting beach water quality. As a result, beaches with lower levels of enterococci in the sand had fewer exceedences relative to beaches with higher levels of sand enterococci. More research should focus on evaluating beach sand quality as a means to predict and regulate marine recreational water quality.     

集中空调冷却水温度与温差优化设计

针对目前集中空调系统冷却水温差大多采用5℃的情况,从经济技术的角度出发,以集中空调冷却水系统为研究对象,建立了冷却水温度与温差对冷却水系统各部分成本(初投资和运行费用)的影响的数学模型.以全年折旧费用和运行费用之和最小为目标,分析计算了冷却水温度与温差对系统各部分成本的影响,得出了最优冷却水温度和温差与电价的关系.结果显示,当电价低于或等于21元/(kWh)时,在满足机组最小流量要求的基础上,冷却水设计温差越大越好;在冷却塔其他参数既定的情况下,冷却塔出口水温越低越好.     

Sustainable water consumption and water-saving behaviours: A review of consumers' environmental and economic concerns in Turkey

Water, which plays an important role in human life, has been depleted as a result of changing consumption patterns, climate change and increasing population, and water scarcity has emerged as one of the most pressing issues facing the world in the coming years. One solution to this problem is to make more efficient and sustainable use of existing water resources. In this context, the study aims to investigate the effects of consumers' environmental and economic concerns on sustainable water consumption behaviour, as well as the mediating role of water-saving behaviour in these effects. For this purpose, it was discovered that environmental and economic concerns have positive effects on sustainable water consumption behaviour as a result of an analysis of data collected from 591 consumers in Turkey via the online survey method; it was determined that environmental concerns have no effect on water-saving behaviour, whereas economic concerns have a positive effect on water-saving behaviour. According to the findings of the mediation analysis, water-saving behaviour only serves to mediate the effect of economic concerns on sustainable water consumption behaviour.     

Relationships between visual landscape preferences and map-based indicators of landscape structure

There is increasing awareness of the need to monitor trends in our constantly changing agricultural landscapes. Monitoring programmes often use remote sensing data and focus on changes in land cover/land use in relation to values such as biodiversity, cultural heritage and recreation. Although a wide range of indicators is in use, landscape aesthetics is a topic that is frequently neglected. Our aim was to determine whether aspects of landscape content and configuration could be used as surrogate measures for visual landscape quality in monitoring programmes based on remote sensing. In this paper, we test whether map-derived indicators of landscape structure from the Norwegian monitoring programme for agricultural landscapes are correlated with visual landscape preferences. Two groups of people participated: (1) locals and (2) non-local students. Using the total dataset, we found significant positive correlations between preferences and spatial metrics, including number of land types, number of patches and land type diversity. In addition, preference scores were high where water was present within the mapped image area, even if the water itself was not visible in the images. When the dataset was split into two groups, we found no significant correlation between the preference scores of the students and locals. Whilst the student group preferred images portraying diverse and heterogeneous landscapes, neither diversity nor heterogeneity was correlated with the preference scores of the locals. We conclude that certain indicators based on spatial structure also have relevance in relation to landscape preferences in agricultural landscapes. However, the finding that different groups of people prefer different types of landscape underlines the need for care when interpreting indicator values.     

Using water consumption smart metering for water loss assessment in a DMA: a case study

ABSTRACT

In this study we analyse the benefits that may be gained from using a smart metering system to assess water losses at a district level with reference to a real case. Consumptions of all the users of this district metered area (DMA) were monitored at an hourly time step by means of electromagnetic meters. Assuming that information on water consumption was available for only a portion of users, we then estimated the water consumption of the entire DMA and calculated the error committed in this estimation as the number of available users varied. Finally, as the simultaneous hourly pattern of inflow into the DMA was also available, we used the water balance method to assess water losses. The results obtained show that monitoring even only 60% of users makes it possible to achieve an error of less than 2% in the estimation of daily consumption across the entire DMA.     

Conduction-corrected modified effective temperature as the indices of combined and separate effect of environmental factors on sensational temperature

In living spaces, people sit or lie on the floor and adopt a posture in which much of the surface of the body is in contact with the floor. When the temperature of the spatial structure or the surface temperature of an object in contact with the human body is not equivalent to the air temperature, these effects are non-negligible. Most research examining the physiological and psychological responses of the human body has involved subjects sitting in chairs. Research that takes into account body heat balance and assessments of thermal conduction into the environment is uncommon. Thus, in this study, conduction-corrected modified effective temperature (ETF), which is a new thermal environmental index incorporating heat conduction, is defined in order to make possible the evaluation of thermal environments that take into account different postures. This sensational temperature index converts the effects of the following parameters into a temperature equivalent: air velocity, thermal radiation, contact material surface temperature and humidity. This index has the features of a summation formula. Through the use of these parameters, it is possible to represent and quantify their composite influence on bodily sensation and the effects of discrete meteorological elements through an evaluation on an identical axis.     

沉淀池排泥水回用应对低温低浊水的可行性研究

根据太湖金墅原水冬季低温低浊的水质特点,探讨了采用沉淀池排泥水集中收集后回用,以期改善混凝沉淀效果的技术可行性,以及其对出水COD和余氯衰减情况的影响。结果表明,在合理控制回流比的情况下,经过深度处理后能取得预期的水质改善效果。     

变水温空调系统的运行节能分析

介绍了变水温空调系统,试验研究了变水温空调系统的节能效果。对某工程实例的理论计算结果表明,变水温运行比定水温运行可以减少大约7%～9%的运行能耗。     

浅议德令哈东山水源地保护方案及环保对策

通过对青海德令哈市饮用水水源地供水现状及供水前景分析,提出了水源地保护方案、环境保护对策及建议,以期为德令哈市社会经济的快速发展、水资源的可持续利用提供可靠保障。