Financial sustainability of rural water supply: An analysis of cost recovery,revenue collection,and efficiency

Maintaining a financial sustainable pipe water supply (PWS) is one of the serious challenges in sustainable provision of water supply in rural areas. Poor revenue collection and willingness to pay for the service is adding severity to the problem. This study analyses the factors affecting revenue collection in rural water utilities and measures its efficiency in maximizing revenue and average hour of water supply per day. The findings convey that cost recovery is a failure in rural water supply even they are not able to generate revenue. Inactive community participation, the notion of free water supply, unaccountable payment is main reason for poor revenue collection. Therefore, active community participations, educating the household on water supply, adoption of accountable payment mode will be a step towards revenue generation. To attain efficiency, the utilities can expand their output revenue and hours of water supply by 22% without altering their input. This study is an empirical contribution in the field of sustainable provision of water supplies, which address the problem of poor revenue generation in rural water supply and find out the reason for it.     

建筑给排水专业节能措施及再生水资源的利用

结合国家节能减排目标和保护环境战略,从给排水专业角度阐述了具体的节能减排措施,包括采用管网叠压供水设备、太阳能,做好保温措施等,并对污废水及雨水的再生利用进行了探讨,以期指导实践,从而科学有效地节能减排。     

The water supply is fine: decision‐maker perceptions of water quantity and supply‐side management

Years of research have called for more science to be integrated into water management decisions and for a shift from supply‐side to demand‐side management; yet, there remains a strong emphasis on supply‐side approaches and in many areas limited attention to hydrological data. A survey and interviews with decision‐makers in western North Carolina reveal that there is only low‐level concern about water quantity, and this drives a continued emphasis on supply‐side management and no perceived need for hydrological data. The historical realities of low demand and abundant water have generated a perception of ‘water supply’ as disconnected from physical, hydrological systems and allowed for ad hoc decision‐making processes to prevail. The lack of well‐established processes may, ironically, provide significant opportunities for employing collaboration among researchers and decision‐makers to develop policies and processes that integrate data into making water management decisions and thus prompt increased attention to water demand.     

Solar-based atmospheric water generator utilisation of a fresh water recovery: A numerical study

In many regions in the world, the climate conditions are suitable for generating drinkable water; however, they have one or more types of water scarcity. An alternative method for fresh water recovery from atmosphere had been studied in this paper. The studied method is designed for Arabic Gulf countries or similar by using solar-based thermoelectric generator utilisation. The existence of solar energy and humid air gives a good chance for effective productivity. Nowadays, the mathematical model is able to give a good representation of the different cases. The use of recent numerical modelling is robust enough to give accurate results with cost and time saving. For simplification; the cases in this paper were supposed to be the fluid flow region, it means that the simulation will not be involved in the multi physics. The cases have been simulated in 3D using commercial CFD software called Star-CCM+. For the proposed system, four parameters were studied, which were the pressure drop over the flow bath, the water productivity per square metre as the goal parameter and the influence of ambient temperature as well as humidity. The ambient conditions were considered as the design parameters. The three different climatic regions are Red Sea, Arabic Gulf, and southern Europe (south Spain). Only summer climatic conditions are considered. It is found that the pumping power required for air fan did not exceed 9.1 W. Fresh water productivity of the unit was up to 3.9 L/h/m².     

Risk‐based water resources planning in practice: a blueprint for the water industry in England

Resilient water supplies in England need to be secured in the face of challenges of population growth, climate change and environmental sustainability. We propose a blueprint for water resources planning that uses system simulation modelling to estimate the frequency, duration and severity of water shortages at present and in the context of future plans and scenarios. We use multiobjective optimisation tools to explore trade‐offs between these risk metrics and cost of alternative plans, and we use sensitivity analysis to identify plans that robustly achieve targets for tolerable risk, alongside other performance objectives. The results of a case study in the Thames basin demonstrate that the proposed methodology is feasible given commonly available data sets and models. The proposed method provides evidence with which to develop water resource management plans that demonstrably balance the risks of water shortages, costs to water users and environmental constraints in an uncertain future.     

Predicting and quantifying the effect of variations in long-term water demand on micro-hydropower energy recovery in water supply networks

To improve water supply energy efficiency micro-hydropower turbines can be installed within networks at locations of excess pressure. However, future changes in flow rates and pressures at these locations could render an installed turbine unsuitable. It is therefore important that long term changes in flow conditions at potential turbine locations be considered at initial feasibility/design stages.

Using historical data over a ten-year period, this paper predicts the effects of changes in water flow rates at potential turbine locations in Ireland and the UK. Results show that future flow rates at these locations could be predicted with an R² of up to 66% using multivariate linear regression and up to 93% using artificial neural networks. Flow rates were shown to vary with population, economic activity and climate factors. Changes in flow rate were shown to have a significant impact on power output within the design life of a typical hydropower turbine.     

Optimization of alum recovery from water treatment sludge‐case study: Samannoud water treatment plant,Egypt

Alum recovery from water treatment sludge is a promising technique applied for reducing the virgin coagulant demand and the sludge volume and safe disposal of the sludge. The aim of the current study is to optimize alum recovery process from alum sludge in Samannoud water treatment plant, Egypt by acidification technique using sulphuric acid and evaluate the effect of total solids (TS) content in the sludge on alum recovery process. Results showed that the optimal mixing time for alum recovery was 60 min for clariflocculator sludge, whereas 15 min for thickener sludge. Optimum pH value was 1.50 for alum recovery from different sludge types. At optimum conditions, acidification experiments showed that alum recovery percent and sludge volume reduction for clariflocculator sludge were 83 and 91.2%, respectively, versus 35.9 and 45%, respectively, for thickener sludge. Besides, alum recovery and sludge reduction decreased with the increase in TS content in the sludge.     

Effects of run‐of‐the‐river hydropower plants on the surface water quality in the Solakli stream watershed,Northeastern Turkey

In recent years, Turkey has turned its attention to alternative energy sources rather than fossil fuels. The Eastern Black Sea Region of Turkey has steep mountains with hilly topography and has large potential in terms of energy production with run‐of‐the‐river hydropower plants (RHPPs). In this study, the effects of two RHPPs on some water quality parameters were examined in the Solakl? stream watershed. This research was conducted over the course of 12 months (January–December 2014). In total, 12 sampling points were selected and various water quality parameters, such as temperature, pH, dissolved oxygen, total suspended solids, electrical conductivity, total dissolved solid, chloride and salinity, were monitered at each point. Statistically, significant changes occured in water quality parameters such as total suspended solids, pH and temperature. In particular, total suspended solids ranged from 10 to 440 mg/L.These results suggest that the RHPP negatively effect water quality and quantity in the main stream in both the operational and constructional phases.     

南楼水厂送水泵站节能改造实践

针对南楼水厂送水泵站水泵运行工况偏离高效区的问题,通过技术分析和科学论证,采用更换高效率水泵、切削水泵叶轮等方法对泵站实施节能改造。运行结果表明,该送水泵站节能改造投入资金少、风险小,实施后水泵机组效率明显提高,节能效果和经济效益显著。     

酒店蒸汽冷凝水再利用节能分析

酒店蒸汽冷凝水回收是十分必要的，这对于节能、节水及环境保护都有重要的意义。在凝结水回收系统的选择时，应根据实际情况做经济技术比较。通过对不同系统特点及工程实际运行经验的分析，认为闭式回收系统应优先被考虑和采用，其中冷凝水回收器回收系统是一种理想的回收方式。     

Sustainable water use and the nexus of behavioural intentions: the case of four South African communities

South Africa continues to ramp up public campaigns to rein in escalating water demand against the backdrop of dwindling and erratic supply. While the water conservation campaign appears to resonate with commercial and urban water users, it does not seem to have gained traction with rural and periurban residents. Using the sequential mixed methods, this paper explores the water conservation attitudes, behaviour and intentions of rural and periurban respondents in four South African communities. Results reveal respondents consider water conservation important and are favourably disposed to conserving water. Attitude, subjective norm and behavioural control emerged as significant factors influencing respondents’ water conservation intentions. The study concludes that rural and periurban residents are yet to develop a social ethic of water conservation essential in creating sustainability of resource use.     

Empirical evaluation of river basin sustainability affected by inter‐basin water transfer using composite indicators

In this study, a practical approach to evaluate the sustainability of river basins subjected to an inter‐basin water transfer project is developed. Selection of appropriate evaluation indicators is pivotal to such approach. To make use of huge amount of data, composite indicators of sustainability (CIS) should be utilised. The proposed approach relies on 15 sustainability indicators (SI) that cover three major criteria namely (economic, social and environmental), and aggregates them into eight different types of sustainability indices for a more robust outcome. Two scenarios were considered within the source and recipient basins. Furthermore, multivariate principal component analysis (PCA) was applied to determine principal and non‐principal indicators for the two river basins. The ability of CIS and PCA methods were verified via correlation and simple regression methods respectively. The results demonstrated that inter‐basin water transfer may improve sustainability, provided that a proper water resource management is enforced.     

Economic implications of water efficiency measures I: assessment methodology and cost-effectiveness of micro-components

Economic efficiency has recently become one of the primary objectives of water management decisions. In particular, as vulnerability of freshwater systems has become evident and there is a trend for water supply managers to look towards water demand management, identifying the cost of such measures is becoming increasingly important. In England and Wales, Part G of the Building Regulations requires that water consumption of a new dwelling should not be more than 125 litres/capita.day. However, while compliance with this is determined by the water use characteristics of the installed micro-components (WCs, showers, basin taps, kitchen taps, baths, dishwashers and washing machines), the cost to consumers resulting from installing water efficient micro-components is not clear. This paper evaluates the potential economic implications of water saving micro-components, assessed from the consumers’ perspective. A methodology has been developed and implemented to assess the cost-effectiveness of several types of water efficient micro-components. A range of cost assessment methods was applied, and critically reviewed comparing their outcomes. It was found that conventional cost assessment methods are unsuitable for identifying the least cost options to consumers. Of the applied methods, the modified annualised assessment method appears to be a relatively better option.     

采掘业水资源论证若干问题探讨

通过工程实践,总结了建设项目水资源论证报告书编制过程中存在的问题,并针对存在的问题提出了解决问题的建议,对促进水资源的高效利用和有效保护具有极其重要的意义。     

小型空调器冷凝热回收技术的研究现状与应用分析

分析了回收空调冷凝热用于室内生活热水供应的可行性.在大型空调系统冷凝热回收技术成功运用的基础上,回顾了国内外小型空调器冷凝热回收的研究现状,认为现有系统产品化还需要一段较长的研究过程.针对我国在这方面的研究状况,指出了几个研究方向.最后,提出了一种能在我国应用的改进系统,介绍了系统的基本原理及研究现状,指出了该系统产品化还需要进一步解决的若干问题.     

冷凝热回收系统中的热水系统设计探讨

结合一座典型星级酒店,提出了一套应用冷凝热回收的热水系统设计方案,并通过对补水方式、运行工况等内容的优化设计进一步降低能耗。     

Assessing the marginal cost of reducing greenhouse gas emissions in the English and Welsh water and sewerage industry: A parametric approach

Reducing greenhouse gas (GHG) emissions involves effort from different sectors of the economy, including the water and sewerage industry. This study estimates the marginal cost of curtailing GHG emissions in the water and sewerage industry using stochastic frontier analysis techniques for a sample of ten English and Welsh water and sewerage companies over the 2010–2019 period. Results illustrated that the average marginal cost of reducing GHG emissions was 0.181 £/Kg CO₂ equivalent. The marginal cost estimated notably differs across companies and over time. Findings further illustrate the impact of water companies' operating characteristics on the marginal cost of reducing carbon emissions.     

Modelling the urban water chain: Incentives and cost recovery in wastewater treatment in developing countries

To improve surface water quality in developing countries new approaches to design wastewater treatment schemes have been developed. We identify a compliance problem in these schemes which threatens their success. To analyze this problem, we integrate a compliance game into a model of the urban water chain. We illustrate the model with a numerical example on small scale leather processing. We find that the compliance problem indeed threatens the overall success of the treatment scheme and show under which conditions this is so. With an empirical calibration our model is a ready to use tool to provide quantitative results that can inform planners of urban wastewater treatment schemes.