]. These approaches help reduce the volume of water imported to cities, and in some configurations can also reduce the volumes of wastewater and stormwater discharged into the environment . On the other hand, the use of these systems may have some detrimental impacts on the centralized water infrastructure, particularly on the sewage network and stormwater drains. The use of decentralized water supply systems changes both the wastewater and stormwater flow regimes and contaminants’ composition [16–18]. For instance, as water saving and recycling are encouraged through grey water reuse, dual piping systems, and sewer mining, the quantity of wastewater may decrease leading to an increase in its concentration of contaminants . High-concentration wastewater has been known to cause sewer problems such as sewer blockage, odor and corrosion . Thus, to ensure the smooth and effective implementation of hybrid water supply systems, it is necessary to evaluate their impacts on the existing wastewater and stormwater system. Such an evaluation requires a comprehensive methodology to enable the evaluation of various subsystems and their interactions to contribute to the overall performance of hybrid systems [4,21].
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Abstract. Water supply systems (WSSs) are vital infrastructures for the well-being of people today. To achieve good customer satisfaction the water supply service must always be able to meet people’s needs, in terms of both quantity and quality. But unpredictable extreme conditions can cause severe damage to WSSs and lead to poorer levels of service or even to their failure. Operators dealing with a system’s day-to-day op- eration know that events like burst water mains can compromise the functioning of all or part of a system. To increase a system’s reliability, therefore, designs should take into account operating conditions other than nor- mal ones. Recent approaches based on robust optimization can be used to solve optimization problems which involve uncertainty and can find designs which are able to cope with a range of operating conditions. This paper presents a robust optimization model for the optimal design of water supply systems operating under di ff erent circumstances. The model presented here uses a hydraulic simulator linked to an optimizer based on a simulated annealing heuristic. The results show that robustness can be included in several ways for varying levels reliability and that it leads to more reliable designs for only small cost increases.
The amount of water available for withdrawal is a function of runoff, groundwater recharge, aquifer conditions, water quality and water supply infrastructure. Safe access to drinking water depends more on the level of water supply infrastructure than on the quantity of available runoff. However, the goal of improved safe access to drinking water will be harder to achieve in regions where runoff and/or groundwater recharge decreases as a result of climate change. In addition, climate change leads to additional costs for the water supply sector, which might hamper the extension of water supply services to more people. This leads, in turn, to higher socio-economic impacts and follow-up costs, especially in areas where the prevalence of water stress has also increased as a result of climate change (Bates, Kundzewicz, Wu, & Palutikof, 2008). In this context, the concept of correct management of water supply systems includes the ability to organize a distribution system capable to ensure proper supply of the resource, even in relation to changes in demand or water availability. Therefore, appropriate optimization strategies are necessary, and the proper allocation of available resources is becoming increasingly important in order to achieve an optimal management of such type of systems. For these systems the goal of achieving the lowest water usage rate is of interest not only in relation to operating costs and economic management optimization, but also in relation to financial optimization of investment plans. In fact, the optimization of new pipelines has a positive impact on water tariffs. With the aim of proper management of investment plans, there is a need for fast and accurate methodological forecasting tools for water supply systems optimization which are capable of accounting for possible future scenarios of reduction in water availability due to the effects, e.g., of climate change or evolution of demand. In this paper an optimization solution accounting for the expected reduced availability of water resources in the context of climate change was created and compared with the optimization solution for current water availability.
Supplying clean and safe drinking water evenly to residents is the basic responsibility of the national water management policy to realize water welfare in any country. This study investigated 1,526 samples of small water supply systems in 12 cities and counties in Chungcheongnam-do Province, South Korea to come up with measures to improve water quality and operation management of small water supply systems, a major source of water in rural areas. The results revealed that in total, 1,183 samples (77.5%) out of 1,526 samples supplied in 12 cities and counties were suitable for the current drinking water standard of Korea. However, 343 samples (22.5%) were found to be inadequate for water quality. The main non-conformities item of water quality in the facilities were found to be 34.1% of microorganisms; general bacteria, total coliforms, due to some characteristics of the rural area, 17.2% of nitrate caused by a livestock and excrement facilities, 7.9% of fluorine and 5.5% of turbidity, and 2 items or more redundant facilities were found to be 18.7% of unsuitable samples. This indicates that geological strata, facility management insufficiency, and poor disinfection control conditions in areas where small water supply systems are installed are the main factors in determining the quality of water. By doing this, we intend to enhance the effectiveness of the sustainable water management policy for the realization of equal water welfare in the country and provide important ideas for the fundamental improvement and operation management of small water supply systems currently operating in rural areas.
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Mass migration to cities, availability of high yielding water extraction technologies, and lack of funding to maintain the existing Qanats have resulted in the decline of the share of Qanats in supply of water to rural com- munities in many Middle-Eastern countries. The cli- matic change and its impact on regional water resources have also led to decline of water tables (Yin 2003). This resulted in overexploitation of groundwater resources due to excessive issuance of permits for deep wells and caused many Qanats to dry up. As such, the community distribution of water rights that has been provided and protected by Qanats over many centuries is now being replaced by demands, from individual farmers, for deep well permits. This has led to growing inefficiencies in irri- gation water uses in a region affected by severe droughts and water scarcity.
Abstract: In the domestic water supply industry, the reduction of pumping costs is a continuing objective. With the efficient scheduling of pumping operations, it is considered that 10% of the annual expenditure on energy and related costs may be saved. A typical cost function will include all of the expenditure caused by the pumping process and also consider the electrical cost of pumping taking into account the various electrical tariffs, as well as peak demand and pump switching costs. Using only fixed speed pumps, it is possible to use an efficient dynamic programming based method, provided that the storage reservoir levels are known. Other techniques that are showing fruitful results in optimisation are genetic programming and simulated annealing. This paper compares these methods and discusses which is more appropriate in this type of pump scheduling problem.
The objective of these case studies is to provide information on the performance of projects and the used project approach from Plan. As it appears from literature study, the used project approach is proved to have a direct influence on sustainability. That’s why many authors measure the used project approach and the performance in one framework. This framework provides all information to compare different projects, but also creates unproved relations between sustainability and project approach. That’s why for the purpose of this research two frameworks of indicators will be defined, one for the performance and one for the project approach. This allows drawing separate conclusions first, which can be linked together in a later stage. Both frameworks are applied to two case studies to be chosen. The research framework with all the indicators and sub-indicators is written down in Annex C. The different questions to be asked for the assessment of each sub-indicator are for the assessment expressed as sub-sub-indicators. The two case studies should provide enough information on the performance of the system to draw conclusions on the sustainability of gravity water systems in general, on the condition that the systems are implemented some years ago. It is more difficult to draw conclusions on the project approach. The first issue is that a ‘sustainable project approach’ can never guarantee sustainability, because external factors are also influencing this. In the second place a variety of assumptions exist about a ‘sustainable project approach’. Thirdly Plan Cameroon is always changing their project approach. This makes information from projects carried out years ago outdated. This leads to the following strategy:
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performance and identify operational strategies for improving water supply systems in Nigeria. Water has remained the most crucial element in the environment as mankind significantly depends on it for their existence. Performance metrics framework for productivity of water supply system (WSS) in Nigeria has thus far been underestimated hence the need for user friendly approach to effectively assess critical activities of the system. A re- engineered productivity award model (RPAM) adopted in this study consists of 10-point core measures that control overall performance of the WSS as well as other supportive measures for the realization of set goals of the system. The application of the model recorded a score of 44.08% which is an inducement to placing WSS on the threshold of significant achievement of strategic goals. This suggests possible adaptation of the model and improvement effort which has the capacity of addressing identified barriers to its implementation. The capacities of the strategic adaptive framework include creation of competitive platform for recognizing stakeholders who have greater influence in higher productivity solutions in water supply systems.
Abstract - This paper presents the necessitate and value, and also conception of water supply systems which flows in flexibly and can deliver water with flexibility in occurrence rate, and duration beneath the control of the farmer at the specific relevance using a partial rate stipulate or other schedule."Obstruction"-Total capacity and reserve time is essential to pledge water delivery at the specific frequency and desired rate as well as it introduces the needed expressions. It emphasizes the conversion of the economical steady deliver canal flows flexibly on-farm convention throughout the usage of service area reservoirs located between the secondary and tertiary systems. Partially closed pipelines and level-top canals as automatic distribution systems which tries the farmers the requirement for daytime as well as at night . Probably on-farm deliveries it used to permit optimization of on-farm water management. This enhanced management which be the ultimate source of augmented food production after improving land, and water resources, crops and reached to their maximum level. This is preferable for farmer’s and will save their lots of time and increased their work level without any uncertainty.
Since such simple application of a certain percentage of hot water usage or hot water usage ratio in summer compared to winter without taking into account scale of hot water usage round the year or usage pattern by season would cause some economical difference compared to the actual usage of hot water, it would be necessary to conduct researches which would present thermal load sharing ratios for economical optimal-sized solar-powered hot water supply systems tak- ing into account the hot water usage by actual building type. In this context, this study would present a method of esti- mating optimal thermal load sharing ratios for solar- powered hot water supply systems by considering economi- cal scale and efficiency of facilities when applying solar- powered hot water supply systems based on the analysis of usage pattern of hot water facilities by building type through case study of hot water us-
ten equal groups and from each group, a total of three households were randomly picked to give a sample size of thirty households from each village. In each household, the household head was the targeted respondent, but in instances where the household heads were not immediately available, other adult members of the household were used as proxies and interviewed. In situations where any household member volunteered information during the survey, such information was promptly recorded. The survey sought to establish, among other things, the water uses in the community and their respective water quantities. This was done to estimate the current community water demand which was then compared against the demand the water supply systems were originally designed for. If the quantity of water from the SAS was adequate to entirely meet the community’s daily water requirements, then this contributed to the evaluation of the SAS as a sufficient rural water supply option. Another objective of the survey was to establish the most preferred water source by the communities among the water supply sources in the study area. In this regard, the villagers were asked their perceptions of the SAS in comparison with other common water sources within the study area. The villagers were also asked about the constraints associated with the SASs.
This article discusses the main stages and features of wastewater treatment at “Food Ingredients” LLC (Russia, Krasnodar region) involved in vegetable oils and fats refining. The experimental data on averaged qualitative com- position of industrial wastewater involving the period from January to June, 2018 were presented. The indicators of the quality of averaged waste did not exceed: 20 mg/l for ammonium nitrogen; 20 mg/l for phosphates; 800 mg/l for suspended solids; 700 mg/l for fatty substances. The operation of biological aeration tank was analyzed from January to June, 2018. The graphic dependences of the change of sludge index, phosphate ions, chemical oxygen demand (COD), and temperature were given. The species composition of microorganisms and their amount were determined by means of optical microscopy. Absolute quantity of microorganisms in activated sludge was deter- mined with the “calibrated droplet” method. As of October 31, 2018 the quantity of microorganisms was as fol- lows, U/ml: small flagellates – 44,015; free swimming infusoria – 34,233; Euglypha – 6,520; Vorticella – 27,713; Rotatoria – 29,343; Aspidiska – 36,950; Aelosoma – 2,173; Heliozoa – 1,086. No filamentous microorganisms were detected. After treatment, the recovered water was characterized by the following indicators of the quality: transparent, ammonium nitrogen content in water was less than 0.1 mg/l, phosphate ion content was no higher than 0.2 mg/l; COD was no higher than 30 mg O 2 /l, hydrogen index was about pH = 7. These indicators comply with the requirements for water in technical water supply systems of industrial enterprises (Russia), as applied to recovered water produced of wastewater for subsequent use in recycled water supply system. The treated water is reused in the production processes, which evidences high quality of water treatment and reliable operation of the equipment in local treatment facilities at “Food Ingredients” LLC during 10 years of operation.
Abstract: - Over the last few decades water stress has been increasing both due to an increase in water demand and reduced water supply. Water leakage reduction in public water systems is a crucial part of water demand management. Leakage is usually the largest component of distribution loss yet it is not subject to regulation other than management decision by utilities. Leakage in public water supply systems results in loss of purified drinking water but also means wasting the energy and material resources used in abstraction, transportation and treatment. It results in secondary economic loss as well, in the form of, damage to the pipe network, public health concerns as it increases the risk of bacterial contamination of water resources in cities for human consumption, and can increase pollution loads into the environment. Leaks in pipe networks can result for several situations. A water operator must have an understanding of the causes of leaks so that they can be both repaired and prevented in the future.
There were 5 types of possible dangerous events to occur, in which the first one evaluated was the water leakage from the distribution pipelines. For Fontana (2015), this event is one of the main challenges for water supply managers, since it is capable of causing the reduction of the flow due to the decrease of the volume of water drained from the exhaust. Even though it was classified as low risk in this study, for Ramos et al. (2001) apud Fontana (2015) to search for solutions that try to minimize this type of problem is necessary, because due to the occurrence of leaks in the network, besides generating the decrease of the available water, it can happen to the interruption during the maintenance of the ducing users' dissatisfaction. For this type of event, according to the authors, the adoption of a loss management strategy would be a viable option for the control of this type of occurrence.
Access to safe water supply has great influence on the health, economic productivity and quality of life of the people. But meeting this need is one of the major challenges facing the rural communities of Nigeria today. The purpose of this review paper is to determine whether water supply have contributed effectively to health, social, and cultural development of Nigerian rural communities. Over 70% of households in rural communi- ties do not have access to improved water supply. They rely solely on self-water supply (free source) such as rivers, perennial streams, water ponds and unprotected wells which is susceptible to water borne diseases such as typhoid fever, cholera, dysentery, malaria parasites etc. These rural populations are engaged in farming activities with low income level living in small scattered settlements thus, making provision of piped water supply very difficult. Governments’ interventions towards rural water supply have been through the provision of hand-operated boreholes and wells. These sources yield little or no water during the dry season and are prone to frequent breakdown; leading water crisis and shortages. This situation forces households especially the women and children to spend more time walking longer distances during the dry season to trot water for domestic purposes. Given the fact that the publicly operated water supply have not been able to cope with increasing demand, there is a need for a paradigm shift from the public monopoly of water supply to an innovative approach. Rainwater harvesting technology appears to be one of such alternative ap- proaches.
Diseases stemming from contaminated water aren’t the only problem plaguing the society. In a household where money is scarce and women (mothers and daughters) have to spend several hours each day walking to get water from pumps, they are at risk of being attacked or raped. TGNP, Tanzanian Gender Networking Program, has researched in a study of poor households “that the lack of safe, sufficient, and affordable water in Tanzania had increased rates of gender-based vio- lence and the number of girls dropping out of school.” Families who don’t have money for water, let alone school, have no choice but to send their daughters out to collect water, possibly resulting in these episodes of violence. Unfortunately, the choices of these families are limited, they need water to survive. (Mbilinyi & Shechambo, 2009)
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Going forward, we expect that large, multicenter, global studies will be needed to obtain a more comprehensive picture of intracranial aneurysm hemodynamic pathophysiology and to develop more reliable risk-prediction models. This effort will likely require better classification of aneurysms (eg, based on an- eurysm size, location, phenotype, perienvironment, and patient population), rather than treating them as a conglomeration. Dif- ferent predictive models could be extracted from different classes of datasets and applied to intracranial aneurysms that belong to specific categories. For example, statistical analyses of small aneu- rysms may produce a different set of predictive parameters (re- lated to high WSS and a positive WSS gradient) from that of large aneurysms (related to low WSS and a high oscillatory shear in- dex). We envision that intracranial aneurysm cases could be carefully classified and then subjected to the appropriate pre- dictive models. The models should reflect the underlying mechanisms driving aneurysm growth and rupture. As such, intracranial aneurysm classification based on size alone may not be highly accurate. An alternative strategy would be to identify type I and II aneurysms from imaging and then to perform subgroup risk analyses and management.
Interestingly, there was no significant correlation between total ODA per capita received by a country and any of the child health indicators. There was however a significant association between higher levels of increase in sanitation and reductions in infant and child mortal- ity, with adjusted odds ratios of 8 and 9 times for the highest compared to the lowest tertiles, respectively. It is unknown why there is an apparent lack of association between this relationship and WSS-ODA. It may be due to ineffectiveness in investments, a weak capacity of the mandated national institutions, or perhaps due to suc- cess on behalf of local, non-internationally funded efforts. The higher odds of sanitation, as compared to water access, producing significant reductions in child mortality is consistent with the literature including a study by Fewtrell and co-workers [29-31], who showed that sanitation and hygiene have a greater impact in relative risk of acquiring diarrhea compared to water quality and water supply projects. And yet, at least for donors that do provide disaggregated WSS-ODA data, only 30% of funding goes to sanitation and hygiene
Biophysical accounting for hydrological ecosystem ser- vices allows for the organization and analysis of biophysical data on these services at different spatial and temporal scales suitable for the development, monitoring and evaluation of public policy (EC et al., 2013). Biophysical accounting also allows for the distinction between the flow of hydrological ecosystem services and the capacity of watershed ecosys- tems to provide service flows (EC et al., 2013). Service flow is the contribution in space and time of an ecosystem to ei- ther a utility function (e.g. private household) or a production function (e.g. crop production) that leads to a human benefit, whereas service capacity is a reflection of ecosystem condi- tion and extent at a point in time, and the resulting potential to provide service flows (EC et al., 2013; Edens and Hein, 2013). For hydrological ecosystem services, high service ca- pacity areas and high service flow areas may occur in dif- ferent points or areas in space (Fisher et al., 2009), making the need for their empirical distinction and separate spatial characterization crucial for land and watershed management. Many approaches have been used for modelling, map- ping and quantifying hydrological ecosystem services (e.g. Le Maitre et al., 2007; Naidoo et al., 2008; Liquete et al., 2011; Maes et al., 2012; Notter et al., 2012; Willaarts et al., 2012; Leh et al., 2013; Liu et al., 2013; Terrado et al., 2014, for an overview). For ecosystem accounting, how- ever, key aspects requiring further research include the mod- elling of hydrological ecosystem services with adequate spa- tiotemporal detail and accuracy at aggregated scales, distin- guishing between service capacity and service flow, and link- ing ecohydrological processes (and ecosystem components) to the supply of dependent hydrological ecosystem services. Addressing these issues requires the consideration of among others physical and mathematical representation of ecohy- drological processes, spatial heterogeneity of ecosystems, temporal resolution, and required model accuracy (Guswa et al., 2014). Adequate representation of the spatial heterogene- ity of biophysical environments in ecohydrological models is crucial in ecosystem accounting because spatial units form the basic focus of measurement similar to functions of eco- nomic units in national accounting (EC et al., 2013). In addi- tion, if ecosystem accounting is to provide reliable informa- tion for the assessment of integrated policy responses at the
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A model of a BSWH solar water heating system was fabricated and tested. The purpose of this project was to develop a low cost solar water heater. Specifically a BSWH solar water heater constructed from home-grown materials and labor that would cost less than 2500 INR and deliver 30L of 60°C water by 5:00pm. Based on these measures, a batch, integrated storage-collector system was selected. Materials were selected based on cost, performance, and accessibility in Jaipur (Rajasthan).