Domestic Water Supply Research Articles

Investigation on the thermal performance and economy of a solar assisted air source heat pump domestic hot water system

In order to increase the utilization of renewable energy and reduce carbon dioxide emissions, a solar assisted - air source heat pump (SA-ASHP) domestic hot water supply system is proposed, designed and built, the thermal performance and economy are numerically simulated and experimentally verified, the optimal design parameters are determined based on the economic optimization analysis. The results show that the coefficient of performance (COP) of air source heat pump (ASHP) varies from 2.62 to 3.93 and the COP of SA-ASHP system varies from 2.76 to 6.26. The solar fraction varies from 8.83% to 45.51%, and varies greatly in different seasons. The simulated heat collection of solar collector, the power consumption and heating capacity of ASHP, and the total power consumption of water pump are in good agreement with the measured results. Compared with the existing SA-ASHP system, the annual cost has decreased by 1998.32USD, annual cost converted from initial investment has decreased by 629.08USD, operating cost has decreased by 1369.25USD and total power consumption has decreased by 16897.79 kWh of the optimized SA-ASHP system. The optimum ratio between the input power of ASHP and the collector area is 0.078 kW/m2. The research results play an important role in guiding the design, operation and heat source selection of domestic hot water (DHW) system in student dormitory.

Groundwater quality and its implications for domestic and agricultural water supplies in a semi-arid river basin of Niger

Groundwater quality and its implications for domestic and agricultural water supplies in a semi-arid river basin of Niger

A Study on the Hydropower Energy Generation by Utilizing Domestic Water Supply

Majority of households around the globe are connected to primary water supply grids that supply water for domestic use throughout the year. In many instances, the companies supplying water to these households maintain header pressure between the maximum and minimum as a guarantee for the water to reach the consumers. This paper is, therefore, aimed at investigating the potential of this pressure in driving turbines for power generation so that the energy could be stored in rechargeable batteries which can be utilized whenever needed. Two sets of experimental setups were developed with turbines arranged both in series and parallel. The experiments were conducted using three working pressures, such as 1.5, 3.2 and 5 bar. It was observed that the turbine mainly depends on the water flow rate, where the higher flow rate is achieved in working pressure of 5 bar which is 33 LPM and 6 Watt generated. The power produced was increased to 12 W with a slight pressure drop of 0.1 bar after the second turbine. However, the drop in pressure was observed to be slightly higher for the lower working pressure. The turbine cut-off pressure was 0.4 bar. Moreover, it was also evidenced that arranging the turbines in parallel has also resulted in an enhanced power generation.

Rainwater Harvesting as Sustainable Solution to Cope with Drinking Water Scarcity and Urban Flooding: A Case Study of Public Institutions in Lahore, Pakistan

Pakistan is currently facing physical and economic water scarcity issues, which have been further complicated by the rapid increase in its population and climate change. In affected areas, many methods are being used to tackle this problem, among which rainwater harvesting (RWH) provides the best alternative source of domestic water supply. In rainwater harvesting, a mechanism is designed to effectively collect surface runoff during rainfall events from residential rooftops. It has also been found that rainwater has great potential as a source of water supply in residential areas of major cities, such as Lahore, which is the focus of our study. This research paper examines rainwater harvesting as a sustainable solution to address the challenges of drinking water scarcity and urban flooding. The study discusses the benefits of rainwater harvesting, including reducing reliance on municipal water sources, improving water quality, and mitigating the impact of urban flooding. Additionally, the paper explores the use of filtered water points in conjunction with rainwater harvesting systems to provide clean drinking water to communities. The research draws on case studies from various regions to illustrate the effectiveness of rainwater harvesting as a sustainable solution to water scarcity and urban flooding. Ultimately, the study concludes that rainwater harvesting, when coupled with filtered water points, can offer an effective and sustainable solution to address drinking water scarcity and urban flooding.

A tug of war between centralization and decentralization: the co-evolution of urban governance and water risks in Guwahati, India

Intermediate cities in Asia and Africa house more than 60% of the world’s urban population. More than 54% of the people here face high levels of water stress and are increasingly vulnerable to water-related risks such as floods, limited access to safe drinking water and water pollution. These urban water risks are complex outcomes of climate change, land use changes, governance failures, and social inequities. This study examines the co-evolution of three water risks and governance responses through the case of Guwahati, India. Guwahati, on the Brahmaputra River in the Northeast of India, serves as a case of an intermediate city to demonstrate changes in water risk governance trends. We focus on studying the connected governance responses to changes in three interrelated water risks, i.e., domestic water supply, urban floods, and river pollution. The shifts in the socio-political structures for these risks are assessed by combining historical institutionalism with multi-level perspective theory. The results show that despite the growing diversity of actors and devolution of responsibilities in cities to mitigate water risks, there is an ongoing tug-of-war between centralized and decentralized modes of decision-making. Contrary to the recommendations for decentralized urban governance, the trend is currently tugging towards a centralized decision-making mode. However, when differences arise between the local and national, local actors within their limited frames of action manage to circumnavigate nationally dictated mandates to fit local needs.

Step-by-Step Fabrication of PVDF-TiO2 Hollow Fiber Membrane and Its Application Desalination of Wetland Saline Water via Pervaporation

Wetland water is opted as the source of domestic water supply when the availability of clean fresh water is scarce. Wetland water requires proper treatment due to the high concentration of organic matter and high salinity, particularly in the dry season. This research aims to synthesize, characterize, and investigate the performance of polyvinylidene fluoride (PVDF)-TiO2 hollow fiber membrane for wetland saline water desalination via pervaporation. The PVDF-TiO2 hollow fiber membranes were fabricated through the dry wet spinning method under various air gaps (10, 15, and 20 cm). Then, the resulting membranes were tested in a pervaporation process at temperatures of 25, 40, and 60°C. Results show that the incorporation of TiO2 into the PVDF matrix imparted hydrophilicity properties into the resultant membranes. The presence of TiO2 was confirmed by the TiO2 stretching vibration at 1640 cm-1 (FTIR) and the TiO2 phase at diffraction peaks at 25.5 and 37°. The membranes exhibited the highest water flux (7.48 kg/m2.h) and salt rejection ( 99.5%) at 40°C. Overall, the developed PVDF-TiO2 hollow fiber membranes showed encouraging results and demonstrated their effectiveness for the desalination of wetland saline water.

Development of Hydraulic Ram Pump for Agriculture Uses and Approach A Review

Abstract: This report focuses on Hydraulic Ramp Pumps that have been used worldwide for over two centuries in many areas. The project idea is to build a pump known as Hydraulic Ram Pump [HRP] that gets the water higher level, Kinetic Energy at the inlet, and converted it into pressure energy. This is commercially successful because of its simplicity and reliability. The hydraulic ram pump (hydram) is a viable and appropriate renewable energy water pumping technique developed in many countries, our project team can get the idea to design and manufacture a more efficient and long time durable Hydraulic Ram Pump so that it can solve major problems by providing adequate domestic water supply to Rural Populations and Agricultural Land, it is difficult to the water served by a conventional pipe system.

Practices and Barriers of Water Use Efficiency in the Federal Capital Territory, Abuja, Nigeria

The fast rate of population growth and increased urbanisation has exacerbated the domestic water supply problem in the Federal Capital Territory, Abuja; Nigeria. This study examines water use efficiency practices and the barriers inhibiting it among residents of the Federal Capital Territory, Abuja, Nigeria using appropriated standard techniques. Data obtained shows that about 70% of respondents say they turn off the public tap whenever they see water dripping from them unattended, more than 50% admit to being agents advocating water use efficiency in their communities and more than 40% consider water-saving appliances when they make purchases of domestic appliances. The inhibitors to water- use efficiency in the study area, include a poor grasp of sustainability principles and cultural beliefs that promotes the idea of inexhaustible water resources; lifestyles that do not promote water use efficiency; and the inclination to only use water efficiently when it in short supply or when the price of water rises. Residents of the Federal Capital Territory should be made to understand their roles in efficient use of water and embrace sustainable water use.

მინიმალური ხარჯების შედარებითი ანალიზი ეკოლოგიური ხარჯის განსაზღვრისათვის მდ. ალაზნის (შაქრიანი); მტკვრისა (ხერთვისი) და ფარავნის (ხერთვისი) მაგალითზე

Minimal runoff plays a crucial role in designing industrial and domestic water supply, to determine minimal discharge of water in rivers observation data of winter and summer-autumn seasons are used. There are selected the stations of rivers which have the longest observed data series. These rivers are Alazani (H/S shakriani), river Mtkvari (H/S Khertvisi), river Paravani (H/S Khertvisi). As a result of actual observed data of minimum discharges were allocated to the research rivers, such as: · 30-day minimum discharge (non-calendar year) · Instantaneous minimum discharge · Minimum discharge taken from daily average data. Nowadays, in Georgia there is no legal basis and corresponding normative-technical documentation for determining the normative values of discharge of water discharged for ecological purposes which of course is the cause of numerous problems in terms of conservation and use of water resources. Therefore, it is crucially important to take into consideration the complex relationship between minimum and environmental flows.

Domestic practices for accessing water and rural-urban transformations: example of emerging urban centres in Tanzania

ABSTRACT The transition from rural to urban spurred by population growth and housing densification has implications for the planning of service provisions, not least domestic water supplies. The objective of this paper is to document the status of domestic water access and examine existing options for domestic water provision along the rural–urban transition. The study employs a combination of research methods in both data collection and analysis. Given the dual character (rural–urban) of the emerging urban centres, there is limited distinction in the domestic water services provided since they tend to be in between the two, in a state of transition.

Improvement of WEAP model considering regional and industrial water distribution priority and its application

Study regionGuangdong-Hong Kong-Macao Greater Bay Area urban agglomeration (GBA). Study focusExisting Water Evaluation and Planning System (WEAP) lacks consideration of regional and industrial water distribution priority. This study proposes an improved WEAP model by integrating regional and industrial water distribution priority determined by water supply safety. The logistic curve model was introduced for water supply safety evaluation. The improved WEAP model was applied to the water resources allocation of GBA in the year of 2019 and 2030, and the effects of water allocation schemes with different regional and industrial water distribution priorities were compared. New hydrological insights of the regionThe results indicate that the water supply safety of each city in the GBA varies with region and industry, Guangzhou, Shenzhen and Dongguan have lower degree of domestic and industrial water supply safety. River and reservoir connections are essential to the water supply safety of GBA. The water demands of Shenzhen and Dongguan cannot be satisfied during dry period in 2019, while perfectly satisfied during the dry period in 2030 due to the operation of water transfer projects. The improved WEAP model obtained more reasonable water allocation results, improving the water satisfaction rates of regions with low water supply safety. The research demonstrates the advantage of the improved WEAP model considering regional and industries priority, enhancing the applicability of the WEAP model.

The cost of domestic water provision in Morogoro Municipality, Tanzania

Accessible water is a basic human right but due to its fugitiveness and paucity, water is an economic good, rather than a public one. A reduced supply of water causes high financial and social costs. This study examined using the cost-based approach, the value of Mindu Dam by providing public water to Morogoro Municipality in Tanzania. It focused on the cost of water treatment and of constructing boreholes to ensure an efficient water supply. Data were collected from Morogoro Water Supply and Sanitation Authority (MORUWASA), the Wami/Ruvu Basin Water Board (WRBWB) Office, and three wards of the municipality. Household data were analyzed by descriptive techniques that involved computation of proportions, and valuation data by cost-based approaches. Due to pollution and degradation of the Mindu Dam, the municipality loses about 1,168,756,011 TZS (24,145.22 USD) per year for water treatment while the dam capacity decreases progressively. By using the boreholes alternative, the value of Mindu Dam by providing water is 64,074,304,515.07 TZS (27,626,570 USD) in the investment year and 39,828,547,584 TZS (17,172,659 USD) per year then after. This value was unrevealed and not considered in decision-making, leading to prolonged degradation. It is advised from this study for regulatory authorities to conduct valuation studies and use them to refine appropriate decisions to promote conservation and avoid unnecessary financial losses. The final value should also take into consideration the intrinsic value that water has, not only the direct one that is easily traceable.

The Status of Domestic Water Supply and its Implications: A Case of Kondoa District Council, Tanzania

This study investigated about the Status of domestic water supply and its implications in Kondoa District Council, Tanzania. The study employed the descriptive cross-sectional design. The target population was 6126 households from two Wards (Kikore and Mnenia) in the Kondoa District Council. The study used the Yamane formula to determine the sample size of 376 respondents. Thereafter, 376 respondents (household heads) were drawn from the population through the systematic random sampling. Secondly, key informants (government officials from higher and lower LGAs) were selected purposely by virtue of positions they held. The study used a questionnaire survey, focus group discussions, in-depth interviews and observations as sources of data. Quantitative data was analyzed by using descriptive statistics. Data from in-depth interview, observation and FGDs was analyzed by the thematic method. The study concludes that physical access to water points was crucial as the majority of respondents received water beyond the target of 30 minutes specified in policy statements. Furthermore, there is inadequate water quality. Therefore, Kondoa District Council was not on course to meet the established standards outlined in the national water policy of 2002 and the overall target for water access set in Tanzania's development vision for 2025. One of key recommendations is the empowerment of the water users, water institutions and village leaders who can make huge contributions to improve the status of water service delivery in terms of physical access, quality and quantity.

Heat transfer and performance enhancement investigation of biomimetic honeycomb gas coolers in transcritical CO2 heat pumps

CO2 air source heat pump heating technology has characteristics of strong adaptability to outdoor temperature in cold areas and high outlet temperature, which is widely used in heating and domestic hot water supply. A gas cooler is one of the crucial components in CO2 heat pump systems, while its performance and different structural forms will directly affect the performance of the whole CO2 heat pump system. In order to improve its heat transfer efficiency, a biomimetic honeycomb gas cooler is proposed in this paper, the steady-state simulation model of the biomimetic honeycomb gas cooler is established, and the reliability of the model is verified by experimental data. In addition, the effect of structural parameters and operating parameters on the heat transfer performance is studied, also the heat transfer performance of the biomimetic honeycomb gas cooler is compared with that of the internal spiral tube gas cooler and triple tube-in-tube gas cooler. The results show that the performance of the biomimetic honeycomb gas cooler can be effectively improved by reducing the water flow rate. Under the same working condition, the performance evaluation criteria1 of the 1st, 2nd and 3rd layer biomimetic honeycomb gas cooler s are about 193.4%, 239.9% and 357.0% higher than that of the internal spiral tube gas cooler, and about 197.2%, 205.9% and 237.7% higher than that of triple tube-in-tube gas cooler. This research is helpful to provide the reference for the design and optimization of this type of gas cooler and is conducive to the popularization and application of CO2 air source heat pumps.

Physico-chemical and microbiological assessment of domestic water supply in Bontoc, Mountain Province, Philippines

Abstract This study determined the water quality of the three major domestic water sources of Bontoc, Mountain Province, and recommended interventions to maintain water parameters within values set by the Philippine National Standards for Drinking Water (PNSDW). Results revealed that all the average values of the physico-chemical parameters measured during wet and dry seasons for the water samples from the different water sources and sampling points are within the allowable range except for turbidity and color during and just after typhoons and prolonged strong rainfalls. As to microbiological parameters, samples from the sources, storage tank, and distribution line have a very high total coliform count, and Escherichia coli content for both seasons. For heterotrophic plate count, only the water samples from Balabag Spring for both wet and dry seasons, from the storage tank during the wet season, and from Gakhan Spring during the dry season have acceptable values. Findings indicate the high vulnerability of the water sources to microbial contamination. Thus, water in all sources is not potable and is therefore not recommended for drinking purposes in its present condition. To address the water supply quality problems, filtration systems may be included in the water system design, the intake tanks, or a new reservoir.

Characterization and assessment of hydrological droughts using GloFAS streamflow data for the Narmada River Basin, India.

Hydrological droughts severely affect the demand of water for domestic water supply, irrigation, hydropower generation, and several other purposes. The pervasiveness and consequences of hydrological droughts necessitate a thorough investigation of their characteristics, which is hindered due to unavailability of continuous streamflow records at desirable resolutions. This study aims to assess the hydrological drought characteristics and their spatial distribution using high-resolution Global Flood Awareness System (GloFAS) v3.1 streamflow data for the period 1980 to 2020. Streamflow Drought Index (SDI) was used to characterize droughts at 3-, 6-, 9-, and 12-monthly timescales starting from June, i.e., the start of water year in India. GloFAS is found to capture the spatial distribution of streamflow and its seasonal characteristics. The number of hydrological drought years over the basin varied from 5 to 11 during the study duration, implying that the basin is prone to frequent abnormal water deficits. Interestingly, the hydrological droughts are more frequent in the eastern portion of the basin, i.e., the Upper Narmada Basin. The trend analysis of multi-scalar SDI series using non-parametric Spearman's Rho test exhibited increasing drying trends in the easternmost portions. The results were not similar for the middle and western portions of the basin, which may bedue to presence of a large number of reservoirs in these regions and their systematic operations. This study highlights the importance of open-access global products that can be used for monitoring hydrological droughts, especially over ungauged catchments.

Revisiting the coupling reaction between 4-aminoantipyrine and phenols: a potential one-pot reaction pathway to 4,11- and 5,12-naphthoxazepine isomers

A while ago, this journal ( Canadian Journal of Chemistry) published a set of seminal studies that revealed the underlying mechanism supporting the widely used 4-aminoantipyrine (4-AAP)-based analytical technique for detecting phenols at low levels in domestic water supplies. The current paper revisits these studies, but with a primary focus on an aspect of the mechanism that synthesizes a 6- and a 7-membered heterocyclic ring containing both N and O in a single step. Here we report a rather unusual outcome of this aspect in which, while the same naphthoquinonimide product is produced in the oxidative coupling of 4-AAP to 1-naphthol in aqueous solution and in the condensation of 4-AAP with 1,4-naphthoquinone in chloroform, a similar pair of reactions with 2-naphthol and 1,2-naphthoquinone produces two oxazepine isomers instead. In one isomer, the 4-AAP/naphthol C–N and C–O linkages are at positions 1 and 2 of the naphthyl ring, respectively; in the other isomer, these linkages are at positions 2 and 1, respectively. This unexpected difference in a one-pot reaction at ambient temperature is potentially the flexibility needed to synthesize families of pharmaceutically relevant oxazepines. Spectroscopic features useful for identifying 12 heterocyclic compounds synthesized here, nine of which are new, are also provided.

Dissipation of environmental DDT and its metabolites in selected rivers of south-western Kenya

Rivers are the main source of domestic and industrial water supplies in Kenya. In this study, water sampling was done at eight upstream sites in the Kuja River catchment, Kenya, between October 2016 and April 2017, specifically to test for residue levels of the organochlorine pesticide, dichlorodiphenyltrichloroethane (p,p′-DDT), and its degradation products, dichlorodiphenyldichloroethylene (p,p′-DDE) and dichlorodiphenyldichloroethane (p,p′-DDD). The analysis was performed with gas chromatography coupled with electron-capture detection in an autosampler. Concentrations of these residues in the surface water samples ranged from below detection limit (BDL) to 1.1113 μg l-1 in the wet season, and from BDL to 2.007 μg l-1 in the dry season. Overall, the highest mean residue concentration was for p,p′-DDT (0.9669 ± 0.2994 μg l-1). The lowest mean concentration in the dry season was that of p,p′-DDE (0.1824 ± 0.0964 μg l-1), and in the wet season it was p,p′-DDD (0.0610 ± 0.0038 μg l-1). From our results it is evident that DDT is still in use and detectable in the study area, though the mean levels detected were below the acceptable thresholds for natural water as suggested by the World Health Organization (WHO). Except for a slightly higher mean spatial distribution of the metabolite p,p′-DDT, the resides were recorded as below the maximum admissible concentrations of pesticide residues in drinking water, as set out in WHO guidelines and by Kenya’s National Environment Management Authority (NEMA). Monitoring organochlorine pesticide contamination levels in Kenya’s water resources should be scaled up to leverage potential for a sustainable blue economy and in safeguarding human and environmental health.

Using commercial resin for ion exchange to remove hardness from domestic water supply

The commercially available resins, Amberlite (A) and NuoSep (B), were used as ion exchange softeners for domestic water supply. The image, particle size, swelling, and bulk density of both resins were studied. The functional group of resins was investigated by Fourier transform infrared (FTIR) spectroscopy. Batch and continuous experiments were carried out at time 0–180 min and flow rate 10–40 cm3/min, respectively. An increase in contact time increased the percentage of the resins’ ion exchange. In contrast, a higher water supply flow rate decreased the percentage of the resins’ ion exchange. The efficiencies of both resins were slightly reduced after three cycles of regeneration. The equation from the Yoon–Nelson model could also be used to predict the breakthrough curve of ion exchange.

Analysis of Water Supply in Hejin Sakura Valley Imitating Jiangnan-style Landscape

To ensure the domestic water and landscape water supply requirements of Hejin Sakura Valley Scenic Area, the water supply scheme of the artificial lake and scenic spot domestic water consumption assessment machine is optimized. Firstly, in view of the water resources situation in the area where the cherry blossom valley garden scenic spot is located, the necessity of pumping groundwater is pointed out; Secondly, combined with the basic information of hydrogeology and mountainous terrain, a scheme for pumping water supply from natural pipe wells is proposed; Finally, relying on FLAC3D software, three different pipe diameter pumping well models of 600mm, 700mm and 800mm are established, three-dimensional jet field analysis is carried out, and the optimal layout scheme of pipe diameter and position of pipe well is given. Studies have shown that the larger the well diameter, the greater the outlet flow rate, and the water output can be increased by 50~80m3/d for each 100mm tube well; The number of tube wells arranged is about 6, and it is recommended that a sufficient distance should be maintained between wells; The demand for pipe wells with different apertures varies between 1 and 2 mouths. The results of this paper can provide guidance for the construction of gardens in central China to solve the problem of water supply, and support and serve the construction of garden landscape.