A study was carried out between November 2010 and April 2011 to assess the availability and potability of water from alternative water sources in Harare, Zimbabwe＇s capital city. A survey of 256 households from a tot...A study was carried out between November 2010 and April 2011 to assess the availability and potability of water from alternative water sources in Harare, Zimbabwe＇s capital city. A survey of 256 households from a total of 10 high, medium and low income suburbs and informal settlements was undertaken to assess types and amount of water consumed. This was complemented by a water quality study that assessed a selection of physical, chemical and bacteriological parameters. Quality of the water was compared to World Health Organisation and Zimbabwean standards. All households were found to rely on water sources other than municipal water. Per capita water consumption across settlements was found to be below the recommended upper limit of 50 litres per person per day except in one high income suburb, but above the recommended lower limit of 15 litres. All samples were within the acceptable limit for color but above the acceptable limit for turbidity. Chemical parameters were found to be within the acceptable range except for total hardness, where 35% of the samples were above the acceptable range. About a third of the samples from low income suburbs and informal settlements were above the acceptable limit for faecal and total coliforms.展开更多
The present study aims to develop a new hybrid Fuzzy Simulink model to assess the groundwater quality levels in Tiruchirappalli city, South India. Water quality management is an important issue in the modern times. Th...The present study aims to develop a new hybrid Fuzzy Simulink model to assess the groundwater quality levels in Tiruchirappalli city, South India. Water quality management is an important issue in the modern times. The data collected for Tiruchirappalli city have been utilized to develop the approach. This is illustrated with seventy nine groundwater samples collected from Tiruchirappalli city Corporation, South India. The characteristics of the groundwater for this plain were monitored during the years 2006 and 2008. The quality of groundwater at several established stations within the plain were assessed using Fuzzy Logic (FL) and GIS maps. The results of the calculated FL and GIS maps with the monitoring study have yielded good agreement. Groundwater quality for potability indicated high to moderate water pollution levels at Srirangam, Ariyamangalam, Golden Rock and K. Abisekapurm zones of the study area, depending on factors such as depth to groundwater, constituents of groundwater and vulnerability of groundwater to pollution. Fuzzy logic simulation approach has shown to be a practical, simple and useful tool to assess groundwater quality assessment for potability. This approach is capable of showing and updating the water quality assessment for drinking.展开更多
The purpose of this study is to assess the physical and chemical quality of borehole water intended for consumption in the collines department in Benin. At the end of a sampling campaign, twenty-one (21) drinking wate...The purpose of this study is to assess the physical and chemical quality of borehole water intended for consumption in the collines department in Benin. At the end of a sampling campaign, twenty-one (21) drinking water points were sampled. Different physico-chemical parameters were measured using standard analysis methods. The results of the analysis of the samples, showed that the groundwater of the department of the hills </span></span><span><span><span style="font-family:"">is</span></span></span><span><span><span style="font-family:""> characterized by a neutral pH and an average electrical conductivity in accordance with the WHO and Benin standard relating to the potability of groundwater. With this pH neutrality which would be linked to the nature of geological formations made up of crystalline rocks, the water in the hills is moderately hard with hardness values </span><span></span></span></span><span><span><span style="font-family:"">of 208 mg/L on average for magnesium ions of 22.54 mg/L </span></span></span><span><span><span style="font-family:"">on</span></span></span><span><span><span style="font-family:""> average and calcium ions of the order of 46.03 mg/L on average at the scale of the various localities and an alkalinity is of 43.81 mg/L on average. The </span><span><span></span></span></span></span><span><span><span style="font-family:""><span> </span>values </span><span></span></span></span><span><span><span style="font-family:"">between 0 and 163.91 mg/L are low in the South-East and very high, even exceeding the standard accepted by WHO in the West and North-East of the study area. This nitrate pollution and the fairly high levels of organic matter in total nitrogen observed in the groundwater of the hills could also have an impact on the vulnerability of the water table. And this pollution with nitrates associated with electrical conductivity and chloride levels modifies and degrades from one drinking water point to another the potability of underground water in the hills.展开更多
The study investigates the impact of the Syrian crisis and the recent drought on the potable water situation in Northwest Syria, comparing various aspects of water availability and quality before and after 2011. 380 k...The study investigates the impact of the Syrian crisis and the recent drought on the potable water situation in Northwest Syria, comparing various aspects of water availability and quality before and after 2011. 380 key-informants were surveyed, including water-well owners, well-digging companies, water-trucking suppliers, agricultural pharmacies, and service offices within local councils. The surveys covered all nine districts in northwestern Syria across the Aleppo and the Idleb governorates. The survey findings reveal significant shifts in water sources, an almost halving in water availability and per capita consumption, and a notable decrease in water quality. Coping mechanisms include random well drilling and reduced hygiene practices. Water pumping stations face challenges with functionality, and there is a shift towards clean energy sources, particularly solar energy. Challenges identified by the survey respondents include drought, fuel costs, and damaged water networks. The study highlights the urgency of addressing the potable water crisis in Northwest Syria and suggests specific interventions to enhance water sustainability and governance.展开更多
A means to develop a comparative assessment of the risks of available wastewater effluent disposal options on a local scale needs to be developed to help local decision-makers make decisions on options such as direct ...A means to develop a comparative assessment of the risks of available wastewater effluent disposal options on a local scale needs to be developed to help local decision-makers make decisions on options such as direct or indirect potable reuse options. These options have garnered more interest as a result of water supply limitations in many urban areas. This risk assessment was developed from a risk assessment developed at the University of Miami in 2001 and Florida Atlantic University (FAU) in 2023. Direct potable reuse and injection wells were deemed to have the lowest risk in the most recent study by FAU. However, the injection well option may not be available everywhere. As a result, a more local means to assess exposure risk is needed. This paper outlines the process to evaluate the public health risks associated with available disposal alternatives which may be very limited in some areas. The development of exposure pathways can help local decision-makers define the challenges, and support later expert level analysis upon which public health decisions are based.展开更多
A significant portion of the national water supply can be attributed to de facto or unplanned potable reuse, though the extent of its contribution is difficult to estimate. Fortunately, the contribution of Water Resou...A significant portion of the national water supply can be attributed to de facto or unplanned potable reuse, though the extent of its contribution is difficult to estimate. Fortunately, the contribution of Water Resource Recovery Facility (WRRF) effluent to waters that supply drinking water treatment plants has been documented by some communities. In the United States (US), among the top 25 most impacted drinking water treatment plants by upstream WRRF, 16% of the influent flow to the drinking water treatment plant under average streamflow and up to 100% under low-flow conditions is WRRF effluent. Currently, the full extent of de facto reuse in the US may be much higher because of population growth. The scenario is no different for Beaufort-Jasper Water and Sewer Authority (BJWSA) in South Carolina, US, with contributions to the Savannah River originating from numerous WRRF and other upstream dischargers. South Carolina coastal utilities such as BJSWA are considering direct and indirect potable reuse options, driven by disposal limitations and challenges. Currently, South Carolina does not have a framework, guidelines, or regulations for reuse, but discussions have started among the regulated community. In addition to understanding the extent of de facto reuse, the state will need to develop standards and best practices to enable future adoption of planned potable reuse solutions to water resources challenges. Such guidance should address human health risk management and technical considerations regarding treatment in addition to other factors, including source control, storage, fail-safe operation, monitoring, non-cost factors, and public acceptance. This study conducted a mapping assessment specific to BJWSA, sampled at four locations on Savannah River, and observed that de facto reuse is approximately 4.6% to 5.9% during low-flow months and is within the range generally observed nationwide. When coupled with evidence that planned potable reuse can improve human health and environmental risks, this practice is a meaningful option in the water supply portfolio for many utilities.展开更多
The experimental and analytical investigation was conducted on a solar-powered single-effect distillation (SED). The evaporator was designed to be an electrical evaporator as opposed to the steam evaporator that exist...The experimental and analytical investigation was conducted on a solar-powered single-effect distillation (SED). The evaporator was designed to be an electrical evaporator as opposed to the steam evaporator that existed previously. Using sun-tracking solar panels, the electrical evaporator in the designed distillation unit was powered by solar energy. Approximately 20 kWh was utilized by the small-scale distillation apparatus. This type of design is mobile, so remote areas and countries with fragile economies can utilize it on a small or large scale. Utilizing the principles of energy and mass conservation, the amount of distillate water and power required for a single unit was determined, at the low salinity (2200 PPM) with fixed boiling point temperature (Tb = 75˚C), the unit performance is approx. 98.4%. The experimental results and those derived from a mathematical model were compared, and both showed strong accord. Using engineering equation solver (EES) software, a computer program was developed for this research scenario.展开更多
This paper describes the utility of fuzzy Simulink model to assess the groundwater quality levels in Tiruchirappalli city, S. India. Water quality management is an important issue in the modern times. The study aimed ...This paper describes the utility of fuzzy Simulink model to assess the groundwater quality levels in Tiruchirappalli city, S. India. Water quality management is an important issue in the modern times. The study aimed at examining the influence of multiple parameters of ground water on potable quality. The data collected for Tiruchirappalli city have been utilized to develop fuzzy Simulink approach. This is illustrated with seventy nine groundwater samples collected from Tiruchirappalli corporation, S. India. The characteristics of the groundwater groundwater for this plain were monitored during the years 2006 and 2008. The quality of groundwater at several established stations within the plain were assessed using Fuzzy simulation. The results of the calculated fuzzy logic Simulink model and the monitoring study have yielded good agreement. Groundwater quality for potability indicated high to moderate water pollution levels at Srirangam, Ariyamangalam, Golden Rock and K. Abisekapuram depending on factors such as depth to groundwater, constituents of groundwater and vulnerability of groundwater to pollution. Fuzzy logic simulation approach was a practical, simple and useful tool to assess groundwater quality. This approach was capable of showing the water quality assessment for drinking on fuzzy Simulink展开更多
Dhaka is one of the most densely-populated megacities in the world. Water supply problem is acute in this city, but the quality of drinking water has tremendous importance as potability. This study was aimed at compar...Dhaka is one of the most densely-populated megacities in the world. Water supply problem is acute in this city, but the quality of drinking water has tremendous importance as potability. This study was aimed at comparing various physicochemical and microbiological parameters which are very much relevant for the drinking water quality of Dhaka city of Bangladesh. A total of 80 samples from 11 collection point of different places were collected over ten months. After that, the samples were examined by a different measuring device for physicochemical parameter testing. Considering physicochemical parameters, all water samples were within the limit for pH. However, 53.75% water had unsatisfactory for chlorine level. Total Dissolve Solid (TDS), hardness, iron, and alkalinity based unsatisfactory were 28.75%, 15.0%, 8.75%, and 3.75% respectively. Five parameters had taken into consideration to measure the microbiological quality. The cultural and biochemical methods showed that 80 water samples have a different range of contamination. The total aerobic count was unsatisfactory for 53.75% samples. Sixty-one samples were found coliform contaminated that is 76.25% of the total samples and 58.75% sample was carried fecal substances. E. coli and Vibrio was unsatisfactory as 61.25% and13.75% respectively. This study revealed that how much safe is supplied water of a municipal water supplier.展开更多
This study provides a characterization of potential health risk associated with groundwater Nitrates in Akkar plain in Taturs governorate in Syria. Six villages were chosen for Nitrates analysis in artesian wells. The...This study provides a characterization of potential health risk associated with groundwater Nitrates in Akkar plain in Taturs governorate in Syria. Six villages were chosen for Nitrates analysis in artesian wells. The results show that Nitrates concentrations are above the natural level but still below the level of water potability and measures have to be taken to prevent Nitrates accumulation in groundwater. Comparing Nitrates dose in young children diet with reference dose and calculating the hazard index give the noncarcinogenic risk (Methemoglobinemia). Carcinogenic risk of drinking well waters with Nitrates is calculated in a probabilistic-fuzzy framework. The role of Bacterial contamination of water and its association with Nitrates pollution is discussed and we found that the two pollutants are not correlated in Akkar plain, because Nitrates come principally from fertilizers in this area while fecal coliforms come from landfill leachates and untreated wastewaters. Nitrates and FC play associated roles in gastro-intestinal disturbance and Methemoglobinemia.展开更多
In this article,we present the results of Eastern Mitidja basin groundwater chemical analysis realized by the Algerian water laboratory at National Water Resources Agency(Algiers)in October-November 1991.We try to sho...In this article,we present the results of Eastern Mitidja basin groundwater chemical analysis realized by the Algerian water laboratory at National Water Resources Agency(Algiers)in October-November 1991.We try to show a synthetic cartography of some physic-chemical parameters in this area,the spatial quality evolution of groundwater and its irrigation aptitude.The groundwater of Eastern Mitidja basin are bicarbonate-calcareous with magnesium by place sulfated.The mineralization of groundwaters is weak in the high stream and strong in downstream(proximity of the sea).The concentrations of nitrates remain below from the World Health Organization norms over the whole of basin study.Eastern Mitidja basin groundwaters are not dangerous and can be used for irrigation.展开更多
The problem of water supply from the public distribution network still poses very serious problems in many cities in developing countries. Intermittent water supply pushes some households to build underground reinforc...The problem of water supply from the public distribution network still poses very serious problems in many cities in developing countries. Intermittent water supply pushes some households to build underground reinforced concrete tanks for water storage to cope with unwanted water breaks. This study that relies on the results of a survey of households in some areas of the city of Brazzaville (Republic of Congo) aims to verify the importance that users attach to the quality of the works constructed. Indeed, the reliability of the tanks resulting in their impermeability to the external environment has a direct impact on the quality of stored water and therefore the use that is made of water daily. Five areas were selected because of their soil moisture. By 256 tanks identified, 143 are made of reinforced concrete and 113 in masonry. The coating materials used to seal the walls are preferably the earthenware tiles (64% of tanks), then the Sika cement (31%). Food painting (5%) is only rarely used. However, 66% of households are not assured of the potability of the water stored. A significant number of households (46%) think that the stored water could be contaminated with noxious substances seeping from the outside through the walls of the tanks. The issue of sealing of underground water tanks, especially in areas where the water table is shallow, seems concerned users.展开更多
Water supply and sanitation demands are foreseen to face enormous challenges over the coming decades to meet the fast growing needs in a global perspective. Significant growth in the industry is predicted and membrane...Water supply and sanitation demands are foreseen to face enormous challenges over the coming decades to meet the fast growing needs in a global perspective. Significant growth in the industry is predicted and membrane separation technologies have been identified as one of the possible solutions to meet future demands. Application and implementation of membrane technology is expected both in production of potable water as well as in treatment of wastewater. In potable water production membranes are substituting conventional separation technologies due to the superior performance, potential for less chemical use and sludge production, as well as the potential to fulfill hygienic barrier requirements. Membrane bio-reactor （MBR） technology is probably the membrane process which has had most success and has the best prospects for the future in wastewater treatment. Trends and developments indicate that this technology is becoming accepted and is rapidly becoming the best available technology for many wastewater treatment applications. A major drawback of MBR systems is membrane fouling. Studies have shown that fouling mitigation in MBR systems can potentially be done by coupling coagulation and flocculation to the process.展开更多
In order to remove the low turbidity present in surface water, a novel metal-polysilicate coagulant was used to treat the raw water taken from Tanjiang River in Guangdong Province. This study on the effects of Al/Fe ...In order to remove the low turbidity present in surface water, a novel metal-polysilicate coagulant was used to treat the raw water taken from Tanjiang River in Guangdong Province. This study on the effects of Al/Fe molar ratio on the performance of a complex compound formed by polysilicic acid, aluminium and ferric salt (PAFS) showed that PAFS with Al/Fe ratio of 10:3 seemed to have the best coagulation performance in removing turbidity and color. Experimental results showed that under the conditions of polymerization time of 15 d, sedimentation time of 12 min, and pH of 6?8, PAFS with Al/Fe molar ratio of 10:3 had the best coagulation efficiency and lowest residual Al concentration. The turbid- ity decreased from 23.8 NTU to 3.23 NTU and the residual Al concentration was only 0.165 mg/L in the product water. It could be speculated that colloidal impurities and particulate Al were removed by adsorption bridging and electrical neu- tralization of long chain inorganic polymer coagulants.展开更多
Objective:To ascertain the level of intestinal parasites vis-a-vis the quality of housing and water supply,and sanitary conditions among the people of Kuraje village in Zamfara state. Methods:The study was cross secti...Objective:To ascertain the level of intestinal parasites vis-a-vis the quality of housing and water supply,and sanitary conditions among the people of Kuraje village in Zamfara state. Methods:The study was cross sectional in nature.Individual households were selected using systematic random sampling methods and pre-tested questionnaires were administered to all the members of each household.Stool samples were collected and processed using standard laboratory procedures.Housing conditions,sources of water and sanitary conditions of the households were also inspected.Results were analysed using Epi Info 2006 model.Results: The prevalence of intestinal parasites was 67.0%(347/519).72.3%(251/347),17.0%(59/347),and 10.7%(37/347) had one,two and three or more parasites,respectively.The associated factors with intestinal parasites were poor housing and sanitary conditions,lack of potable water and illiteracy.The commonest parasites encountered were hookworm(22.0%),Ascaris lumbricoides (18.5%),and Strongyloides stercoralis(15.6%) while the least common was Enterobius vermicularis (1.6%).Others were Giardia lamblia(5.7%),Hymenolepsis nana(5.0%),Trichuris trichiura(8.8%), Entamoeba histolytica(14.4%) and Schistosoma mansoni(8.4%).Conclusions:The infection rate of intestinal parasites in Kuraje village is high.More efforts should be intensified towards improvement in sanitary and housing standards,supply of potable water and institution of a more comprehensive literacy programme for the people of the community.展开更多
Following biological treatment, wastewater continues to have endotoxic active materials. However, because there is a trend of potable reuse and because endotoxic active materials potentially have harmful effects on hu...Following biological treatment, wastewater continues to have endotoxic active materials. However, because there is a trend of potable reuse and because endotoxic active materials potentially have harmful effects on human health, their removal from water is crucial. Lipopolysaccharide endotoxin has hydrophobic groups, and their removal using a coagulation-flocculation alternative is believed to be efficient. Thus, their removal from reclaimed wastewater using the coagulation-flocculation process was assessed. Secondary effluent samples from a wastewater treatment plant located in Sapporo, Japan, were investigated. It was found that this process gave satisfactory results in removing endotoxins, with an optimum removal rate of up to 40.5%. The endotoxin removal was maximized by adjusting the pH at the low range 4 - 5.5, with an aluminum sulfate dose of 80 mg/L. Further increases of the coagulant dose did not improve the removal efficiency. DOC and turbidity removal were at their optimum at higher pH range 5.5 - 6.5. Thus coagulation and flocculation could be considered as the first barrier and should be followed by other treatments to safely reuse reclaimed wastewater.展开更多
An accurate chlorine bulk decay model is needed to ensure that potable water meets the microbial and the chemical safeties at the treatment plant and throughout the distribution. Among the mathematical models availabl...An accurate chlorine bulk decay model is needed to ensure that potable water meets the microbial and the chemical safeties at the treatment plant and throughout the distribution. Among the mathematical models available,the general second-order chlorine bulk decay model( GBDM) is the most fundamentally sound.Application of the GBDM,however,has been hindered by its numerous fictive parameters and lack of an analytical solution. This theoretical work removes the two obstacles. The GBDM is solved through transformation and integration. The analytical solution provides deep insights into the GBDM and facilitates the parameterization and sensitivity analysis. The background natural organic matter( NOM) is characterized with the probabilistic distribution of functional groups. It reveals that the mean of the function group distribution is correlated with the initial chlorine decay rate coefficient( κ_0). A simple formula is developed to determine κ_0 directly from the initial chlorine decay. The theoretical treatment reduces the fictive parameters to a minimum. For the common lognormal distribution,the GBDM needs only three parameters,well defined as initial chlorine demand X_0,median rate coefficient km,and heterogeneity index σ. For more complicated scenarios,composite distributions are constructed through superposition of individual distributions. A highlighted example is to predict chlorine decay in blends of different waters. With the theoretical and mathematical advancement here,the GBDM can be applied effectively to any reactive background matter in any reaction systems.展开更多
Peninsulas are exceptional areas loved to be developed uniquely in most part of the globe. Lekki Peninsulas in Lagos, Nigeria is fast growing, benefitting from similar fortunes such as modern residential suburbs, free...Peninsulas are exceptional areas loved to be developed uniquely in most part of the globe. Lekki Peninsulas in Lagos, Nigeria is fast growing, benefitting from similar fortunes such as modern residential suburbs, free trade zone, airport;and tourism are springing up but without adequate potable water for sustainable development. Reconnaissance surveys followed by an In-Depth-Interview were carried out. The commonest sources are sachet, bottled and borehole waters. Sachet and bottled waters are readily available but at unaffordable costs. The most frequently available is borehole, but chemical, physical/organoleptic and microbiological analysis show that the compositions are not within WHO permissible standards. Sustainability is in jeopardy. Individuals, organizations and businesses spend average of 15% of their income on treatments to meet acceptable standards. There are needs to bridge the gap between the residents taking untreated poor water and the few that take WHO standardized waters. A Simple Water Treatment Device is recommended. The device consists of four chambers, two pumping machines, alum and chlorine for treatment. It is equipped with 12 to 13 valves (depending on the position of the chambers);and the entire system is powered by electricity. It will control water borne diseases such as typhoid, schistotomiasis, diarrhea and dysentery, hepatitis, cholera and others;potable water will be available for domestic, recreational and industrial uses;enough for use in the Free Trade Zone and at the forth coming airport;the Eighteen Golf Course will not have challenges of potable water;and forces and military formations within and around the peninsula can rely on the source for every use. It is estimated that the system that can provide average of 100,000 liters of water a day will cost N720,000:00, that is, outside the cost of electricity. The system requires regular maintenance. This device could be applied anywhere.展开更多
A comprehensive study was conducted to evaluate a rural community’s efforts to solve its potable water problem. Residents of St. Margaret village has built a rudimentary water storage facility through their community...A comprehensive study was conducted to evaluate a rural community’s efforts to solve its potable water problem. Residents of St. Margaret village has built a rudimentary water storage facility through their community efforts and run a network of water supply to the households of the village. The study analyzed the water quality of the reservoir for physical, chemical and microbiological parameters by using standard water quality measurements and compared it between the wet and the dry seasons. The results indicate that the temperature and the pH were highest in the month of April. The phosphate level was high during the month of November whereas the dissolved oxygen level was lowest during November. The presence of fecal coliforms and other pathogenic microbes such as Salmonella and Shigella suggested that the water bodies are not safe for human consumption. The survey of the households in the village also revealed that health ailments associated with gastrointestinal tract are common among the people using the water for drinking purpose. The community’s effort in finding solution to their potable water problem has been demonstrated in the design and execution of the rudimentary reservoir in the St. Margaret village. Although majority of the inhabitants of the village have only primary-level education, they were able to carry out a major engineering project.展开更多
文摘A study was carried out between November 2010 and April 2011 to assess the availability and potability of water from alternative water sources in Harare, Zimbabwe＇s capital city. A survey of 256 households from a total of 10 high, medium and low income suburbs and informal settlements was undertaken to assess types and amount of water consumed. This was complemented by a water quality study that assessed a selection of physical, chemical and bacteriological parameters. Quality of the water was compared to World Health Organisation and Zimbabwean standards. All households were found to rely on water sources other than municipal water. Per capita water consumption across settlements was found to be below the recommended upper limit of 50 litres per person per day except in one high income suburb, but above the recommended lower limit of 15 litres. All samples were within the acceptable limit for color but above the acceptable limit for turbidity. Chemical parameters were found to be within the acceptable range except for total hardness, where 35% of the samples were above the acceptable range. About a third of the samples from low income suburbs and informal settlements were above the acceptable limit for faecal and total coliforms.
文摘The present study aims to develop a new hybrid Fuzzy Simulink model to assess the groundwater quality levels in Tiruchirappalli city, South India. Water quality management is an important issue in the modern times. The data collected for Tiruchirappalli city have been utilized to develop the approach. This is illustrated with seventy nine groundwater samples collected from Tiruchirappalli city Corporation, South India. The characteristics of the groundwater for this plain were monitored during the years 2006 and 2008. The quality of groundwater at several established stations within the plain were assessed using Fuzzy Logic (FL) and GIS maps. The results of the calculated FL and GIS maps with the monitoring study have yielded good agreement. Groundwater quality for potability indicated high to moderate water pollution levels at Srirangam, Ariyamangalam, Golden Rock and K. Abisekapurm zones of the study area, depending on factors such as depth to groundwater, constituents of groundwater and vulnerability of groundwater to pollution. Fuzzy logic simulation approach has shown to be a practical, simple and useful tool to assess groundwater quality assessment for potability. This approach is capable of showing and updating the water quality assessment for drinking.
文摘The purpose of this study is to assess the physical and chemical quality of borehole water intended for consumption in the collines department in Benin. At the end of a sampling campaign, twenty-one (21) drinking water points were sampled. Different physico-chemical parameters were measured using standard analysis methods. The results of the analysis of the samples, showed that the groundwater of the department of the hills </span></span><span><span><span style="font-family:"">is</span></span></span><span><span><span style="font-family:""> characterized by a neutral pH and an average electrical conductivity in accordance with the WHO and Benin standard relating to the potability of groundwater. With this pH neutrality which would be linked to the nature of geological formations made up of crystalline rocks, the water in the hills is moderately hard with hardness values </span><span></span></span></span><span><span><span style="font-family:"">of 208 mg/L on average for magnesium ions of 22.54 mg/L </span></span></span><span><span><span style="font-family:"">on</span></span></span><span><span><span style="font-family:""> average and calcium ions of the order of 46.03 mg/L on average at the scale of the various localities and an alkalinity is of 43.81 mg/L on average. The </span><span><span></span></span></span></span><span><span><span style="font-family:""><span> </span>values </span><span></span></span></span><span><span><span style="font-family:"">between 0 and 163.91 mg/L are low in the South-East and very high, even exceeding the standard accepted by WHO in the West and North-East of the study area. This nitrate pollution and the fairly high levels of organic matter in total nitrogen observed in the groundwater of the hills could also have an impact on the vulnerability of the water table. And this pollution with nitrates associated with electrical conductivity and chloride levels modifies and degrades from one drinking water point to another the potability of underground water in the hills.
文摘The study investigates the impact of the Syrian crisis and the recent drought on the potable water situation in Northwest Syria, comparing various aspects of water availability and quality before and after 2011. 380 key-informants were surveyed, including water-well owners, well-digging companies, water-trucking suppliers, agricultural pharmacies, and service offices within local councils. The surveys covered all nine districts in northwestern Syria across the Aleppo and the Idleb governorates. The survey findings reveal significant shifts in water sources, an almost halving in water availability and per capita consumption, and a notable decrease in water quality. Coping mechanisms include random well drilling and reduced hygiene practices. Water pumping stations face challenges with functionality, and there is a shift towards clean energy sources, particularly solar energy. Challenges identified by the survey respondents include drought, fuel costs, and damaged water networks. The study highlights the urgency of addressing the potable water crisis in Northwest Syria and suggests specific interventions to enhance water sustainability and governance.
文摘A means to develop a comparative assessment of the risks of available wastewater effluent disposal options on a local scale needs to be developed to help local decision-makers make decisions on options such as direct or indirect potable reuse options. These options have garnered more interest as a result of water supply limitations in many urban areas. This risk assessment was developed from a risk assessment developed at the University of Miami in 2001 and Florida Atlantic University (FAU) in 2023. Direct potable reuse and injection wells were deemed to have the lowest risk in the most recent study by FAU. However, the injection well option may not be available everywhere. As a result, a more local means to assess exposure risk is needed. This paper outlines the process to evaluate the public health risks associated with available disposal alternatives which may be very limited in some areas. The development of exposure pathways can help local decision-makers define the challenges, and support later expert level analysis upon which public health decisions are based.
文摘A significant portion of the national water supply can be attributed to de facto or unplanned potable reuse, though the extent of its contribution is difficult to estimate. Fortunately, the contribution of Water Resource Recovery Facility (WRRF) effluent to waters that supply drinking water treatment plants has been documented by some communities. In the United States (US), among the top 25 most impacted drinking water treatment plants by upstream WRRF, 16% of the influent flow to the drinking water treatment plant under average streamflow and up to 100% under low-flow conditions is WRRF effluent. Currently, the full extent of de facto reuse in the US may be much higher because of population growth. The scenario is no different for Beaufort-Jasper Water and Sewer Authority (BJWSA) in South Carolina, US, with contributions to the Savannah River originating from numerous WRRF and other upstream dischargers. South Carolina coastal utilities such as BJSWA are considering direct and indirect potable reuse options, driven by disposal limitations and challenges. Currently, South Carolina does not have a framework, guidelines, or regulations for reuse, but discussions have started among the regulated community. In addition to understanding the extent of de facto reuse, the state will need to develop standards and best practices to enable future adoption of planned potable reuse solutions to water resources challenges. Such guidance should address human health risk management and technical considerations regarding treatment in addition to other factors, including source control, storage, fail-safe operation, monitoring, non-cost factors, and public acceptance. This study conducted a mapping assessment specific to BJWSA, sampled at four locations on Savannah River, and observed that de facto reuse is approximately 4.6% to 5.9% during low-flow months and is within the range generally observed nationwide. When coupled with evidence that planned potable reuse can improve human health and environmental risks, this practice is a meaningful option in the water supply portfolio for many utilities.
文摘The experimental and analytical investigation was conducted on a solar-powered single-effect distillation (SED). The evaporator was designed to be an electrical evaporator as opposed to the steam evaporator that existed previously. Using sun-tracking solar panels, the electrical evaporator in the designed distillation unit was powered by solar energy. Approximately 20 kWh was utilized by the small-scale distillation apparatus. This type of design is mobile, so remote areas and countries with fragile economies can utilize it on a small or large scale. Utilizing the principles of energy and mass conservation, the amount of distillate water and power required for a single unit was determined, at the low salinity (2200 PPM) with fixed boiling point temperature (Tb = 75˚C), the unit performance is approx. 98.4%. The experimental results and those derived from a mathematical model were compared, and both showed strong accord. Using engineering equation solver (EES) software, a computer program was developed for this research scenario.
文摘This paper describes the utility of fuzzy Simulink model to assess the groundwater quality levels in Tiruchirappalli city, S. India. Water quality management is an important issue in the modern times. The study aimed at examining the influence of multiple parameters of ground water on potable quality. The data collected for Tiruchirappalli city have been utilized to develop fuzzy Simulink approach. This is illustrated with seventy nine groundwater samples collected from Tiruchirappalli corporation, S. India. The characteristics of the groundwater groundwater for this plain were monitored during the years 2006 and 2008. The quality of groundwater at several established stations within the plain were assessed using Fuzzy simulation. The results of the calculated fuzzy logic Simulink model and the monitoring study have yielded good agreement. Groundwater quality for potability indicated high to moderate water pollution levels at Srirangam, Ariyamangalam, Golden Rock and K. Abisekapuram depending on factors such as depth to groundwater, constituents of groundwater and vulnerability of groundwater to pollution. Fuzzy logic simulation approach was a practical, simple and useful tool to assess groundwater quality. This approach was capable of showing the water quality assessment for drinking on fuzzy Simulink
文摘Dhaka is one of the most densely-populated megacities in the world. Water supply problem is acute in this city, but the quality of drinking water has tremendous importance as potability. This study was aimed at comparing various physicochemical and microbiological parameters which are very much relevant for the drinking water quality of Dhaka city of Bangladesh. A total of 80 samples from 11 collection point of different places were collected over ten months. After that, the samples were examined by a different measuring device for physicochemical parameter testing. Considering physicochemical parameters, all water samples were within the limit for pH. However, 53.75% water had unsatisfactory for chlorine level. Total Dissolve Solid (TDS), hardness, iron, and alkalinity based unsatisfactory were 28.75%, 15.0%, 8.75%, and 3.75% respectively. Five parameters had taken into consideration to measure the microbiological quality. The cultural and biochemical methods showed that 80 water samples have a different range of contamination. The total aerobic count was unsatisfactory for 53.75% samples. Sixty-one samples were found coliform contaminated that is 76.25% of the total samples and 58.75% sample was carried fecal substances. E. coli and Vibrio was unsatisfactory as 61.25% and13.75% respectively. This study revealed that how much safe is supplied water of a municipal water supplier.
文摘This study provides a characterization of potential health risk associated with groundwater Nitrates in Akkar plain in Taturs governorate in Syria. Six villages were chosen for Nitrates analysis in artesian wells. The results show that Nitrates concentrations are above the natural level but still below the level of water potability and measures have to be taken to prevent Nitrates accumulation in groundwater. Comparing Nitrates dose in young children diet with reference dose and calculating the hazard index give the noncarcinogenic risk (Methemoglobinemia). Carcinogenic risk of drinking well waters with Nitrates is calculated in a probabilistic-fuzzy framework. The role of Bacterial contamination of water and its association with Nitrates pollution is discussed and we found that the two pollutants are not correlated in Akkar plain, because Nitrates come principally from fertilizers in this area while fecal coliforms come from landfill leachates and untreated wastewaters. Nitrates and FC play associated roles in gastro-intestinal disturbance and Methemoglobinemia.
文摘In this article,we present the results of Eastern Mitidja basin groundwater chemical analysis realized by the Algerian water laboratory at National Water Resources Agency(Algiers)in October-November 1991.We try to show a synthetic cartography of some physic-chemical parameters in this area,the spatial quality evolution of groundwater and its irrigation aptitude.The groundwater of Eastern Mitidja basin are bicarbonate-calcareous with magnesium by place sulfated.The mineralization of groundwaters is weak in the high stream and strong in downstream(proximity of the sea).The concentrations of nitrates remain below from the World Health Organization norms over the whole of basin study.Eastern Mitidja basin groundwaters are not dangerous and can be used for irrigation.
文摘The problem of water supply from the public distribution network still poses very serious problems in many cities in developing countries. Intermittent water supply pushes some households to build underground reinforced concrete tanks for water storage to cope with unwanted water breaks. This study that relies on the results of a survey of households in some areas of the city of Brazzaville (Republic of Congo) aims to verify the importance that users attach to the quality of the works constructed. Indeed, the reliability of the tanks resulting in their impermeability to the external environment has a direct impact on the quality of stored water and therefore the use that is made of water daily. Five areas were selected because of their soil moisture. By 256 tanks identified, 143 are made of reinforced concrete and 113 in masonry. The coating materials used to seal the walls are preferably the earthenware tiles (64% of tanks), then the Sika cement (31%). Food painting (5%) is only rarely used. However, 66% of households are not assured of the potability of the water stored. A significant number of households (46%) think that the stored water could be contaminated with noxious substances seeping from the outside through the walls of the tanks. The issue of sealing of underground water tanks, especially in areas where the water table is shallow, seems concerned users.
文摘Water supply and sanitation demands are foreseen to face enormous challenges over the coming decades to meet the fast growing needs in a global perspective. Significant growth in the industry is predicted and membrane separation technologies have been identified as one of the possible solutions to meet future demands. Application and implementation of membrane technology is expected both in production of potable water as well as in treatment of wastewater. In potable water production membranes are substituting conventional separation technologies due to the superior performance, potential for less chemical use and sludge production, as well as the potential to fulfill hygienic barrier requirements. Membrane bio-reactor （MBR） technology is probably the membrane process which has had most success and has the best prospects for the future in wastewater treatment. Trends and developments indicate that this technology is becoming accepted and is rapidly becoming the best available technology for many wastewater treatment applications. A major drawback of MBR systems is membrane fouling. Studies have shown that fouling mitigation in MBR systems can potentially be done by coupling coagulation and flocculation to the process.
基金Project (No. E9825) supported by the Natural Science Foundation of Heilongjiang Province,China
文摘In order to remove the low turbidity present in surface water, a novel metal-polysilicate coagulant was used to treat the raw water taken from Tanjiang River in Guangdong Province. This study on the effects of Al/Fe molar ratio on the performance of a complex compound formed by polysilicic acid, aluminium and ferric salt (PAFS) showed that PAFS with Al/Fe ratio of 10:3 seemed to have the best coagulation performance in removing turbidity and color. Experimental results showed that under the conditions of polymerization time of 15 d, sedimentation time of 12 min, and pH of 6?8, PAFS with Al/Fe molar ratio of 10:3 had the best coagulation efficiency and lowest residual Al concentration. The turbid- ity decreased from 23.8 NTU to 3.23 NTU and the residual Al concentration was only 0.165 mg/L in the product water. It could be speculated that colloidal impurities and particulate Al were removed by adsorption bridging and electrical neu- tralization of long chain inorganic polymer coagulants.
文摘Objective:To ascertain the level of intestinal parasites vis-a-vis the quality of housing and water supply,and sanitary conditions among the people of Kuraje village in Zamfara state. Methods:The study was cross sectional in nature.Individual households were selected using systematic random sampling methods and pre-tested questionnaires were administered to all the members of each household.Stool samples were collected and processed using standard laboratory procedures.Housing conditions,sources of water and sanitary conditions of the households were also inspected.Results were analysed using Epi Info 2006 model.Results: The prevalence of intestinal parasites was 67.0%(347/519).72.3%(251/347),17.0%(59/347),and 10.7%(37/347) had one,two and three or more parasites,respectively.The associated factors with intestinal parasites were poor housing and sanitary conditions,lack of potable water and illiteracy.The commonest parasites encountered were hookworm(22.0%),Ascaris lumbricoides (18.5%),and Strongyloides stercoralis(15.6%) while the least common was Enterobius vermicularis (1.6%).Others were Giardia lamblia(5.7%),Hymenolepsis nana(5.0%),Trichuris trichiura(8.8%), Entamoeba histolytica(14.4%) and Schistosoma mansoni(8.4%).Conclusions:The infection rate of intestinal parasites in Kuraje village is high.More efforts should be intensified towards improvement in sanitary and housing standards,supply of potable water and institution of a more comprehensive literacy programme for the people of the community.
文摘Following biological treatment, wastewater continues to have endotoxic active materials. However, because there is a trend of potable reuse and because endotoxic active materials potentially have harmful effects on human health, their removal from water is crucial. Lipopolysaccharide endotoxin has hydrophobic groups, and their removal using a coagulation-flocculation alternative is believed to be efficient. Thus, their removal from reclaimed wastewater using the coagulation-flocculation process was assessed. Secondary effluent samples from a wastewater treatment plant located in Sapporo, Japan, were investigated. It was found that this process gave satisfactory results in removing endotoxins, with an optimum removal rate of up to 40.5%. The endotoxin removal was maximized by adjusting the pH at the low range 4 - 5.5, with an aluminum sulfate dose of 80 mg/L. Further increases of the coagulant dose did not improve the removal efficiency. DOC and turbidity removal were at their optimum at higher pH range 5.5 - 6.5. Thus coagulation and flocculation could be considered as the first barrier and should be followed by other treatments to safely reuse reclaimed wastewater.
基金Sponsored by the National Key Research and Development Program of China(Grant No.2016YFC0400707)National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2015ZX07203-007)+1 种基金National Natural Science Foundation of China(Grant No.31601834)Natural Science Foundation of Tianjin(Grant No.14JCYBJC22900)
文摘An accurate chlorine bulk decay model is needed to ensure that potable water meets the microbial and the chemical safeties at the treatment plant and throughout the distribution. Among the mathematical models available,the general second-order chlorine bulk decay model( GBDM) is the most fundamentally sound.Application of the GBDM,however,has been hindered by its numerous fictive parameters and lack of an analytical solution. This theoretical work removes the two obstacles. The GBDM is solved through transformation and integration. The analytical solution provides deep insights into the GBDM and facilitates the parameterization and sensitivity analysis. The background natural organic matter( NOM) is characterized with the probabilistic distribution of functional groups. It reveals that the mean of the function group distribution is correlated with the initial chlorine decay rate coefficient( κ_0). A simple formula is developed to determine κ_0 directly from the initial chlorine decay. The theoretical treatment reduces the fictive parameters to a minimum. For the common lognormal distribution,the GBDM needs only three parameters,well defined as initial chlorine demand X_0,median rate coefficient km,and heterogeneity index σ. For more complicated scenarios,composite distributions are constructed through superposition of individual distributions. A highlighted example is to predict chlorine decay in blends of different waters. With the theoretical and mathematical advancement here,the GBDM can be applied effectively to any reactive background matter in any reaction systems.
文摘Peninsulas are exceptional areas loved to be developed uniquely in most part of the globe. Lekki Peninsulas in Lagos, Nigeria is fast growing, benefitting from similar fortunes such as modern residential suburbs, free trade zone, airport;and tourism are springing up but without adequate potable water for sustainable development. Reconnaissance surveys followed by an In-Depth-Interview were carried out. The commonest sources are sachet, bottled and borehole waters. Sachet and bottled waters are readily available but at unaffordable costs. The most frequently available is borehole, but chemical, physical/organoleptic and microbiological analysis show that the compositions are not within WHO permissible standards. Sustainability is in jeopardy. Individuals, organizations and businesses spend average of 15% of their income on treatments to meet acceptable standards. There are needs to bridge the gap between the residents taking untreated poor water and the few that take WHO standardized waters. A Simple Water Treatment Device is recommended. The device consists of four chambers, two pumping machines, alum and chlorine for treatment. It is equipped with 12 to 13 valves (depending on the position of the chambers);and the entire system is powered by electricity. It will control water borne diseases such as typhoid, schistotomiasis, diarrhea and dysentery, hepatitis, cholera and others;potable water will be available for domestic, recreational and industrial uses;enough for use in the Free Trade Zone and at the forth coming airport;the Eighteen Golf Course will not have challenges of potable water;and forces and military formations within and around the peninsula can rely on the source for every use. It is estimated that the system that can provide average of 100,000 liters of water a day will cost N720,000:00, that is, outside the cost of electricity. The system requires regular maintenance. This device could be applied anywhere.
文摘A comprehensive study was conducted to evaluate a rural community’s efforts to solve its potable water problem. Residents of St. Margaret village has built a rudimentary water storage facility through their community efforts and run a network of water supply to the households of the village. The study analyzed the water quality of the reservoir for physical, chemical and microbiological parameters by using standard water quality measurements and compared it between the wet and the dry seasons. The results indicate that the temperature and the pH were highest in the month of April. The phosphate level was high during the month of November whereas the dissolved oxygen level was lowest during November. The presence of fecal coliforms and other pathogenic microbes such as Salmonella and Shigella suggested that the water bodies are not safe for human consumption. The survey of the households in the village also revealed that health ailments associated with gastrointestinal tract are common among the people using the water for drinking purpose. The community’s effort in finding solution to their potable water problem has been demonstrated in the design and execution of the rudimentary reservoir in the St. Margaret village. Although majority of the inhabitants of the village have only primary-level education, they were able to carry out a major engineering project.
