Water

2020 ◽  
pp. 235-272
Author(s):  
John Evans
Keyword(s):  
Drinking Water ◽  
Wastewater Treatment ◽  
Water Supply ◽  
Physical Properties ◽  
Reverse Osmosis ◽  
Virtual Water ◽  
Heavy Elements ◽  
Water Supplies ◽  
Ice Caps ◽  
Vapour Density

The physical properties of water provide a framework for many day-to-day experiences: including the energy intrinsic to the melting and boiling of water, and in the increase in vapour density with temperature. The availability of freshwater is sequestered mainly in ice caps and groundwater and most readily acquired water emanates from the rainwater that falls on land. The demands of water for processing (Virtual water) are substantial. Extension fo water supply by desalination of seawater by reverse osmosis is explained. Options for extraction of minerals from seawater are also developed. The challenges posed by heavy elements, pharmaceuticals and plastics on wastewater treatment and drinking water supplies are elaborated

Water Quality and Health

1991 ◽  
Vol 23 (1-3) ◽  
pp. 201-209 ◽  
Author(s):  
W. Kreisel
Keyword(s):  
Water Quality ◽  
Developing Countries ◽  
Drinking Water ◽  
Water Supply ◽  
Human Health ◽  
Pollution Control ◽  
Wastewater Reuse ◽  
Water Supplies ◽  
Minimum Quality Standards ◽  
Quality Guidelines

Water quality can affect human health in various ways: through breeding of vectors, presence of pathogenic protozoa, helminths, bacteria and viruses, or through inorganic and organic chemicals. While traditional concern has been with pathogens and gastro-intestinal diseases, chemical pollutants in drinking-water supplies have in many instances reached proportions which affect human health, especially in cases of chronic exposure. Treatment of drinking-water, often grossly inadequate in developing countries, is the last barrier of health protection, but control at source is more effective for pollution control. Several WHO programmes of the International Drinking-Water Supply and Sanitation Decade have stimulated awareness of the importance of water quality in public water supplies. Three main streams have been followed during the eighties: guidelines for drinking-water quality, guidelines for wastewater reuse and the monitoring of freshwater quality. Following massive investments in the community water supply sector to provide people with adequate quantities of drinking-water, it becomes more and more important to also guarantee minimum quality standards. This has been recognized by many water and health authorities in developing countries and, as a result, WHO cooperates with many of them in establishing water quality laboratories and pollution control programmes.

scholarly journals Environmental Performance of Small-Scale Seawater Reverse Osmosis Plant for Rural Area Water Supply

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 40
Author(s):  
Latifah Abdul Ghani ◽  
Nora’aini Ali ◽  
Ilyanni Syazira Nazaran ◽  
Marlia M. Hanafiah
Keyword(s):  
Drinking Water ◽  
Global Warming ◽  
Water Supply ◽  
Reverse Osmosis ◽  
Resource Scarcity ◽  
Small Scale ◽  
Seawater Desalination ◽  
Seawater Reverse Osmosis ◽  
Desalination Technology ◽  
The Impact

Seawater desalination is an alternative technology to provide safe drinking water and to solve water issues in an area having low water quality and limited drinking water supply. Currently, reverse osmosis (RO) is commonly used in the desalination technology and experiencing significant growth. The aim of this study was to analyze the environmental impacts of the seawater reverse osmosis (SWRO) plant installed in Kampung Pantai Senok, Kelantan, as this plant was the first installed in Malaysia. The software SimaPro 8.5 together with the ReCiPe 2016 database were used as tools to evaluate the life cycle assessment (LCA) of the SWRO plant. The results showed that the impact of global warming (3.90 kg CO2 eq/year) was the highest, followed by terrestrial ecotoxicity (1.62 kg 1,4-DCB/year) and fossil resource scarcity (1.29 kg oil eq/year). The impact of global warming was caused by the natural gas used to generate the electricity, mainly during the RO process. Reducing the environmental impact can be effectively achieved by decreasing the electricity usage for the seawater desalination process. As a suggestion, electricity generation can be overcome by using a high-flux membrane with other suitable renewable energy for the plant such as solar and wind energy.

Microbiological requirements for safe drinking water production at a large river impacted by human wastewater: a scenario analysis

2021 ◽  
Author(s):  
Katalin Demeter ◽  
Julia Derx ◽  
Jürgen Komma ◽  
Juraj Parajka ◽  
Jack Schijven ◽  
...  
Keyword(s):  
Climate Change ◽  
Drinking Water ◽  
Wastewater Treatment ◽  
Population Growth ◽  
Water Supply ◽  
Large River ◽  
Wastewater Management ◽  
Reference Scenario ◽  
Safe Drinking Water

<p><strong>Background</strong>: Rivers are important sources for drinking water supply, however, they are often impacted by wastewater discharges from wastewater treatment plants (WWTP) and combined sewer overflows (CSO). Reduction of the faecal pollution burden is possible through enhanced wastewater treatment or prevention of CSOs. Few methodological efforts have been made so far to investigate how these measures would affect the long-term treatment requirements for microbiologically safe drinking water supply under future changes.</p><p><strong>Objectives</strong>: This study aimed to apply a new integrative approach to decipher the interplay between the effects of future changes and wastewater management measures on the required treatment of river water to produce safe drinking water. We investigated scenarios of climate change and population growth, in combination with different wastewater management scenarios (i.e., no upgrades and upgrades at WWTPs, CSOs, and both). To the best of our knowledge, this is the first study to investigate this interplay. We focussed on the viral index pathogens norovirus and enterovirus and made a cross-comparison with a bacterial and a protozoan reference pathogen (Campylobacter and Cryptosporidium).</p><p><strong>Methods</strong>: We significantly extended QMRAcatch (v1.0 Python), a probabilistic-deterministic model that combines virus fate and transport modelling in the river with quantitative microbial risk assessment (QMRA). To investigate the impact of climatic changes, we used a conceptual semi-distributed hydrological model and regional climate model outputs to simulate river discharges for the period 2035 – 2049. We assumed that population growth leads to a corresponding increase in WWTP discharges. QMRAcatch was successfully calibrated and validated based on a four-year dataset of a human-associated genetic MST marker and enterovirus. The study site was the Danube in Vienna, Austria.</p><p><strong>Results</strong>: In the reference scenario, approx. 98% of the enterovirus and norovirus loads at the study site (median: 10<sup>10</sup> and 10<sup>13</sup> N/d) originated from WWTP effluent, while the remainder was via CSO events. The required log reduction value (LRV) to produce safe drinking water was 6.3 and 8.4 log<sub>10</sub> for enterovirus and norovirus. Future changes in population size, river flows and CSO events did not affect these treatment requirements, and neither did the prevention of CSOs. In contrast, in the scenario of enhanced wastewater treatment, which showed lower LRVs by 2.0 and 1.3 log<sub>10</sub>, climate-change-driven increases in CSO events had a considerable impact on the treatment requirements, as they affected the main pollution source. Preventing CSOs and installing enhanced treatment at the WWTPs together had the most significant positive effect with a reduction of LRVs by 3.9 and 3.8 log<sub>10</sub> compared to the reference scenario.</p><p><strong>Conclusions</strong>: The integrative modelling approach was successfully realised. The simultaneous consideration of source apportionment and concentrations of the reference pathogens were found crucial to understand the interplay among the effects of climate change, population growth and pollution control measures. The approach was demonstrated for a study site representing a large river impacted by WWTP and CSO discharges, but is applicable at other sites to support long term water safety planning.</p>

Estimation of Fluoride Content of Drinking Water in Dharan

2020 ◽  
Vol 3 (1) ◽  
pp. 88-95
Author(s):  
Bandana Koirala ◽  
Surya Raj Niraula ◽  
Anup Ghimire
Keyword(s):  
Drinking Water ◽  
Dental Caries ◽  
Water Supply ◽  
Optimal Level ◽  
Fluoride Content ◽  
Water Supplies ◽  
Effective Measure ◽  
Guideline Value ◽  
Guideline Values ◽  
Significant Difference

Introduction: Fluoride when present in drinking water at optimal level has been shown to promote oral health by preventing tooth decay. Dental caries represents a health problem that impacts on the medical, functional, nutritional and psychological status of patients in all the age groups. Fluoridation of public water supply is a safe, economical and effective measure to prevent dental caries. Objective: To estimate the level of fluoride present in drinking water supplies in all the wards of Dharan and to compare the fluoride concentration of its different water supply sources. Methods: One hundred water samples were collected from the various sources (ground water and surface water) and its different reservoirs along with random samples of 2-7 from all the wards of Dharan. The samples were then taken to the SEAM-N-MMA laboratory, Biratnagar to be tested for fluoride using the photometric method. Microsoft excel for data entry and SPSS 11.5 version for analysis were used. Significance of the variables was examined by Chi-square test. Results: The results of this study showed that in 96% of the samples taken, fluoride level was below the optimal. Only few samples met the lower range guideline value of Nepal (0.5 mg/l). Also, there was significant difference (p< 0.002) between the surface and consumer level fluoride. Conclusion: The fluoride content in drinking water supplies of Dharan was found to be below optimal level as per the national and WHO guideline values.

scholarly journals Natural fluoride levels from public water supplies in Piauí State, Brazil

2009 ◽  
Vol 14 (6) ◽  
pp. 2215-2220 ◽  
Author(s):  
Josiene Saibrosa da Silva ◽  
Wallesk Gomes Moreno ◽  
Franklin Delano Soares Forte ◽  
Fábio Correia Sampaio
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Urban Areas ◽  
Urban Population ◽  
Dental Fluorosis ◽  
Fluoride Concentration ◽  
Public Water Supply ◽  
Water Supplies ◽  
Two Samples ◽  
High Prevalence

The aim of this work was to determine the natural fluoride concentrations in public water supplies in Piauí State, Brazil, in order to identify cities in risk for high prevalence of dental fluorosis. For each city, two samples of drinking water were collected in the urban area: one from the main public water supply and another from a public or residential tap from the same source. Fluoride analyses were carried out in duplicate using a specific ion electrode and TISAB II. From a total of 222 cities in Piauí, 164 (73.8%) samples were analyzed. Urban population in these towns corresponds to 92.5% of the whole state with an estimated population of 1,654,563 inhabitants from the total urban population (1,788,590 inhabitants). A total of 151 cities showed low fluoride levels (<0.30 mg/L) and 13 were just below optimum fluoride concentration in the drinking water (0.31-0.59 mg/L). High natural fluoride concentration above 0.81 mg/L was not observed in any of the surveyed cities. As a conclusion, most of the cities in Piauí have low fluoride concentration in the drinking water. The risk for a high prevalence of dental fluorosis in these urban areas due to natural fluoride in the water supplies is very unlikely. Thus, surveys about the dental fluorosis prevalence in Piauí should be related with data about the consumption of fluoridated dentifrices and other fluoride sources.

Management of the Occoquan River basin: a 20-year case history

1995 ◽  
Vol 32 (5-6) ◽  
pp. 235-243 ◽  
Author(s):  
C. W. Randall ◽  
T. J. Grizzard
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Drinking Water ◽  
Wastewater Treatment ◽  
Water Supply ◽  
Land Use Changes ◽  
Treatment Plant ◽  
Water Reservoir ◽  
Land Use Management ◽  
Early Results

The high dam on the Occoquan River of Northern Virginia, United States of America, was constructed in 1957, forming a drinking water reservoir with a capacity of 37.1 × 106m3 formed by drainage from a 1 460 km2 watershed, and providing a safe yield of 189 251 m3 per day. Deteriorating water quality in the late 1960s led to a special “policy” for the watershed, designed to preserve the reservoir as a drinking water supply. Key provisions of the policy mandated replacement of the watershed's 11 publicly owned wastewater treatment works with a single advanced wastewater treatment plant (AWT), and establishment of the Occoquan Watershed Monitoring Programme. Early results from the programme established non-point nutrient pollution as a major cause of water quality deterioration and resulted in the implementation of non-point pollution controls throughout the watershed during the late 1970s. The AWT plant went on-line in July 1978. Continuous monitoring since 1973 has demonstrated both the necessity and the effectiveness of point and non-point nutrient controls for the preservation of the reservoir's water quality. The AWT plant provides excellent removal of organics and phosphorus, plus complete nitrification. The nitrates are discharged to the receiving stream to enhance conditions in the reservoir. Control policies include land-use management for the preservation of this essential water supply for 750 000 people in the Washington, D.C. suburbs. Land-use management decisions are based on the results obtained with a watershed-reservoir linked computer model which predicts water quality changes resulting from land-use changes.

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