Good Quality Of Drinking Water Research Articles

Modeling the Chlorine Series from the Treatment Plant of Drinking Water in Constanta, Romania.

Ensuring good drinking water quality, which does not damage the population's health, should be a priority of decision factors. Therefore, water treatment must be carried out to remove the contaminants. Chlorination is one of the most used treatment procedures. Modeling the free chlorine residual concentration series in the water distribution network provides the water supply managers with a tool for predicting residual chlorine concentration in the networks. With regard to this idea, this article proposes alternative models for the monthly free chlorine residual concentration series collected at the Palas Constanta Water Treatment Plant, in Romania, from January 2013 to December 2018. The forecasts based on the determined models are provided, and the best results are highlighted.

Effect of biological, psychological, and social factors on maternal depressive symptoms in late pregnancy: a cross-sectional study.

Depression commonly occurs during pregnancy and has become a major public health concern. Depression not only affects the individual but also causes adverse consequences for families and children. However, little is known regarding the depression status and its influencing factors in women during late pregnancy in China. This study aimed to assess the prevalence of maternal depressive symptoms in late pregnancy during the coronavirus disease 2019 (COVID-19) pandemic and further explore the effect of biological, psychological, and social factors on depressive symptoms. An institution-based cross-sectional survey was conducted among eligible women in the late pregnancy stage and underwent prenatal examination at Lianyungang Maternal and Child Health Hospital in Jiangsu Province, Eastern China from December 2022 to February 2023. Data regarding depressive symptoms and biological, psychological, and social factors of the pregnant women were collected via a structured questionnaire. Chi-square test, Fisher's exact tests, and binary logistics regression were used to analyze the data. In total, 535 women in the late pregnancy stage were included in this study, 75 (14.0%) of whom exhibited depressive symptoms. A binary logistic regression analysis revealed that pregnant women who were multiparous (OR: 2.420, 95% CI: 1.188-4.932) and had moderate or severe insomnia symptoms (OR: 4.641, 95% CI: 1.787-12.057), anxiety (OR: 8.879, 95% CI: 4.387-17.971), high fear of COVID-19 (OR: 2.555, 95% CI: 1.255-5.199), moderate or severe family dysfunction (OR: 2.256, 95% CI: 1.141-4.461), and poor social support (OR: 2.580, 95% CI: 1.050-6.337) tended to show depressive symptoms. Conversely, pregnant women who received regular prenatal care (OR: 0.481, 95% CI: 0.243-0.951) and had good drinking water quality at home (OR: 0.493, 95% CI: 0.247-0.984) were more likely to avoid developing depressive symptoms. This study found that the prevalence of maternal depressive symptoms during late pregnancy was high and had multiple influencing factors. Thus, screening for depressive symptoms in women in the late pregnancy stage and providing special intervention programs are necessary, especially for those with risk factors.

An evaluation of groundwater quality and its suitability for drinking and irrigation uses under the GIS framework

Abstract This study reported the results of groundwater quality for drinking and irrigation purposes in Kurukshetra district, Haryana, India. Twelve parameters, namely pH, TDS, TH, sodium (Na+), magnesium (Mg2+), calcium (Ca2+), potassium (K+), chloride (Cl−), sulfate (SO42−), bicarbonate (HCO3−), nitrate (NO3−), and fluoride (F−) were evaluated and the Water Quality Index (WQI) was calculated. Based on the WQI, 31.57% and 68.43% of samples fall in excellent and good drinking water quality. The sodium adsorption ratio (SAR: 5.75–33.8), magnesium hazard ratio (MHR: 0.21–0.75), percent sodium (%Na: 31.34–72.84), residual sodium carbonate (RSC: 139–770), potential salinity (PS: 18.5–90), and Kelley Ratio (KR: 0.9–3.13) were calculated. The SAR, %Na, MHR, and KR indicated that most of the groundwater is suitable for irrigation. In addition, the inverse distance weighted (IDW) interpolation method was also employed to determine the spatial distribution of groundwater quality in the form of maps using ArcGIS software. The Pearson correlation matrix has been calculated to analyze the relationship between the water quality parameters. Gibbs plots have shown that evaporation and rock weathering are primary processes responsible for affecting the hydrochemistry of groundwater. Piper plots suggested that maximum groundwater samples are (HCO3−–Na+), (Na+), and (HCO3−) types.

Approaches for estimating mixing time in a water storage tank

AbstractThe mixing performance of a water storage tank is important to ensure good drinking water quality in a distribution system. A tracer study is a commonly used approach for mixing performance evaluation but has limitations, such as limited sampling points and inability to be applied to the full scale at design stage. In practice, mixing time is usually estimated by the tracer curve measured by a probe sensor in a physical tracer study. However, the probe tracer concentration curve can be affected by many factors in the tracer release approach (e.g., instantaneous pouring or quill injecting), such as pouring volume, vertical penetration, and injecting time, making the estimated mixing time inaccurate. Coefficient of variation (CoV) decay curve is an alternative for determining mixing time. In this study, computational fluid dynamics (CFD) models were developed to study mixing in a cylindrical water tank. Mixing times were estimated from both probe tracer curve and CoV decay curve. Results show that the mixing time estimated from a probe tracer curve only represents local mixing, while that estimated from a CoV decay curve is a more appropriate index for global mixing, suggesting that the CoV decay curve should be used for mixing performance analysis in a water tank.

THE INFLUENCE OF POLYHEXAMETHYLENE GUANIDINE SALTS ON THE MICROBIOLOGICAL PARAMETERS OF WATER

The article represent the use of disinfectant which was made based on salts of polyhexamethylene guanidine hydrochloride (PGMG-hydrochloride) and polyhexamethylene guanidine phosphate (PGMG-phosphate) for water disinfection. Water plays one of the most important roles in almost all life processes. Water is a part of the blood, participates in blood circulatory system, delivers nutrients and oxygen to the organs, participates in oxidation reaction, hydrolysis and other reactions of intercellular metabolism, forms an environment to maintain a healthy microflora of the digestive tract, which provides effective breakdown of nutrients by the optimal amount of enzymes.
 Good drinking water quality must to be epidemically safe and free of pathogenic microbes, viruses and other biological inclusions. Also must be harmless in chemical composition, have good organoleptic properties ‒ be transparent, colorless, have no taste or odor.
 Water quality is assessed by total microbial contamination and the amount of bacteria of the Escherichia coli group in 1 cm3 of water, and also by thermostable Escherichia coli (fecal coliforms) in 100 cm3 of water, pathogenic microorganisms and the amount of coli-phages.
 In result of the conducted researches it was found that the use of disinfectant in 0,2 % concentration did not reduce the total microbial pollution of water. In particular, the efficiency of 1, 2 and 3-hour of exposure was 57, 62 and 68 %, respectively.
 After application of disinfectant in 0,3 % concentration the efficiency of its application was for 1 h – 69 %, 2 h – 82 %, 3 h – 100 %.
 It was found that the use of a disinfectant, which was made based on PGMG salts in 0,4 % concentration contributed to reduce the total microbial contamination of water. The efficiency by the 1, 2 and 3 hour of exposure was, respectively, 73, 86 and 100 %.
 Therefore, the use of a disinfectant, containing in its composition PGMG salts, in 0,3% concentration at 3 hours of exposure was more optimal, which contributed to reduce the total microbial contamination of water.

Assessing Impacts of Changes in External Nutrient Loadings on a Temperate Chinese Drinking Water Reservoir

The safety of drinking water is constantly being evaluated. In the last few decades, however, many drinking waters sources in the world, including in China, have undergone serious eutrophication and consequently water quality deterioration due to anthropogenic induced stressors such as elevated external nutrient inputs. In this study, we used the state-of-the-art complex, dynamic, mechanistic model GOTM-FABM-PCLake (a coupled one-dimensional hydrodynamic-lake ecosystem model) to quantitatively assess the impacts of external nutrient loading on the temperate Jihongtan reservoir in Shandong Province, China. Simulated values of all variables targeted in calibration (water temperature, dissolved oxygen, total nitrogen, total phosphorus, and chlorophyll a) agreed well with observations throughout the entire calibration and validation period and generally mimicked seasonal dynamics and inter-annual variations as found in the monitoring data. A series of scenarios, representing changed external nutrient loadings (both increasing and decreasing compared to the current nutrient load), were set up to quantify the effects on the reservoir water quality. Changes relative to the current external nutrient load had a significant effect on the simulated TN and TP concentrations in the reservoir. Our impact assessment indicate that TN will meet the Chinese water quality requirements of the water source (Class III) when the external nitrogen load is reduced by 70%, whereas TP will meet the requirements even if the external phosphorus load is increased by 100% relative to current loads. The model predicts progressively higher summer and autumn phytoplankton biomasses in the scenarios with increasing external phosphorus loading and potential toxic cyanobacteria will become more dominant at the expense of diatoms and other algae. Strict control of the external nutrient loading is therefore needed to maintain good drinking water quality in the reservoir.

A Fuzzy Cognitive Map method for integrated and participatory water governance and indicators affecting drinking water supplies

Drinking water governance is challenging with different perceptions and priorities among stakeholders in different countries. To make provision for drinking water protection in agricultural areas, governance systems need to be mapped for bottlenecks to be identified and solutions highlighted. To address this a system thinking approach was used in an explanatory network analysis of Fuzzy Cognitive Maps (FCM) that were created during face to face interviews with stakeholder representative groups (individuals, policy developers, researchers, and regulators). Two exercises were designed and facilitated to obtain stakeholder maps on A) the water governance framework from stakeholders' own perspective with a ranking of actors in terms of their perceived importance and B) a list of importance factors and how these were connected for the provision of good drinking water quality supplies in agricultural areas. Causal relationships were subsequently drawn around each subject allowing mapping. A graph theory Hierarchy Index (h) approach examined if stakeholder groups preferred top down hierarchical governance or a more inclusive democratic governance approach. Finally, an auto-associative neural network method was deployed on group maps for examination during steady-state conditions for three scenarios to be explored i.e. changing “Farmers knowledge”, “best management practice (BMP) uptake” and “Farmers behaviour and belief” to the highest level of influence and seeing how the system reacted. Results of Exercise A showed that all stakeholder representative groups had a different perception of the water governance framework. Most stakeholder groups had a democratic point of view regarding water governance structures and the ranking and importance of the actors within the framework. Results of Exercise B demonstrated that most of the groups have similar opinions regarding the highest ranked factors affecting drinking water quality and the possible environmental ecological policy options. In this second exercise, only one representative group showed a democratic outlook whereas all others had a hierarchal outlook. Scenario testing of policy options enabled bottlenecks and possible solutions to be identified. By boosting “Farmers behaviour and belief” to the highest possible level, resulted in a large increase in other factors – a scenario where farmers could benefit from the outcome. This would be achieved by enhancing farmers' willingness and intention to participate and implement BMPs. Better results would be achieved if farmers believed in the method and could benefit from the outcome. Also keeping “Farmers knowledge” at the highest point had a positive influence on the other factors. This can be achieved by enhancing farmers training and knowledge transfer by local and national actors. This method is widely applicable and should be considered for more integrated and participatory approaches to drinking water governance.

Measures to reduce pesticides leaching into groundwater-based drinking water resources: An appeal to national and local governments, water boards and farmers

The purpose of this paper is to show that a number of pesticides is found in groundwater and drinking water resources and to define measures that should reduce the pesticide load in groundwater resources for drinking water in the future. Although the pesticide load that enters groundwater bodies in the Netherlands has gradually decreased over the past ten years, good drinking water quality in the future is not guaranteed. Currently, a number of pesticides ise found in groundwater abstracted for the production of drinking water, worldwide. The most frequently found compounds in the Netherlands are the herbicides BAM (2,6-dichlorobenzonitrile), bentazon and mecoprop. In shallow groundwater, the same compounds are generally found as in deeper groundwater that is abstracted for the production of drinking water, mainly bentazon and mecoprop. Additionally, DEET (N,N-Diethyl-meta-toluamide) is frequently found in shallower groundwater.In order to reduce the pesticide load in groundwater resources for drinking water in the future, 43 measures have been inventoried and ranked based on their scores for ‘effectiveness’ and for ‘practicability’. This paper describes both the most effective measures, with high scores on practicability, and those with limitations regarding practicability. These measures are the most relevant with respect to the frequently found compounds that are still authorised, i.e., bentazon, mecoprop and DEET and, to a lesser extent, glyphosate (due to the presence of its metabolite AMPA (aminomethylphosphonic acid) and glyphosate itself) and isoproturon. The implementation of abstraction-specific ‘Drinking Water Protection Files’, including the systematic collection of data about the relevant water abstraction and the sources and activities that can negatively affect water quality, is recommended.

Effect of temperature variations on the travel time of infiltrating water in the Amsterdam Water Supply Dunes (the Netherlands)

Travel time is one of the important criteria in the design of managed aquifer recharge systems for securing good drinking water quality. Traditionally, groundwater travel time has been modelled without considering the effect of temperature. In this study, a cross-sectional heat transport model was constructed for the Amsterdam dune filtration system (in the Netherlands) to analyse the effect of temperature on groundwater travel times. A groundwater flow model, a chloride transport model, and a heat transport model were iteratively calibrated with measured groundwater levels, chloride concentrations, and temperature series in order to improve model calibration and reduce model uncertainty. The coupled flow and heat transport model with temperature-dependent density and viscosity provided more accurate estimation of travel times. The results show that seasonal temperature fluctuations in the source water in the infiltration pond cause temperature variations in the shallow groundwater. Viscosity is more sensitive to temperature changes and has a larger effect on groundwater travel times. Groundwater travel time in the shallow sand aquifer increases from 60 days when computed with the traditional groundwater flow model to 73 days in the winter season and 95 days in the summer season when computed with the coupled model. Longer travel time is beneficial for water quality improvement. Thus, it is important to consider the effect of temperature variations on groundwater travel times for the design and operation of managed aquifer recharge systems.

Prediction and control of nitrate concentrations in groundwater by implementing a model based on GIS and artificial neural networks (ANN)

Groundwater modelling has become a major step for decision support in integrated water resource management, but groundwater models require accurate and spatially distributed data to provide reliable results. Hydrogeological modelling of these data can be implemented with physically based models (i.e. MODFLOW, MT3D…). Other approaches that are simpler to implement may be a good substitute for these numerical approaches. This is the case of probabilistic approaches and especially the statistical approach neural networks. The proposed method (coupling GIS/ANN) is especially suitable for the problem of large-scale and long-term simulation. It has been applied in the spatial prediction of nitrates in the chalk aquifer in Bethune (North of France). This confined chalk aquifer in its northern part provides natural denitrification and ensures a good drinking water quality, while in its southern part this aquifer is facing a high level of nitrate concentrations far above the European Nitrates Directive standard. A good groundwater management of this ecosystems service is therefore of great importance for regional water management. Thus, the spatial distribution of nitrate concentration obtained by GIS/ANN coupling model was compared with the results obtained from the numerical modelling (MT3D) and validated by the real measurements. ANN modelling seems to be more realistic than MT3D modelling both for 2003 and 2004. This is true for both of the nitrate concentrations and their difference. So, ANN modelling’s spatially distributed difference with observed data ranges from − 3.67 to + 1.24 mg/l in 2003 and − 10.8 to + 6.51 mg/l in 2004, whereas for the MT3D model, this difference ranges from − 11.5 to + 17.9 mg/l in 2003 and − 9.91 to + 16.9 mg/l in 2004. The satisfactory results of the ANN model allowed to launch prospective simulations for 2025 under two groundwater recharge scenarios: a deficit year (150 mm/year) and a rainy year (500 mm/year) show an expansion of the exploitable zone ([NO3–] < 50 mg/L) in the case of a rainy year. The results demonstrate the potential of ANN modelling of spatially distributed hydrogeological data for groundwater management of nitrate pollution. From a groundwater management point of view, the GIS/ANN modelling represents an alternative data analysis to obtain fast results using a less tedious method whose results are satisfactory.

English

Access to safe water is a universal need. However, many of the world&rsquo;s population lack access to adequate and safe water. Consumption of contaminated water with viruses, bacteria and parasites causes health risk to the public and the situation is serious in rural areas. So this study is aimed at assessing the bacteriological quality of drinking water at source and point of use among rural Communities of Farta Woreda, North Western, Ethiopia. A descriptive cross sectional study was conducted in March 2014 in 41 rural Kebeles of Farta Woreda. A total of 120 water samples were obtained from protected water sources and household water storage containers and tested for Escherichia coli by using membrane filter methods. The contaminant risk of water sources and household storage containers were assessed by sanitary inspection checklist of World health Organization. Descriptive statistics (proportion and percentage) were used to count the E. coli load and the results were interpreted using World Health Organization (WHO) guidelines for drinking water quality. All household water storage containers and majority 22(91.7%)&nbsp; of the protected wells and 5(83.3%) springs in the study area were not in compliance with WHO recommended values (0 CFU/100 ml of drinking water) for drinking water. Majority 10(41.7%) of protected well, 5(83.3%) protected spring and 42(46.7%) household storage containers had high sanitary risk score for E. coli. The water sources and also household water storage containers were heavily contaminated with E. coli. Source protection strategies, awareness creation on safe water handling practices as well as monitoring are necessary to enhance good drinking water quality. &nbsp; Key words: Drinking water, E-coli, bacteriological quality, rural community, storage container.

Hydraulic optimization and modeling of hydro-cyclone-systems for treatment and purification of any kind of waters

Water is an indispensable resource for many purposes and good drinking water quality is essential for mankind. This article is supposed to show the need for mobile water treatment systems and therefore to give an overview of different mobile drinking water systems and the technologies available for obtaining good water quality. The aim is to develop a simple to operate water treatment system with few processing stages such as multi-cyclone-cartridge and reverse osmosis with energy recuperation, while the focus is set on modeling and optimizing of hydrocyclone systems as the first treatment stage.

Contamination levels of domestic water sources in Maiduguri Metropolis, Borno State, Northeast, Nigeria

The study examines the levels of contamination of domestic water sources in Maiduguri Metropolis area of Borno State based on their physicochemical and bacteriological properties. It was informed by the global concern on good drinking water quality which is an indicator of development level; hence the focus on domestic water sources to ascertain safety as water from unhygienic sources pose serious health challenges. The study dwelt on physicochemical and bacteriological parameters believed to have health implications. Experimental design was adopted, where water samples derived from four different sources i.e. from treated surface water, deep boreholes, wash boreholes and harvested rainwater were tested in the laboratory for pH, total dissolved solids (TDS), total hardness (TH), aluminium (Al), arsenic (As), cadmium (Cd), chromium (Cr), cupper (Cu), cyanide (Cn), lead (Pb), fluoride (Fl) and nitrate (NO3). Also tested were faecal coliform (E. coli) and total coliform counts in the samples. The results showed that levels of physicochemical parameters are within the acceptable limit of WHO mostly in samples from deep boreholes and treated surface water sources. Samples from wash boreholes and harvested rainwater show escalated levels of some of the physicochemical parameters. The two sources also did not yield zero E. coli count. The study concludes that water from wash boreholes and harvested rainwater sources potent health risk. Thorough epidemiological study to determine health implications of drinking water from wash boreholes and harvested rainwater in the study area was offered as recommendation.Keywords: Domestic Water, Contamination, Boreholes, Diseases

Assessment of the Quality of Water in Sulaimaniyah City, Kurdistan Region– Iraq

Good drinking water quality is essential for the well being of all population. The object of this study was to assess the quality of drinking water in the city of Sulaimaniyah in Iraqi Kurdistan. A total of 2342 water samples from various sources providing water to the city collected during 2014 were analyzed for physiochemical and biological parameters using standard methods. Fifty percent of the samples were from, Dukan project after treatment, 26% from Dukan project before treatment, 8% from Sarchinar, 6% from city storage tanks and networks and 10% were brought by citizens from various sources.The total hardness of the city water at source after treatment was 186.3 (95% CI 179.6, 192.8), TDS was 150.6 (95% CI 149.5, 151.7), and PH was 7.74(95% CI 7.36, 8.12). The total hardness, TDS, turbidity and Calcium were considerably higher in Sarchinar than Dukan (231 vs. 161, 242 vs. 147, 2.7 vs. 1.8 and 72.9 vs. 44.5 mg/l respectively), while Sodium and Potassium were higher in Dukan than Sarchinar (3.4 vs. 1.4 and 1.4 vs. 0.08 mg/l respectively). Samples from the two supply lines from filtrated Dukan water project were compared in relation to physic-chemical characteristics and there were no significant differences in any of the parameters except PH, TDS and turbidity which were different. TDS of Dukan 1 project was slightly higher than Dukan 2 (148.9 vs. 145.9 respectively). Similarly turbidity of Dukan 1 was twice that of Dukan 2 (2.4 vs. 1.2). Overall, the parameter values were within standard ranges except Cl1- which was 19.8 (Iraqi standard 10 ppm) and dissolved oxygen which was 9 ppm (Iraqi standard 7-8 ppm). Microbiological results showed that 973 of the samples (91%) had an MPN of zero, 61 (5.7%) had an MPN of 2.2 and 35 (3.3%) had a higher MPN. The mean chlorination level for all samples was 1.12 (SD 0.44) .We can conclude that both Sarchinar and Dukan waters are acceptable for drinking purposes according to the parameters evaluated. We recommend to include monitoring heavy metals like Hg, Pb, Ni, Cr, Cd, Ag in the future; to consolidate the existing reporting system and to included samples from household tap water for analysis.

Ultra-trace nutritional and toxicological elements in Rome and Florence drinking waters determined by Instrumental Neutron Activation Analysis

In order to ascertain water quality for human consumption, the evaluation of trace and ultra-trace elements in drinking waters of two Italian cities, Rome and Florence, is investigated together with the potabilization processes involved and the relative human exposure to the contaminants. Through a multi-elemental detection with no chemical treatment using Instrumental Neutron Activation Analysis and Proton-Induced X-ray Emission the concentration of 40 elements is determined. Basically, the concentrations of the investigated parameters in drinking waters were within the permissible limits of the World Health Organization drinking water quality guidelines and the Water Pollution Control legislation of Italian authorities. The Rome drinking water shows a chemical water composition quite similar to uncontaminated natural water: potentially toxic elements (e.g., Cr, Hg, Ni, and Sb) are present at very low concentrations whereas the levels of nutritionally essential elements are adequate and low levels of I and Se cannot be considered a cause of deficiency diseases. A multivariate statistical approach was used to identify both the origins and correlations among elements and the six different apportionments contributing to the water supply in Rome. For the drinking waters distributed in Florence, the element levels show a sufficiently good situation, except for Al (range 103–267 μg/L) that is present at reasonable concentrations for almost the entire population due to the hard potabilization procedure involving aluminum salts. The values of Metal Index (MI), that helps to quickly evaluate the overall quality of drinking waters, show a good drinking water quality in Rome (Fe is the only element to be considered critical) whereas in Florence the situation is influenced by Al levels. No relevant differences are found among Rome and Florence water composition and other Italian and world potable waters. This study can be considered a useful reference for studies aimed to highlighting toxicological, nutritional and environmental disease patterns.

Occurrence and analysis of pharmaceuticals and their transformation products in drinking water treatment

Surface water and groundwater are the major renewable resources for sustainable drinking water production in Europe and throughout the world. In regions where water is scarce indirect reuse of potable water is an attractive solution to meet water requirements. In regions with sufficient resources from the natural water cycle indirect reuse of potable water also often occurs in densely populated and urban areas. Consumers use, and repeatedly reuse, water in a cycle of drinking water – wastewater treatment – receiving water – drinking water production. Organic micropollutants, for example pharmaceutical compounds, which are not quantitatively eliminated by wastewater treatment and “survive” natural attenuation processes in surface waters, are an issue in relation to the quality of raw water resources and water supplies. Irrespective of any risks, the precautionary principle should apply and micropollutants from wastewater should not be present in drinking water. This is also a question of public acceptance of, and confidence in, good drinking water quality. The route via drinking water can, moreover, be regarded as the most direct way of human exposure to pharmaceutical residues [1]. There are, currently, no statutory maximum contaminant levels for pharmaceutical compounds in drinking water and no regulatory requirement to monitor them. Requirements of analytical methods