Drinking Water Quality Research Articles

Sanitary and Chemical Analysis of Drinking Water and Laboratory Control of the Content of Toxic Elements of Pesticides and Mycotoxins in Food Products

Relevance of the study: nutrition is the most important factor in maintaining health, normal growth and development of children and adolescents, preventing a number of diseases, maintaining high performance of the adult population, maintaining active longevity. Drinking water and food are necessary for the existence of humans and all life on Earth. Issues related to increasing responsibility for the effectiveness and objectivity of quality control of drinking water and food products are relevant in guaranteeing their safety for the health of consumers. Objectives of the study: to study the quality of drinking water and the efficiency of the water supply system in Osh in the period from 2020 to 2023; analysis of compliance of drinking water quality with sanitary and chemical standards; development of recommendations for improving the quality of water and the water supply system in Osh. Determination of toxic elements, pesticides and mycotoxins in food products, determination of physicochemical indicators and toxic elements in drinking water, pesticides and mycotoxins in food products was carried out in accordance with regulatory documents of GOST and the maximum permissible concentration. The test results showed the normal and permissible levels of pH, total iron, fluorides, hardness, dry residue, ammonia, nitrates, etc. in water, and the content of aflatoxin B1, the mass concentration of cadmium and lead, hexachlorane, dichlorodiphenyltrichloroethane in food products. For a more in-depth analysis, it is recommended to use additional data on climatic conditions, geological features of the region, as well as the demographic situation in Osh.

Gross Alpha/Beta Radioactivity of Drinking Water and Relationships with Quality Parameters of Water from Alba County, Romania

Drinking-water is considered one of the existing exposure situations to radiation, which involves a level of risk for human health. Thus, its radioactivity is evaluated to keep exposure “as low as reasonably achievable”. Based on monitoring data sets (2017–2023) for six physical-chemical indicators of drinking water quality and total radioactivity expressed by gross alpha activity, gross beta activity and Radon222 content, we evaluated the correlations, relationships, predictors (water source, locality, year), regional variations and potential baseline patterns using statistical analysis and models. The obtained model shows that drinking water sources and localities are factors with significant effect on nitrates concentration and total hardness, ranking sources in the order: well > spring > municipal distribution system; the rank order of drinking water sources based on the concentration of Radon-222 is spring > well > municipal distribution system; locality was found the best predictor for radioactivity; significant correlations were found between gross alpha and gross beta, between gross beta and Radon-222, and between ammonia, nitrates, nitrites and total hardness. The establishment of a baseline pattern for gross alpha activity is a public health goal that can be achieved through performance monitoring of natural radioactivity in water, useful for preparedness in case of a nuclear event

Continuous Monitoring of Monochloramine in Water, and Its Distinction from Free Chlorine and Dichloramine Using a Functionalized Graphene-Based Array of Chemiresistors.

Monochloramine (MCA) is commonly added to drinking water as a disinfectant to prevent pathogen growth. The generation of MCA at the treatment plant requires tight control over both pH and the ratio of free chlorine (FC) to ammonia to avoid forming undesirable byproducts such as dichloramine (DCA) and trichloramine (TCA), which can impart odor and toxicity to the water. Therefore, continuous monitoring of MCA is essential to ensuring drinking water quality. Currently, standard colorimetric methods to measure MCA rely on the use of reagents and are unsuitable for online monitoring. In addition, other oxidants can interfere with MCA measurement. Here, we present a solid-state, reagent-free MCA sensing method using an array of few-layer graphene (FLG) chemiresistors. The array consists of exfoliated FLG chemiresistors functionalized with specific redox-active molecules that have differential responses to MCA, FC, and DCA over a range of concentrations. Chemometric methods were employed to separate the analytes' responses and to generate multivariate calibration for quantification. A minimum of three sensors are required in the array to maintain full functionality. The array has been demonstrated to quantify MCA in buffered and tap water as a low-cost, reagent-free approach to continuous monitoring.

Microbial Quality of Drinking and Utility Water in Tourism Facilities in Antalya

Microbial Quality of Drinking and Utility Water in Tourism Facilities in Antalya

Short Communication: Rotavirus Group A Occurrence in Rural Water Source Samples in a Midwest Region State of Brazil, Comparing Wet and Dry Seasons.

Identified as a potential reference pathogen by the WHO Guidelines for Drinking-Water Quality, Rotavirus (RV) is among the main enteric viruses that cause waterborne diseases. The aim of this study was to identify and correlate the presence of RV in collective and individual water sources of rural communities in the state of Goiás, within the seasons in which the collections were made (rainy and dry seasons). For this, 86 water samples in the dry period and 160 samples in the rainy period were collected. Concentration of water samples, extraction of viral genetic material and molecular tests were performed. When analyzing the presence of RV in the samples, taking into consideration the period studied, RV was found to be more prevalent in the dry season (54.7%) than in the rainy season (20%), showing a strong statistical association with the dry season (p-value < 0.001). The presence of pathogenic microorganisms in water is a public risk issue, enabling the emergence of outbreaks, endemics and epidemics. In the present research, there was an association between the presence of Rotavirus and the dry period of the year when compared to the rainy period.

Assessment of groundwater quality for drinking and irrigation in Dindigul district, southern India: Hydrochemical characterization and spatial analysis

There are many renewable resources, but groundwater is one of the most important. The use of groundwater for various purposes is inevitable in the modern world. This study aimed to investigate the groundwater resources in the Dindigul and Vedasandur taluks of Dindigul district, southern India, for these various uses. About 36 groundwater samples were collected from dug wells and borewells. The samples were analyzed for total dissolved solids, total hardness, and both major and minor ions to determine the water type, ion concentration and suitability for drinking purposes. Analysis reveal that, based on TH and TDS, most wells exhibited hard to very hard with fresh to brackish characteristics. TDS, TH, Mg, Na, and K levels in drinking water exceeded permissible limits in 8 %, 14 %, 14 %, 39 %, and 25 % of samples, respectively. For irrigation purposes, parameters such as sodium adsorption ratio, residual sodium carbonate, electrical conductivity, Kelley’s ratio, magnesium hazard, and permeability index were found to be unsuitable in 36 %, 3 %, 14 %, 69 %, 97 %, and 3 % of the samples, respectively. The Study area shows that 89 % of the samples are fit for drinking purposes. Sodium, bicarbonate and chloride ions were identified as the dominant hydrochemical components in the region. The hydrochemistry varied spatially, with higher concentrations observed primarily in the northwestern parts of the area. Most wells were found suitable for drinking, with the exception of a few in the northwest. The quality of water for agricultural use was generally acceptable. The drinking water quality index indicated that most areas were good for drinking, except those in the northwest. The hydrochemistry of the region appears to be influenced by processes such as evaporation, silicate weathering, and irrigation return flow. Evaporation, along with the weathering of hornblende, biotite, and charnockite rocks played a significant role in the groundwater.

International and domestic experience in standard regulation of bottled drinking water quality

Regulatory control of the quality of bottled drinking water is an important area of protecting health and enhancing quality of life in population, including children. The aim of the study is to conduct a comparative analysis of regulatory measures for the quality of bottled drinking water based on chemical indices, with a view to considering international standards to improve the Russian legal framework in this field. The analysis incorporates foreign regulatory and legal instruments in the area of control and monitoring of the quality of packaged drinking water, such as the Codex Alimentarius and directives of the European Parliament, Council of the European Union, Code of Special Regulations of Food and Drug Administration, ТР ЕАЭС 044/2017 Technical Regulations.Current international and domestic regulations, ensuring bottled water quality, have been analyzed. In spite of the fact that regulatory documents comprise fifty three common indices, over half of the international standard values differ significantly as compared to ТР ЕАЭС 044/2017 Regulations. There are noted advantages of domestic regulations, considering the specific requirements for bottled drinking water for children and the physiological benefits of water. In this study, only the regulation of chemical indices in packaged drinking water has been considered based on 4 regulatory documents. Additionally, the work has not taken into account in detail those indices that are not included in domestic regulations. Conclusion. A comparative analysis of international and national regulations has shown the Russian Federation to have more stringent requirements for the regulatory values of bottled water quality. Taking into account current trends it is necessary to improve and expand constantly the system of regulatory quality control of bottled drinking water by including those indices concentrations of which are regulated by international legislation.

Assessing water quality of kazerun county in southwest Iran: Multi-analytical techniques, deterministic vs. probabilistic water quality index, geospatial analysis, fuzzy C-means clustering, and machine learning

Water quality is critical to human health and the environment, especially in arid and semi-arid regions. Hence, the objectives of this study were to assess drinking water quality, identify critical parameters, investigate spatial patterns, and investigate accurate predictive models for the water quality index (WQI) in the Kazerun county in southwest Iran. To address this issue using deterministic and probabilistic WQI, correlation matrix, fuzzy C-Means (FCM) clustering, geostatistics, and adaptive network-based fuzzy inference system (ANFIS) with FIS generation by fuzzy C-Means (FCM-ANFIS) and sub-clustering (SC-ANFIS).Various software tools, including Excel, MATLAB, Python, and GIS were used to analyze groundwater data collected from 25 sampling sites. Water parameters, including pH, Cl−, SO4−2, EC, NO3−, NO2−, Ca2+, Mg2+, and F−, were examined. The results showed that F− levels were within acceptable limits set by the US EPA, but about one-third of sites posed potential health risks based on WHO guidelines. In one-third of regions, the levels of Mg2+ exceeded the recommended guidelines. In deterministic and probabilistic approaches, water quality was excellent in 68% and 81.3% of sites, respectively. Sobol sensitivity analysis identified SO4−2> Mg2+>Cl− > EC > F− > NO3− as significant WQI variables. Spearman correlation matrix shows substantial positive correlations between WQI and EC, F−, SO4−2, Mg2+, and Cl− were shown by the Spearman correlation matrix. Based on the FCM results, the southeast and central sites (56% of sites) have similar water quality. In comparison, the northern and four central sites (28% of sites) have distinct regional features, and the southern sites (16% of sites) had unique water quality characteristics. Geostatistical analyses showed that pH had the most substantial local clustering, while SO4−2 had significant high-value clustering. Furthermore, hot spot research revealed specific sites with high pH, F−, NO3−, and Cl− levels. The FCM-ANFIS model outperformed the SC-ANFIS model, emphasizing FCM clustering's importance in water quality forecasting accuracy.

Discussion on aesthetic and chemical characteristics of drinking water quality in emergencies

The Standards for drinking water quality(GB 5749-2022), which has taken effect on April 1, 2023, stipulates that limit values of aesthetic and chemical characteristics of drinking water can be temporarily adjusted in emergencies. However, the national standard does not clearly specify the adjusted period and limit values. This study is based on the principle that the human body will not cause acute toxic damage during short-term exposure, considering the acceptability such as chromaticity, smell, and taste in drinking water, referring to the drinking water quality standards of different countries and regions including the World Health Organization, the United States, the European Union, Japan, Australia, etc. We discussed the limited values during emergencies for 21 aesthetic and chemical characteristics from GB 5749-2022 to guaranine the drinking water safety and human health in emergencies.

Socio-Economic Perspectives of Household Water Treatment for Safe Drinking in Nigeria

Access to safe drinking water remains a huge challenge to households in developing countries of which Nigeria is one. This is evident from the numerous cases of water related diseases ravaging the country. The United Nations Children Emergency Fund reports that over 150,000 Nigerians and about 117, 000 under five children, die of water borne diseases annually. Since safe water is gotten from water treatment, the challenges associated with ensuring that water is adequately treated for the households are enormous. Considering that the household is generally the primary source of drinking water for the populace, the socio-economic characteristics of a household plays a key role in determining their access to quality water for drinking. It is based on this that this study seeks to evaluate how household socio-economic characteristics influences a household’s decision to treat its drinking water. The study uses the Binary Logistic regression model to test for the correlates of household water treatment decisions. The data employed in this study is sourced from the Multiple Indicator Cluster survey conducted by UNICEF. A total of 26359 households were selected for the study. The study shows that about 23,495 of the selected households do not treat their water for safe drinking in Nigeria. The result also shows that source of drinking water is a key determining factor in the water treatment decisions of households, as different sources of water were found to have varying degrees of effects on water treatment decisions by households. Some ethnic groups were also observed to have a poor water treatment culture. Also, education of household head and high wealth status increases water treatment.

Perceived and Physical Quality of Drinking Water in Pavlodar and Akmola Rural Regions of Kazakhstan

Water quality in rural areas of developing countries is a notable problem. In this article, drinking water quality from eleven villages in the Pavlodar and the Akmola region of Kazakhstan was analyzed. Questionnaires of village respondents and chemical components of drinking water were analyzed to identify the quality of drinking water. In each of the villages, the chemical content varied depending on the source of drinking water. In the rural Pavlodar region, we observed that some cations and anions exceed the MPC. Respondents’ perceptions of water quality are associated with water sources and physical components. For example, respondents’ satisfaction by inside tap of central water systems’ water was high, the answers of those whose water source was private wells showed more mixed satisfaction levels. The drinking water physical quality indicators are closely related to water mineralization and general hardness. The total microbial count of drinking water has a significant relationship with respondents’ complaints about unpleasant taste, odor, and salinity. The relationship between perceived and physical water quality is a critical aspect of water resource management. By bridging the gap between scientific assessments and public perceptions, we can enhance public health, build trust in water management systems, and promote sustainability of water use.

Prediction of Drinking Water Quality for Effective Public Health Management to Avoid Water Borne Diseases

The issue of water quality failure is a persistent global concern that leads to sickness, toxicity, the spread of diseases, and loss of life in metropolitan areas. Various physical, functional, and ecological factors may affect drinking water quality. These concerns include the incursion of pollutants into water pipes, leakage, the formation of disinfectant waste products, the penetration of chemicals or microbes, and pollution. Water-borne Diseases (WD) have emerged as a significant global public health issue. It is imperative to forecast the quality of drinkable water by utilizing an automated model that provides a preventive strategy that may be created to enhance public health management (PHM). This study forecasted the Drinking Water Quality (DWQ) to promote Public Health Management (PHM) strategies to prevent WD. Convolutional Neural Network (CNN) with Inverse Distance Loaded (IDL) interpolation has been used to forecast DWQ. One hundred five water specimens from the research region underwent thorough examination via physiochemical and microbiological analyses. The tested characteristics were pH, turbidity, temperature, fluoride concentration levels, and bacterial counts (Faecal Coliforms) to prevent WD. The test findings indicated that the CNN-IDL projected 35% of water specimens from the domestic pipeline network had bacteria levels below what the WHO considers acceptable. Also, about 57% of the samples from the home pipeline network met the fluoride reference values set by the WHO. The sanitary assessment rating clearly showed that the lack of appropriate measures to protect against multiple barriers resulted in declining water quality for users. The findings of this research will be valuable to administrators in implementing essential strategies to avoid WD before it significantly impacts public health.

Human health risk and water quality assessment due to fluoride and nitrate around Cauvery River basin, southern India.

Good quality water for human consumption, irrigation, and industrial use is very important. Today, around the world, water is contaminated by natural processes and human activities. This study aimed to evaluate the suitability of groundwater for drinking and irrigation, identifythe source of fluoride and nitrate contamination, and assess thehuman health risks around the Cauvery River basin in southern India. A total of 30 groundwater samples were collected and analyzed for hydrochemical parameters, including EC, TDS, pH, Ca, Mg, Na, K, HCO3, Cl, SO4, NO3, and F-. The majority of groundwater samples in the study area are used for drinking and irrigation. The pH of groundwater in the study area was observed to be dominantly alkaline. The levels of TDS, Ca, Na, K, F, and TH exceeded the permissible limits recommended by BIS and WHO. Fluoride and nitrate levels in groundwater exceeded the permissible limits for drinking purposes in 43% and 50% of the samples, respectively. The excessive concentration of fluoride and nitrate in groundwater could pose serious human health problems. Fluoride and nitrate concentrations in groundwater vary between 0.1 and 2mg/l and 12 and 95mg/l, respectively. Based on the computation of the drinking water quality index, about 73% of groundwater samples were classified asexcellent to good. Health risk was assessed for infants, children, and adults using non-carcinogenic risk indices such as hazard quotients (HQ), hazard indexes (HI), total hazard indices (THI), and carcinogenic risk indices (CR). Infants, children, and adults have different total hazards indexes ranging from 1.508 to 5.733, 1.579 to 6.003, and 0.011 to 0.046, respectively. Health risk assessment results indicatedthat the hazard index and hazard quotient were above the recommended limit of > 1 in most of the samples for infants and children. Non-carcinogenic risk and carcinogenic risks were more likely to affect infants and children rather than adults through ingestion of contaminated water.

Contaminant of Emerging Concerns in Modder River Catchment of Free State: Implication for Environmental Risk and Water Sources Protection

This study was aimed at monitoring the occurrence and potential sources of emerging contaminants in water sources within the Modder River catchment. Selected water quality indicators were analysed by Hanna multi-parameter meters. Emerging contaminants such as acetaminophen, carbamazepine, ibuprofen, atrazine, simazine, metolachlor, terbuthylazine, 17-alpha-ethinyl-estradiol, estradiol, progesterone, and testosterone were analysed by high performance liquid chromatography mass spectrometry. The sources of emerging contaminants were determined by statistical methods such as Pearson correlation and hierarchical cluster analysis. Results showed that all the sampled water sources have some level of questionable drinking water quality and necessitate some amount of treatment to reduce the contamination before consumption, especially DO, EC, and pH. The 17-alpha-ethinyl-estradiol mean values in rivers (7.79 and 31.55 µg/L), dams (1.83 and 6.90 µg/L), and treated drinking water (0.2 and 0.73 µg/L) were the highest in summer and autumn seasons, respectively. Wastewater effluents, domestic sewage, urban surface runoff, agricultural runoff, and illegal dumping were identified as the possible sources of emerging contaminants pollution. Waste management education, proper application of herbicides, and advance wastewater treatment methods were some of the suggested mitigation strategies. The outcomes may be relevant for environmental protection and water sustainability in the catchment.

Hypervirulent Klebsiella pneumoniae with a hypermucoviscosity phenotype challenges strategies of water disinfection for its capsular polysaccharides

Due to the strong pathogenicity of hypervirulent Klebsiella pneumoniae (hvKP), its performance against disinfectants in water should be understood to protect public health and ecological environment. Unfortunately, the disinfectant tolerance of hvKP with a hypermucoviscosity (HMV) phenotype is a critical underexplored area. Here, the tolerance of K. pneumoniae isolates to common disinfectants was evaluated, and its underlying mechanisms were clarified. Results showed that hvKP strains with HMV exhibited remarkable tolerance to triclosan (TCS), sodium hypochlorite (NaClO), and benzalkonium bromide (BB), surpassing that of low-virulent K. pneumoniae (lvKP) and Escherichia coli, which is the microbial indicator of drinking water quality. Ct value of NaClO reached 4.41 mg/L·min to kill 4-log hvKP, while the values were 2.52 and 2.28 mg/L·min to achieve 4-log killing of lvKP and E. coli, respectively. The curing of the virulence plasmid from hvKP strain K2044 revealed that capsular polysaccharide (CPS) synthesis, driven by the virulence plasmids, helped mitigate cell membrane injury and bacterial inactivation under NaClO stress; consequently, it provided a protective advantage to hvKP. Enhancing the antioxidative stress system to reduce ROS production and mitigate oxidative stress caused by NaClO further improved the disinfectant resistance of hvKP strains with HMV. This study emphasized that hvKP strains with HMV posed a considerable challenge to disinfection procedure of water treatment. It also revealed that an improved dosage of NaClO ensures bacteria killing, indicating the optimization of the design of water treatment processes involving disinfection strategies and technical parameters should be considered.

Determination of Shelf Life of Packaged Water in Selected Water Packaging Factories, Ota, Ogun State, Nigeria

Water is critical for human survival. Therefore, its quality and safety are non-negotiable, especially in packaged forms like sachets and bottles. However, when human beings consume unsafe water, they become prone to waterborne diseases which could result in deaths. Therefore, this study investigated the shelf life of packaged water from four selected water packaging factories in Ota, Ogun State, Nigeria, labeled samples A, B, C and D. Selected physicochemical and microbial analyses were carried out on water samples monthly for three months according to American Public Health Association standards, to assess any changes over the three months. Results indicated that while most samples met the World Health Organization (WHO) minimum standards for drinking water quality, still notable variations were observed as the months of analyses progressed. Sachet water samples exhibited more significant reduction in physicochemical and microbial quality compared with bottled water samples. This study concludes that sample A recorded the best results comparatively. Also, shelf life of sachet water is relatively shorter compared with bottled water, with a suggested storage period of three months under typical room and tropical conditions to ensure safety and quality. These findings emphasize the need for more quality control measures, better storage practices and frequent factory monitoring to ensure safety of packaged drinking water. The study recommends that regulatory agencies better enforce existing water packaging guidelines, while packaging factories should also adopt improved packaging and handling processes to enhance shelf life of their products.

Hazard and Health Risk Assessment of Heavy Metals in Non-Alcoholic Beverage Consumed in Abia State, Nigeria

The quality of non-alcoholic beverages consumed in Aba, Abia State, southeastern Nigeria and health risk assessment of heavy metals required periodic evaluation so as to avert potential health hazard. Hence, the objective of this paper as to evaluate the hazard and health risk assessment of heavy metals in non-alcoholic beverages consumed in Abia State, Nigeria using health risk assessment models. Heavy metals concentrations were determined using atomic absorption spectrophotometer (Agilent 280FS AA). The average heavy metal concentrations of non-alcoholic drink samples ranged from 0.040 - 1.132 mg/l in ascending order of Zn &lt; Cd &lt; Co &lt; Cu &lt; Pb &lt;Cr &lt; Mn &lt; Fe respectively. The average concentrations of Mn, Cr, Cd, Fe and Pb exceeded the standard maximum permissible limits for drinking water quality. The values of estimated daily intake for Cd, Fe, Pb, Cr, Mn and Zn were within acceptable provisional tolerable daily intake and safe limits. The hazard quotient (HQ) values for Mn, Cr, Cd, Zn and Fe were within safe limit (&lt; 1.0), except for Co and Pb that had HQ values greater than one in over 37.5 % of the total samples, indicating associated potential chronic health risks. Hazard index of 72.5% of all the non-alcoholic drink samples were above the safe limit (&gt;1.0), signifying potential chronic health risk as a result of combine effects of these heavy metals. The incremental life cancer for Cr, Cd and Pb ranged from 2.59E-05 - 1.79E-03, 1.35E-04 – 2.81E-04 and 3.92E-06 - 3.24E-05 respectively. The incremental life cancer values of Pb were within the recommended safe limit of not greater than 1.0 × 10-4 and has the least likelihood of any potential cancer risks. However, Cd, and Cr had cancer risk values higher than the save limits, indicating potential life cancer health risks in both children and adult population.

P15-03 Immunotoxicity as an endpoint: on the lookout for contaminants of emerging concern for drinking water quality

P15-03 Immunotoxicity as an endpoint: on the lookout for contaminants of emerging concern for drinking water quality

Comprehensive approach integrating water quality index and toxic element analysis for environmental and health risk assessment enhanced by simulation techniques

Due to water shortages and the potential impact of Ethiopia’s new dam on the Nile River, Egypt is seeking new water resources. This study assesses the drinking water quality and associated risks from potentially toxic elements (PTEs) in the Quaternary aquifer (QA) in Beni-Suef, Egypt. Using a comprehensive approach, including PHREEQC geochemical modeling, ionic ratios, multivariate statistical analyses, and the integrated weight water quality index (WQI), the study evaluated the sources of ion contamination and the mixing of Nile water with QA. Various indices, such as the Heavy Metal Pollution Index (HPI), ecological Risk Index (RI), Hazard Quotient (HQ), and Hazard Index (HI), were used to assess ecological and health risks. Monte Carlo simulations provided probabilistic assessments of non-carcinogenic risks for adults and children. GIS tools were used to map risk indices, identifying the most deteriorated locations for sustainable management. The hydrochemical analysis revealed water facies including Na–Cl, Ca–Mg–HCO3, and mixed types, influenced by carbonate dissolution, ion exchange, and silicate weathering. Contamination sources, particularly in the north and south, were linked to agricultural activities, irrigation return flow, municipal waste, and evaporation. The WQI indicated that 10.14% of samples were extremely poor, 21.7% were poor, 26% were medium, and 42% were good to excellent. PTE contamination varied, with HPI values indicating good water quality in the central area in 53.6% of the collected samples (HPI < 30), but contamination in the north and south is high (HPI > 51). Ecological Risk Index values were below the threshold in 100% of samples (RI < 30), confirming water safety regarding PTEs. In comparison, for hazard index (HI) through oral/ingestion, adults exhibited HI values ranging from 0.012 to 2.16, while children showed higher values, ranging from 0.045 to 8.25. However, the hazard index for oral/ingestion exceeded safe limits in the north and south (HI oral > 1), posing non-carcinogenic risks. Monte Carlo simulations revealed significant risks from oral exposure to manganese (HQ oral > 1), particularly in El-Wasta and El-Fashn, necessitating further treatment and management.

Chance-constrained programming for drinking water quality management under fuzziness and randomness

ABSTRACT In this paper, an inexact fuzzy random chance-constrained programming (IFRCCP) model was proposed to deal with the randomness and fuzziness in the optimization of booster cost for the water distribution system (WDS). The IFRCCP model was applied to a WDS to analyze the effects of randomness and fuzziness on the booster costs. The booster cost intervals were obtained under various violation levels and confidence levels. The results indicated that the lower and upper booster costs increased with the confidence levels of the lower limits and decreased with the violation levels of the lower limits for both normal and log-normal distribution fuzzy random variables (FRVs). Moreover, the increased magnitude of lower and upper booster costs under normal distribution FRV is a little less than that under log-normal distribution FRV, while the decreased magnitude of lower and upper booster costs under normal distribution FRV is larger than that under log-normal distribution FRV. The same regulation can be found for the FVR with both triangular and trapezoidal distribution FRVs. With the increase of booster number, the increased magnitude of the lower and upper booster costs decreased for both normal and log-normal distribution FRVs.