Hydrochemical Characterisation and Assessment of the Level of Contamination of Groundwater Collected by Private Waterworks in the Town of Moundou in the South of Chad

Groundwater is the main source of drinking water for large cities in most African countries. In Moundou, for example, the conventional groundwater supply system is failing. To compensate for this state failure, the population is building boreholes and wells, most of which tap the surface water table, generally referred to as the “water table”. The aim of this study is to characterize these waters in order to assess their level of contamination and, by extension, the degree of pollution of the water table. Major elements such as: Chloride (Cl-), Sulfate (SO42-), Nitrate (NO3-), Calcium (Ca2+), magnesium (Mg2+), sodium (Na+) and potassium (K+) were analysed by Liquid Chromatography and the Bicarbonate ion (HCO3-) was determined by the titrimetric method. The methodology applied is based on a combination of hydrochemical techniques and statistical analysis (PCA and CHA). A sampling campaign was carried out during high-water periods. The results of the physico-chemical analyses show mineralization ranging from 7.29 to 3670 μS/cm, with an average of 487.44 μS/cm. The groundwater studied is generally acidic, with a pH ranging from 3.26 to 6.41. Based on their anions, they are classified into four main hydrochemical facies: chloride and sulphate facies, calcium and magnesium facies, sodium and potassium facies and bicarbonate facies. The various correlations between major ions and statistical analyses have enabled us to identify three hydrogeochemical processes involved in water mineralization. The dominant process is silicate hydrolysis, followed by cation exchange, then anthropogenic input, which influences mineralization by polluting the water.

Electrokinetic chemical characteristics of humic and dannic acids effecting on the natural water and its coagulation

Taking streaming current(SC)as the electrokinetic parameter,this paper demon- strated the electrokinetic chemical characteristics of humic and dannic acids(HA and DA)in sus- pensions including turbid water,coagulated water and HA or DA contained water.Accordingly, the studies were carried out for determining the relationship between streaming current and zeta po- tential ζ(expressed by eleetrophoretie mobility EM)in above water conditions.In addition,the mechanisms of HA effecting on streaming current within or after coagulant addition and the elec- trokinetic detection principles for HA or DA were also investigated on experiments and theoretical analysis.The results indicated that the change of SC like ζ presented meaningful information con- cerning the degree for destabilization of a particulate suspension,and HA or DA in water could re- markably decrease the effect of inorganic coagulant upon streaming current,which is in accordance with their influence on coagulation.

Physico-Chemical Quality of Selected Drinking Water Sources in Mbarara Municipality, Uganda

The study assessed the physico-chemical quality of selected drinking water sources (springs, boreholes, shallow wells and rainfall) in Mbarara municipality with respect to World Health Organization (WHO) drinking water guidelines and other guidelines in light of the increased anthropogenic activities in the municipality. A total of 70 water samples were collected from purposively selected boreholes, springs, wells and rainwater in Nyamitanga, Kamukuzi and Kakoba divisions of Mbarara municipality with various human activities. The samples were analysed for physico-chemical parameters: Temperature, pH, Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), Total Dissolved Solids (TDS), Electrical Conductivity (EC) and Total hardness using American Public Health Association (APHA) standard methods. The mean temperature and pH ranged between 18.07 °C - 23.45 °C and 5.74 - 7.54, respectively. The mean DO values were found to be between 4.84 and 12.86 mg/l;whereas mean BOD was within the range of 1.83 - 7.71 mg/l. The mean TDS and EC of the water samples ranged, between 33.40 - 569.20 mg/l and 29.30 - 1139.90 μS/cm respectively. Furthermore, the lowest and highest mean total hardness were 70.00 and 264.00 mg/l, respectively. The recorded mean water temperatures for each of the water sources were above the WHO threshold temperature (15 °C) which makes drinking water palatable. Boreholes in Nyamitanga and Shuhaddea Secondary Schools, spring in Kiswahili, well in Kisenyi and rainwater in Mbarara University of Science and Technology (MUST) had mean pH below the WHO minimum guideline value (6.5) hence acidic. Borehole in Nyamitanga secondary school, spring in Kisenyi, shallow well in Nyamitanga and the rainwater in MUST had mean DO values below the WHO range (10 - 12 mg/l). Borehole in Shuhaddea Secondary School and the well in Kisenyi had average BOD values above the range of European Union guideline values (3 - 6 mg/l). TDS and EC of all the water sources were below the WHO maximum guideline limits of 1000 mg/l and 1500 μs/cm respectively. Total hardness was also below the WHO harmless limit of 1000 mg/l. However rainwater in MUST was moderately soft while the other drinking water sources exhibited moderate to full total hardness. The physicochemical parameters of some of the selected water sources in Mbarara municipality have been compromised mainly by the increased human activities especially croplands, latrines, landfills, transportation, animal and municipal wastes at the vicinity of the water sources. Mbarara municipal council should therefore ensure proper sanitation and water safety plans for these drinking water sources to avoid further contamination from the human activities.

Assessment of Surface Water Quality of King Abdullah Canal, Using Physico-Chemical Characteristics and Water Quality Index, Jordan

The main aim of this research is to evaluate the water quality of King Abdullah Canal (KAC) using the water quality index method (WQI). For this purpose, nine different sampling sites were used in the calculation of WQI during the period of January to December 2012. The samples were analyzed for various physico-chemical parameters such as pH, electrical conductivity, total suspended solids, ions of Sodium, Potassium, Calcium, Magnesium, Fluorite, Chloride, Sulfate, Bicarbonate, and Nitrate in different seasons (winter, spring, summer and autumn). The analyzed results (by WQI method) have been used to suggest models for predicting water quality. The relative weight assigned to each parameter has a range from 1 to 5, based on the important parameters for drinking purposes. The computed WQI for the nine samples has a range from 46.66 to 542.08. The analysis reveals that the water quality status of the study area is varying from excellent to good in the upper part of the canal and from poor to very poor in the lower part of the canal. Comparing with the World Health Organization (WHO) and Jordan Standard (JS), the results indicate that the lower part of the canal is polluted. Therefore, the water is not safe for domestic use and needs further treatment, especially in the lower part of the canal.

Evaluation of nitrate and trace elements concentration in drinking water:Bottled,tap and well

Concentrations of nitrate and trace elements such as arsenic,cadmium,chromium,copper,manganese,nickel,lead,selenium,antimony and mercury in 18 different brands of bottled water were investigated.For comparison,samples of tap and well water from three different places of Tehran were also analyzed.UV/VIS spectrophotometer and Graphite Furnace Atomic Absorption Spectrometer were used for the analysis of nitrate and trace elements,respectively.Results obtained were compared to Iranian,World Health Organization(WHO)and Environmental Protection Agency(EPA)guideline for drinking water.Nitrate concentration in bottled,tap and well water samples were in maximum safe nitrate concentration of Iranian and WHO standards.However,70%of bottled water samples and one sample of tap water were below the standard level proposed by EPA and probably remedial action should be taken.Concentration levels of all analyzed elements investigated in all examined water samples were below the maximum contaminant level prescribed by Iranian,WHO and EPA regulations.

Physico-Chemical and Bacterial Characteristics of Groundwater and Surface Water Quality in the Lagbe Town: Treatment Essays with <i>Moringa oleifera</i>Seeds

The river water and groundwater from Lagbe town in Benin Republic were collected and analyzed for physical, chemical and microbiological parameters. The surface water samples were treated with alum, Moringa oleifera seeds powder and the combination of alum and Moringa oleifera seeds. The jar-test essays were carried out with two water samples at initial turbidities 7.2 NTU and 14.4 NTU. The water samples analyzed are fairly mineralized (conductivity varies between 166 and 687 μS/cm), enough soft and contain the nitrate (104 mg/L for W4 sample). They are greatly polluted by pathogenic microorganisms such as Escherichia coli, Klebsiella, Enterococcus, Vibrio, Serratia. The optimal dosages of Moringa are 96 mg/L and 80 mg/L respectively. We have observed a reduction of 60% of turbidity and a substantial remove of all pathogenic microorganisms after water treatment with Moringa oleifera seeds. For the combination treatment, 93% of initial turbidity and 92% of initial concentration of organic matter in the sample E2 were eliminated. The pH remained almost constant during the treatment.

High-Precision Direct Determination of the ^(87)Sr/^(86)Sr Isotope Ratio of Bottled Sr-Rich Natural Mineral Drinking Water Using MC-ICP-MS

Strontium has four naturally occurring stable isotopes,84Sr,86Sr,87Sr,and 88Sr,with abundances of 0.56,9.87,approximately 7.04,and 82.53 atomic %,respectively.The 87Sr/86Sr isotope ratio is variable due to the addition of radiogenic 87Sr produced by the beta decay of 87Rb with a half-life of 4.88 ± 0.05 Ga.Thus,

Hydrogeochemical Characteristics and Quality Assessment of Surface Water in an Agricultural Area in Equatorial Africa: The Mungo River Basin, South West Cameroon, Central Africa

The Mungo River and its tributaries represent the major sources of water supply for agriculture and drinking purposes for the Douala city and the south western agricultural region of Cameroon. In this study, the surface water hydrochemistry was investigated at 12 locations to determine the hydrochemical and heavy metals characteristics and to assess the suitability for drinking and irrigational purposes. Results of water samples collected along the main channel and tributaries showed that the major ions were dominated by Ca2+ > Na+ > Mg2+ > K+ > NH4+ and > HCO3- > SO42- > Cl- > F- > PO43- , with concentrations varying between 0 to 60 mg/l. Heavy metal concentrations were relatively weak, dominated by Fe > Mn > As > Cd > Zn > Se. The main hydrochemical facies types revealed primarily 52% Ca-Na-HCO3 and 48% Ca-Mg-HCO3. Base on Gibbs diagram and relative ion ratios, the hydrochemical characteristics are derived from weathering of silicate rocks and atmospheric source. The influence of anthropogenic factors including agro-industrial activities on the hydrochemical characteristics was less marked. The chemical composition of the water samples was compared with the drinking water standards and only the concentration of Fe was above the WHO guide limits in a single sample at Passi. The evaluation of the water quality for irrigation showed that 95% of water samples are suitable for irrigation in almost all soil types. According to the water quality index (HPI, HEI and Cd), this water is considered of excellent quality for consumption. The results provide a preliminary database for sustainable management of water resource in the Mungo River basin.

Classification of Various Bottled Mineral Waters Marketed in Djibouti

In this study, nineteen different brands of bottled mineral waters (7 brands local and 12 brands imported) were collected from supermarkets and independent food stores throughout Djibouti. The chemical composition mentioned on the labels of the nineteen bottled mineral waters has made the subject of a first verification by Ionic Balance Error (IBE). It was found out of the nineteen brands selected, 12 brands (2 brands local and 10 brands imported) had acceptable charge balance error. Correlation Analysis (CA), Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were used to analyze the data collected from the labels of bottled water. The obtained results showed that the 12 brands of studied waters can be grouped in 4 distinct classes with similar chemical characteristics. Two local and one imported brands have the same chemical composition but marketed under different names. It was observed that the chemical content local water brands were within the normal range prescribed by both WHO and USEPA except five imported water brands that have concentration values Ca, HCO3, Mg and SO4 beyond acceptable standards. Total hardness values classified most of the studied brands from moderate to very hard water.

Resource utilization of drinking water treatment aluminum sludge in green cementing materials: Hydration characteristics and hydration kinetics

As a byproduct of water treatment,drinking water treatment aluminum sludge(DWTAS)has challenges related to imperfect treatment and disposal,which has caused potential harm to human health and the environment.In this paper,heat treatment DWTAS as a supplement cementitious material was used to prepare a green cementing material.The results show that the 800℃ is considered as the optimum heat treatment temperature for DWTAS.DWTAS-800℃ is fully activated after thermal decomposition to form incompletely crystallized highly activeγ-Al_(2)O_(3) and active SiO_(2).The addition of DWTAS promoted the formation of ettringite and C-(A)-S-H gel,which could make up for the low early compressive strength of cementing materials to a certain extent.When cured for 90 days,the compressive strength of the mortar with 30% DWTAS-800℃ reached 44.86 MPa.The dynamic process was well simulated by Krstulovi′c-Dabi′c hydration kinetics model.This study provided a methodology for the fabrication of environmentally friendly and cost-effective compound cementitiousmaterials and proposed a“waste-to-resource”strategy for the sustainable management of typical solid wastes.

Evaluation of the Physico-Chemical Properties of the Waters on the Litani River Station Quaraoun

Water security is a very important purpose facing the world in the last decay as one of the main consequences related to the risks of climate change. Water quality of Litani River’s at Quaraoun Lake station in Lebanon was evaluated by measuring various physicochemical parameters between 2008 and 2018. Samples were performed and analyzed the first of every month. Different analytical methods were used to determine the values of 11 physico-chemical parameters. Different statistical methods, such as Principal Component Analysis and the Times Series Representation, were applied to the results to evaluate the water characteristics, determine the operation of the ecosystem and study the correlation between the different parameters in the Quaraoun station. Industrial, agricultural and sewage water pollution of the Litani River were demonstrated by the high concentration of sulfate, phosphate and ammonia. High bacterial activity was proved from the high decreasing of the dissolved oxygen. Important correlations between the different parameters and between the parameters of the ecosystem and the weather were proved.

Study on the Characteristics of Pollutants in Surface Water Source Based on Risk Assessment

Supervision of urban water source area and the safety of drinking water is one of the important tasks in China's current environmental protection work. By reviewing screening methods of characteristic pollutants in urban water source area,screening system of pollutants based on the framework of environmental risk is introduced in detail: establish database of pollutants→determine the evaluation purpose→determine testing end and screening standard→assignment calculation→prioritization. At the same time,the application of health risk assessment and technology in the risk assessment of urban water source area is introduced,so as to provide technical support and theoretical basis for management and protection of urban water source area.

Health Risk Assessment for Bromate (BrO₃^–) Traces in Ozonated Indian Bottled Water

For this study, bromide and bromate ions in various commercial brands of Indian bottled water samples were estimated using ion chromatography. The measured mean concentration of bromide and bromate ions in water samples was found to be 28.13 μg/L and 11.17 μg/L respectively. The average level of bromate in Indian bottled water was found to be slightly higher (~ 12%) than the acceptable limits (10 μg/L) recommended by USEPA (US Environmental Protection Agency). Though, kinetically, it is predicted that 62.5% (6.25 μg/L) of bromide in bottled water is needed to convert into bromate upon ozonation to exceed the minimum acceptable limits, but the average formation of bromate determined to be only 26.77% of the predicted concentration. Bromate concentration in bottled water showed a strong correlation with bromide suggesting that its formation in water is very much influenced and controlled by bromide content. The objective of the present study was to determine the BrO3–) content of commercially available different brands of bottled drinking water in India and to estimate the health risks to population due to ingestion. Results of estimated excess cancer risk and chemical toxicity risk to Indian population due to ingestion of bottled water were presented and discussed.

Quality Assessment of Drinking Water in Tanta City, Egypt

The physico-chemical and biological （algal and bacterial） quality of tap water in Tanta City were elucidated. Samples were collected during December 2011, covering all the water plants and the areal extension of the pipe line network in Tanta. Total dissolved solids content classifies water origin into surface water, shallow and deep groundwater. Fe, Mn and hardness in some samples of groundwater origin are obviously exceeding the WHO （World Health Organization） limit. Mostly, green algae are found （31 species）, followed by diatoms （19 species）, then blue-green algae （13 species）. CCA （Canonical Corresponding Analysis） indicates that green algae are strongly correlated with pH, NH4, alkalinity, Mn and Si; diatoms with EC （electric conductivity）, turbidity, Zn and Si and blue green algae with EC and alkalinity. 50% of samples of surface origin, 80% of samples of both deep and shallow groundwater origins crossed WHO and Egyptian guideline in their content of mean TCC （Total Coliform Count）. CCA estimates strong correlations of TCC with temperature, NH4 and PO4; E. coli with EC; heterotrophic bacteria with turbidity and NO3; Salmonella sp. with Si and SO4 and Pseudomonas aeruginosa with Mn. Finally, the water plants treatment may be not effective and pipes serve as a reservoir for pathogenic microorganisms.

Screening of Polymer Additives in Drinking Water Stored in PET Bottles by UHPLC-ESI-IT-TOF MS

In this study, Ultra High Performance Electrospray Ionization Ion Trap Time of Flight Mass Spectrometry （UHPLC-ESI-1T-TOF MS） method is used to screen the polymer additives in drinking water that is stored in Polyethylene Terephthalate （PET） bottles. After directly analyzing the commercially available water samples, 3 polymer additives （chimassorb 81, irgafos 168 and oleamide） were detected. However, after exposure to sunshine for 8 days, two additional polymer additives （antioxidant 2246 and Butylated Hydroxytoluene （BHT）） were detected besides the former three additives.

Suitability of Drinking Water Sources from Nyaruzinga Wetland for Domestic Use in Bushenyi Municipality, Uganda

This study determined the physico-chemical and bacterial quality of raw (bore-hole, springs, wells) and tap water sources from Nyaruzinga wetland for domestic use in Bushenyi Municipality. Forty samples of raw water were randomly collected from Kacuncu, Kyeitembe and Kikuba tributaries of the wetland and 40 samples of tap water generated from the same wetland were randomly drawn from Ishaka, Nyakabirizi and Central divisions of the Municipality. The samples were analyzed for apparent colour (AC), turbidity, electrical conductivity (EC), total hardness, pH, total iron, residual alum, free residual chlorine and faecal coliforms using standard methods and their values compared with standard local UNBS (2008) and international WHO (2011) drinking water quality guidelines. The results showed that the mean pH of the protected spring below Kikuba Hill (5.21);the AC (Pt/Co) of the borehole below Bweranyangi Junior School (17.28) and the surface well below Nyandozo Primary School (157.58) both situated in Kacuncu as well as the free residual chlorine (mg/L) in tap water at Kanyamabona Trading Centre, Ishaka division (0.192) were below the standard values of WHO (pH, 6.0 - 8.0;free residual chlorine, 0.2 - 0.5) and UNBS (AC, <15). The electrical conductivity, EC (μS/cm) and total hardness (mg/L) of all the selected water sources were within the WHO standards (EC, <1500 (raw water), 0 - 300 (tap water);total hardness, <1500 (raw water), <100 (tap water)). The residual alum (mg/L) in all the tap water sources was also within the WHO guideline (<0.2). On the other hand, the turbidity (27.38 NTUs) and total iron content (0.32 mg/L) of the surface well below Nyandozo Primary School were above WHO guidelines of <15 and <0.3 respectively. Furthermore, the mean faecal coliform counts (CFU/100 ml) in the surface well below Nyandozo Primary School (6.90) and the borehole below Bweranyangi Junior School (16.83) including the surface well below Kyeitembe Trading Centre (9.25) were above the WHO standard faecal coliform count (≤3 TCUs). Only the tap water at Kanyamabona Trading Centre recorded mean faecal coliform counts (0.25 TCUs) beyond the WHO standard (0 TCU). Hence the quality of tap water within the municipality tapped from Nyaruzinga wetland was generally better than the raw drinking water sources (borehole, springs, wells) from the same wetland. Thus the use of piped tap water by the urban inhabitants as opposed to raw water sources needs to be promoted to increase access to safe water.

Assessing Levels and Health Risks of Fluoride and Heavy Metal Contamination in Drinking Water

A systematic study was carried out to assess the level of contamination with fluorides and heavy metals in the drinking water of the city of Daloa as well as the risks to the health of consumers. The waters of 11.11% of the sites sampled exceeded the fluoride limit for drinking water with a contamination index (CI) greater than 0. All the waters recorded concentrations of cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn) and lead (Pb) above the recommended values with CI > 0. However, 22.22% of the sites recorded concentrations below the standard for zinc (Zn) with IC < 0. The assessment of adverse effects on human health showed that the chronic daily intake (CDI) of fluorine and metals was less than 1 (CDI < 1) for both adults and children except for Zn where the CDI > 1 for children in 22.22% of drinking water studied. HQs have an average of less than 1 for fluorine and greater than 1 for all metals. Moreover, the danger indices have values greater than 1. The incremental lifetime cancer risk (ILCR) and the total ILCR are above the recommended values. These results showed that the drinking water sampled is of poor quality due to higher levels of heavy metals, which can constitute a danger to human health. Long-term use of one of these poor quality waters can lead to cancer in consumers. It is therefore necessary to treat this water in order to eliminate the metals before using it for drinking. This study can help decision-makers and competent authorities in charge of water management.

Determining the Quality of Mine Gushing and Mixed Water Using Coupled AHP and Fuzzy Comprehensive Evaluation Methods

This study focused on analysis of the chemical characteristics of mine waters. The aim of this study is to correlate the degree of different ionic components in mine water and the influence of their convergence using a combination of the three-scale AHP and fuzzy evaluation methods for the comprehensive evaluation of water quality. Ion chromatography (ICS 1100) has been used to analyze the content of the water sample while portable pH/EC/TDS/Tem- perature meters (SX 811 and SX 813) were used to test physical-chemical parameters. The results of this study show that chemistry of in No.11 gushing mine is dominated by HCO3-Na and HCO3-Ca, and had a pH between 7.1 and 8.00, belonging to neutral or slightly alkaline water. In addition, water were found to have the hardness between 18 mg/L and 542.5 mg/L. Results also show that the TDS of the roof sandstone and goaves water are higher than Cambrian limestone water, while the turbidity of the mixed water is 20 NTU in the sump, again higher than in other samples such as Cambrian limestone water. Total dissolved solids and the total hardness of Cambrian limestone groundwater mainly depend on the content of K+ + Na+, Ca2+, B={b1,b2,…,bj} and SO2-4. Thus, chemical composition changes remarkably after mine water mixing. Results showed that the coal roof sandstone water is class V while that in the sump is class III, and the Cambrian limestone groundwater is class I. In gushing, the quality of water can vary greatly;thus, water from the coal face roof sandstone and the Cambrian limestone should be stored and treated separately before being utilized.

Water Quality of High-Altitude Lakes in the Sagarmatha (Everest) National Park, Nepal

The aim of this research was to analyze physical and chemical characteristics of high altitude lakes (Gokyo lake series, Imja lake, Pyramid lake) of the Sagarmatha National Park, Khumbu region located above 4500 m altitude. The lake water was studied for three years (2008, 2009 and 2010) to compare the annual changes in the parameters. The findings created a database for present status of high land lakes of Nepal, which can be used for the management of lakes as well as to study the impact of tourism on water quality. The lake water quality in general still stands good in terms of standards for drinking water (WHO, Nepal standard) but degradation process has started. Total nitrogen in water samples was lower than the WHO standard but an increase in the nitrate nitrogen has been recorded. Similarly, total phosphorrous quality was also found increased.

A Perspective on Human Exposures to Plastics Additives in Water-Packaging Materials

Plastic and polymer additives (PA) have unique rational advantages for various water and food packaging applications. However, their (bio)chemical natures are recently recognized for their negative human health impacts. The major adverse consequence of these additives in consumer products is in the form of endocrine-disruption related health-downgrades. Such findings still remain underappreciated in most parts globally;part of which could be ascribed to fragmented studies towards better understanding on the occurrence, release and migration, human exposure, epidemiology and risk assessment of PA from packaging materials. In addition there is limited and disconnected dissemination of research findings on PA effects and mitigation measures to society at present. In light of appropriateness of this topic, a trans-disciplinary research agenda is required for addressing exposure routes to PA, human health burden and prevention measures. This perspective article discusses important research questions relating to PA, which try to shed light to a grey scientific area and help increase consumers’ awareness and intervention to such exposures.