Applied Water Science (v.8, #2)

Virological and bacteriological quality of drinking water in Ethiopia by Tesfaye Legesse Bedada; Walelign Dessie Mezemir; Firehiwot Abera Dera; Waktole Gobena Sima; Samson Girma Gebre; Redwan Muzeyin Edicho; Almaz Gonfa Biegna; Dejenie Shiferaw Teklu; Kassu Desta Tullu (1-6).
Since unsafe water is responsible for many illness, deaths, and economic failure, water quality monitoring is essential. A cross-sectional study was conducted on 218 drinking waters samples collected between February and June 2016 to assess water quality using phages by the help of CB390 E. coli host, plaque assay; multiple tube fermentation for coliforms and pour plate for heterotrophic bacteria at Ethiopian Public Health Institute. Heterotrophic plate count greater than 100 cfu/ml was noted in 41 samples and detections of total and thermotolerant coliforms and E. coli in 38, 24, and 10 samples, respectively, and no phages detection in chlorinated waters. While heterotrophic plate count greater than 100 cfu/ml was observed in 100 samples and detections of total and thermotolerant coliforms, E. coli, and phages in 75, 60, 42, and 5 samples, respectively, for untreated waters. The majority of the waters contained indicators above standard limits. This indicates that the sources are contaminated and they are potential threats for health. Hence, regular water monitoring should be a priority agenda.
Keywords: Indicators; Drinking water; Coliforms; Coliphage

Globally, salinization affects between 100 and 1000 billion m3 a−1 of irrigation water. The discovery that zero valent iron (ZVI, Fe0) could be used to desalinate water (using intra-particle catalysis in a diffusion environment) raises the possibility that large-scale in situ desalination of aquifers could be undertaken to support agriculture. ZVI desalination removes NaCl by an adsorption–desorption process in a multi-stage cross-coupled catalytic process. This study considers the potential application of two ZVI desalination catalyst types for in situ aquifer desalination. The feasibility of using ZVI catalysts when placed in situ within an aquifer to produce 100 m3 d−1 of partially desalinated water from a saline aquifer is considered.
Keywords: Zero valent iron (ZVI); Irrigation; Aquifer; Catalyst; Desalination

Treatment of landfill leachate wastewater by electrocoagulation process using an aluminium electrode was investigated in a batch electrochemical cell reactor. Response surface methodology based on central composite design was used to optimize the operating parameters for the removal of % color and % total organic carbon (TOC) together with power consumption from landfill leachate. Effects of three important independent parameters such as current density (X 1), inter-electrode distance (X 2) and solution pH (X 3) of the landfill leachate sample on the % color and % TOC removal with power consumption were investigated. A quadratic model was used to predict the % color and % TOC removal with power consumption in different experimental conditions. The significance of each independent variable was calculated by analysis of variance. In order to achieve the maximum % color and % TOC removal with minimum of power consumption, the optimum conditions were about current density (X 1)—5.25 A/dm2, inter-electrode distance (X 2)—1 cm and initial solution of effluent pH (X 3)—7.83, with the yield of color removal of 74.57%, and TOC removal of 51.75% with the power consumption of 14.80 kWh/m3. Electrocoagulation process could be applied to remove pollutants from industrial effluents and wastewater.
Keywords: Electrocoagulation; Landfill leachate; Color and TOC removal; Power consumption; Central composite design

Cadmium is one of the most hazardous heavy metal concerning human health and aquatic pollution. The removal of cadmium through biosorption is a feasible option for restoration of the ecosystem health of the contaminated freshwater ecosystems. In compliance with this proposition and considering the efficiency of calcium carbonate as biosorbent, the shell dust of the economically important snail Bellamya bengalensis was tested for the removal of cadmium from aqueous medium. Following use of the flesh as a cheap source of protein, the shells of B. bengalensis made up of CaCO3 are discarded as aquaculture waste. The biosorption was assessed through batch sorption studies along with studies to characterize the morphology and surface structures of waste shell dust. The data on the biosorption were subjected to the artificial neural network (ANN) model for optimization of the process. The biosorption process changed as functions of pH of the solution, concentration of heavy metal, biomass of the adsorbent and time of exposure. The kinetic process was well represented by pseudo second order (R 2 = 0.998), and Langmuir equilibrium (R 2 = 0.995) had better fits in the equilibrium process with 30.33 mg g−1 of maximum sorption capacity. The regression equation (R 2 = 0.948) in the ANN model supports predicted values of Cd removal satisfactorily. The normalized importance analysis in ANN predicts Cd2+ concentration, and pH has the most influence in removal than biomass dose and time. The SEM and EDX studies show clear peaks for Cd confirming the biosorption process while the FTIR study depicts the main functional groups (–OH, C–H, C=O, C=C) responsible for the biosorption process. The study indicated that the waste shell dust can be used as an efficient, low cost, environment friendly, sustainable adsorbent for the removal of cadmium from aqueous solution.
Keywords: Cadmium; Shell; Valorization; Kinetics; ANN

Lucknow metropolitan city is one of the most populated cities of India, which have been facing many problems such as chaotic urbanization, overpopulation, water scarcity, waterlogging, etc., among these water scarcity is one of the important problem. Rain water harvesting is a futuristic tool for mitigation of water scarcity problem through conservation and storage of rain water. This rain water can be used for all purposes by human beings, thus it is necessary to check the chemistry of rain water. The rain water samples were collected from the five zones of Lucknow city. For the comparative study, water samples have been collected from two different dates first from first rainfall and second after 3 days of interval in the second rainfall. The heavy metal concentrations were found in both first and second rainfall water samples in all zones of Lucknow city. The concentration of chromium, cadmium and lead were found to be sufficiently high in several samples. These heavy metals show the concentration above the permissible limit as set by WHO, which can cause various adverse health impacts.
Keywords: Water scarcity; Rain water harvesting; Heavy metals

Flood susceptibility analysis through remote sensing, GIS and frequency ratio model by Sailesh Samanta; Dilip Kumar Pal; Babita Palsamanta (1-14).
Papua New Guinea (PNG) is saddled with frequent natural disasters like earthquake, volcanic eruption, landslide, drought, flood etc. Flood, as a hydrological disaster to humankind’s niche brings about a powerful and often sudden, pernicious change in the surface distribution of water on land, while the benevolence of flood manifests in restoring the health of the thalweg from excessive siltation by redistributing the fertile sediments on the riverine floodplains. In respect to social, economic and environmental perspective, flood is one of the most devastating disasters in PNG. This research was conducted to investigate the usefulness of remote sensing, geographic information system and the frequency ratio (FR) for flood susceptibility mapping. FR model was used to handle different independent variables via weighted-based bivariate probability values to generate a plausible flood susceptibility map. This study was conducted in the Markham riverine precinct under Morobe province in PNG. A historical flood inventory database of PNG resource information system (PNGRIS) was used to generate 143 flood locations based on “create fishnet” analysis. 100 (70%) flood sample locations were selected randomly for model building. Ten independent variables, namely land use/land cover, elevation, slope, topographic wetness index, surface runoff, landform, lithology, distance from the main river, soil texture and soil drainage were used into the FR model for flood vulnerability analysis. Finally, the database was developed for areas vulnerable to flood. The result demonstrated a span of FR values ranging from 2.66 (least flood prone) to 19.02 (most flood prone) for the study area. The developed database was reclassified into five (5) flood vulnerability zones segmenting on the FR values, namely very low (less that 5.0), low (5.0–7.5), moderate (7.5–10.0), high (10.0–12.5) and very high susceptibility (more than 12.5). The result indicated that about 19.4% land area as ‘very high’ and 35.8% as ‘high’ flood vulnerable class. The FR model output was validated with remaining 43 (30%) flood points, where 42 points were marked as correct predictions which evinced an accuracy of 97.7% in prediction. A total of 137292 people are living in those vulnerable zones. The flood susceptibility analysis using this model will be very useful and also an efficient tool to the local government administrators, researchers and planners for devising flood mitigation plans.
Keywords: Remote sensing; GIS; Flood vulnerability analysis; Frequency ratio; Markham river

Spatial analysis of water quality impact assessment of highway projects in mountainous areas remains largely unexplored. A methodology is presented here for Spatial Water Quality Impact Assessment (SWQIA) due to highway-broadening-induced vehicular traffic change in the East district of Sikkim. Pollution load of the highway runoff was estimated using an Average Annual Daily Traffic-Based Empirical model in combination with mass balance model to predict pollution in the rivers within the study area. Spatial interpolation and overlay analysis were used for impact mapping. Analytic Hierarchy Process-Based Water Quality Status Index was used to prepare a composite impact map. Model validation criteria, cross-validation criteria, and spatial explicit sensitivity analysis show that the SWQIA model is robust. The study shows that vehicular traffic is a significant contributor to water pollution in the study area. The model is catering specifically to impact analysis of the concerned project. It can be an aid for decision support system for the project stakeholders. The applicability of SWQIA model needs to be explored and validated in the context of a larger set of water quality parameters and project scenarios at a greater spatial scale.
Keywords: Analytic hierarchy process; Environmental impact assessment; Geographic information systems; Sensitivity analysis; Water pollution; Highway

Removal of pathogenic bacteria from sewage-treated effluent and biosolids for agricultural purposes by A. A. Al-Gheethi; A. N. Efaq; J. D. Bala; I Norli; M. O. Abdel-Monem; M. O. Ab. Kadir (1-25).
The reuse of treated sewage for irrigation is considered as an important alternative water source in the new water management strategy of the countries that face a severe deficiency of water resources such as the Middle East countries. The organic material and fertilizing elements contained in biosolids are essential for maintaining soil fertility. However, both treated sewage and biosolids contain a large diversity of pathogens that would be transmitted to the environment and infect human directly or indirectly. Therefore, those pathogens should be reduced from the treated sewage and biosolids before the reuse in the agriculture. This paper reviews the considerations for reuse of treated sewage and biosolids in agriculture and further treatments used for reduction of pathogenic bacteria. The treatment methods used for the reduction of pathogens in these wastes have reviewed. It appeared that the main concern associated with the reduction of pathogenic bacteria lies in their ability to regrow in the treated sewage and biosolids. Therefore, the effective treatment method is that it has the potential to destruct pathogens cells and remove the nutrients to prevent the regrowth or recontamination from the surrounded environment. The removal of nutrients might be applicable in the sewage but not in the biosolids due to high nutrient contents. However, the reduction of health risk in the biosolids might be carried out by regulating the biosolid utilization and selecting the plant species grown in the fertilized soil with biosolids.
Keywords: Treated sewage; Biosolids; Pathogenic bacteria; Reuse; Treatment technology; Pathogen growth potential

Effectiveness of groundwater governance structures and institutions in Tanzania by J. L. Gudaga; S. J. Kabote; A. K. P. R. Tarimo; D. B. Mosha; J. J. Kashaigili (1-14).
This paper examines effectiveness of groundwater governance structures and institutions in Mbarali District, Mbeya Region. The paper adopts exploratory sequential research design to collect quantitative and qualitative data. A random sample of 90 groundwater users with 50% women was involved in the survey. Descriptive statistics, Kruskal–Wallis H test and Mann–Whitney U test were used to compare the differences in responses between groups, while qualitative data were subjected to content analysis. The results show that the Village Councils and Community Water Supply Organizations (COWSOs) were effective in governing groundwater. The results also show statistical significant difference on the overall extent of effectiveness of the Village Councils in governing groundwater between villages (P = 0.0001), yet there was no significant difference (P > 0.05) between male and female responses on the effectiveness of Village Councils, village water committees and COWSOs. The Mann–Whitney U test showed statistical significant difference between male and female responses on effectiveness of formal and informal institutions (P =  0.0001), such that informal institutions were effective relative to formal institutions. The Kruskal–Wallis H test also showed statistical significant difference (P ≤ 0.05) on the extent of effectiveness of formal institutions, norms and values between low, medium and high categories. The paper concludes that COWSOs were more effective in governing groundwater than other groundwater governance structures. Similarly, norms and values were more effective than formal institutions. The paper recommends sensitization and awareness creation on formal institutions so that they can influence water users’ behaviour to govern groundwater.
Keywords: Groundwater; Governance; Structures; Formal institutions; Informal institutions; Mbarali district; Tanzania

Hydrochemistry, water quality and land use signatures in an ephemeral tidal river: implications in water management in the southwestern coastal region of Bangladesh by Kushal Roy; Md. Rezaul Karim; Farjana Akter; Md. Safiqul Islam; Kousik Ahmed; Masudur Rahman; Dilip Kumar Datta; M. Shah Alam Khan (1-16).
Despite its complexity and importance in managing water resources in populous deltas, especially in tidal areas, literatures on tidal rivers and their land use linkage in connection to water quality and pollution are rare. Such information is of prior need for Integrated Water Resource Management in water scarce and climate change vulnerable regions, such as the southwestern coast of Bangladesh. Using water quality indices and multivariate analysis, we present here the land use signatures of a dying tidal river due to anthropogenic perturbation. Correlation matrix, hierarchical cluster analysis, factor analysis, and bio-geo-chemical fingerprints were used to quantify the hydro-chemical and anthropogenic processes and identify factors influencing the ionic concentrations. The results show remarkable spatial and temporal variations (p < 0.05) in water quality parameters. The lowest solute concentrations are observed at the mid reach of the stream where the agricultural and urban wastewater mix. Agricultural sites show higher concentration of DO, Na+ and K+ reflecting the effects of tidal spill-over and shrimp wastewater effluents nearby. Higher level of Salinity, EC, Cl, HCO3 , NO3 , PO4 3− and TSS characterize the urban sites indicating a signature of land use dominated by direct discharge of household organic waste into the waters. The spatial variation in overall water quality suggests a periodic enhancement of quality especially for irrigation and non-drinking purposes during monsoon and post-monsoon, indicating significant influence of amount of rainfall in the basin. We recommend that, given the recent trend of increasing precipitation and ground water table decrease, such dying tidal river basins may serve as excellent surface water reservoir to supplement quality water supply to the region.
Keywords: Land use signature; Ephemeral tidal river; Water quality; Hierarchical cluster analysis (HCA); Bio-geo-chemical fingerprint

Contamination of drinking water due to fluoride is a severe health hazard problem. Excess of fluoride (> 1.5 mg/L) in drinking water is harmful to human health. Various treatment technologies for removing fluoride from groundwater have been investigated. The present study showed that the leaves of Moringa oleifera, a herbal plant is an effective adsorbent for the removal of fluoride from aqueous solution. Acid treated Moringa oleifera leaves powder showed good adsorption capacity than alkali treated Moringa oleifera leaves powder. Batch sorptive defluoridation was conducted under the variable experimental condition such as pH, contact time, adsorbent dose and initial fluoride ion concentration. Maximum defluoridation was achieved at pH 1. The percentage of fluoride removal increases with adsorbent dose. The equilibrium sorption data were fitted into Langmuir, Freundlich and Temkin isotherms. Of the three adsorption isotherms, the R 2 value of Langmuir isotherm model was the highest. The maximum monolayer coverage (Q max) from Langmuir isotherm model was determined to be 1.1441 mg/g, the separation factor indicating a favorable sorption experiment is 0.035. It was also discovered that the adsorption did not conform to the Freundlich adsorption isotherm. The heat of sorption process was estimated from Temkin Isotherm model to be − 0.042 J/mol which vividly proved that the adsorption experiment followed a physical process.
Keywords: Adsorption; Fluoride; Freundlich isotherm; Langmuir isotherm; Moringa oleifera ; Temkin isotherm

Regarding the dramatic increase of water additional resource administration in numerous drilling industries’ operational performances and oil/gas extractions, water supply plays a significant role in their performances as efficient as optimum operations, in respect of the way, this utilization is often invisible to the public eye. The necessity of water in a wide variety of drilling operation due to its vast applicant in several functions is widely reported in the literature that has been required to remain these procedures plateau. The objective of this comprehensive study is to conduct an investigation into the studied field and analyze the assessment of necessary water and produced water which is provided in the surface for reinjection procedures in the hydraulic fracturing and water injectivity; in respect of the way, petroleum and drilling industries will push themselves into limits to find suitable water sources from a local source to encapsulate their economic prosperities and virtually eliminate extra expenditures. In comparison to other industries and consumers, oil and gas development is not a significant water consumer, and its water demands can exert profound impacts on local water resources, and this is why it imposes particular challenges among water users in a vast majority of fields and areas in times of drought. Moreover, water has become an increasingly scarce and costly commodity over the past decades, and operators are being beneficially noted that awareness of recycling and reusing phenomenon that has treated effluent is both costs competent and socially responsible. Consequently, energy, environmental situation, and economic prosperity considerations should be analytically and preferably investigated to cover every eventuality and each possibility of disposal and water reuse options.
Keywords: Drilling industries; Water reuse; Economic prosperity; Water treatment; Reuse options

This study explores the capacity of synthesized Fe2O3 nanoparticles (NPs) under sunlight for the degradation of dissolved organic matter (DOM) from synthetic (Procion blue dye) solution as well as from textile wastewater (TWW). Fe2O3 NPs were properly synthesized and confirmed by UV absorbance, FTIR spectra and SEM image analysis. Photocatalytic degradation of DOM from TWW and synthetic solution was performed by catalyst Fe2O3 NPs (5 mg/L) in the presence of solar irradiation (up to 40 h). The DOM degradation of the TWW and synthetic solution has been analyzed by fluorescence 3D excitation emission matrix (3D EEM). Synergistic effect was expected and it was found that the rate of decrease of fluorescence intensity increased with time. Within 20 h, for the synthetic solution, reduction of fluorescence intensity (80%) reaches an equilibrium. In contrast, the rate of decrease in the fluorescence intensity is highest (91%) in 40 h of irradiation for TWW. This reduction of fluorescence intensity indicates the degradation of DOM and can be expressed well by second-order model kinetics. Reduction of TOC, BOD5 and COD load again validated the degradation of DOM from TWW by catalyst Fe2O3 NPs-induced solar irradiation. We applied the treated wastewater on the plant to observe the reusability of the treated TWW, and the morphological data analysis of the plant demonstrates that the catalyst Fe2O3 NPs-induced solar-irradiated wastewater exhibits less adverse impact on plant morphology.
Keywords: Iron nanoparticle; Textile wastewater; 3D EEM

Separation of acid blue 25 from aqueous solution using water lettuce and agro-wastes by batch adsorption studies by Muhammad Raziq Rahimi Kooh; Muhammad Khairud Dahri; Linda B. L. Lim; Lee Hoon Lim; Chin Mei Chan (1-10).
Three plant-based materials, namely water lettuce (WL), tarap peel (TP) and cempedak peel (CP), were used to investigate their potentials as adsorbents using acid blue 25 (AB25) dye as a model for acidic dye. The adsorbents were characterised using Fourier transform infrared spectroscopy, X-ray fluorescence and scanning electron microscope. Batch experiments involving parameters such as pH, temperature, contact time, and initial dye concentration were done to investigate the optimal conditions for the adsorption of AB25 onto the adsorbents. Thermodynamics study showed that the uptake of AB25 by the three adsorbents was feasible and endothermic in nature. Both the Langmuir and Freundlich isotherm models can be used to describe the adsorption process of AB25 onto WL and CP while pseudo-second-order fitted the kinetics data, suggesting that chemisorptions were majorly involved. The use of 0.1 M of NaOH showed the best results in regenerating of the WL, TP and CP’s adsorption ability after AB25 treatment.
Keywords: Acid blue 25; Adsorption; Artocarpus odoratissimus ; Artocarpus integer ; Pistia stratiotes ; Water remediation

The present study was carried out to assess the groundwater quality for drinking purposes in the Quaternary Unconsolidated Sedimentary Basin of the North Chengdu Plain, China. Six groups of water samples (S1, S2, S3, S4, S5, and S6) are selected in the study area. These samples were analyzed for 19 different physicochemical water quality parameters to assess groundwater quality. The physicochemical parameters of groundwater were compared with China’s Quality Standards for Groundwater (GB/T14848-93). Interpretation of physicochemical data revealed that groundwater in the basin was slightly alkaline. Total hardness and total dissolved solid values show that the investigated water is classified as very hard and fresh water, respectively. The sustainability of groundwater for drinking purposes was assessed based on the fuzzy mathematics evaluation (FME) method. The results of the assessment were classified into five groups based on their relative suitability for portable use (grade I = most suitable to grade V = least suitable), according to (GB/T 14848-93). The assessment results reveal that the quality of groundwater in most of the wells was class I, II and III and suitable for drinking purposes, but well (S2) has been found to be in class V, which is classified as very poor and cannot be used for drinking. Also, the FME method was compared with the comprehensive evaluation method. The FME method was found to be more comprehensive and reasonable to assess groundwater quality. This study can provide an important frame of reference for decision making on improving groundwater quality in the study area and nearby surrounding.
Keywords: Groundwater quality; Groundwater pollution; Fuzzy mathematics; Physicochemical parameters

Modeling the mass transfer in biosorption of Cr (VI) y Ni (II) by natural sugarcane bagasse by I. L. Rodríguez Rico; R. J. Cabrera Carrazana; N. Kumar Karna; I. Iáñez-Rodríguez; M. Calero de Hoces (1-8).
The Cr (VI) and Ni (II) ion biosorption process by natural sugarcane bagasse in a fixed bed column was investigated. The characteristic removal parameters such as retention capacity, removal percent and unused bed length were experimentally determined at different operating conditions. Overall mass transfer coefficient was investigated and reported for the studied biosorption system. The breakthrough curves were simulated using Matlab2010a software to check the validity of the obtained overall mass transfer coefficients. Experimental data fitted well with predicted data (R 2 = 0.94). A statistical analysis was performed using the software Statgraphics Centurion-X V15.2.06 to compare the simulated and experimental data. No significant differences were observed between experimental and simulated data. The best operating conditions for Cr (VI) removal were 15 mg/L of inlet concentration and 1.5 g of biosorbent. For Ni (II) removal the best results were obtained with 25 mg/L of inlet concentration and 1.5 g of solid. The results obtained through the breakthrough curve showed high removal percentages (94.70 and 97.90% for chromium and nickel, respectively). Moreover, results indicated that sorption of these metals was irreversible and it was controlled by the mass transfer at the external film.
Keywords: Biosorbent; Heavy metals; Pollution; Wastewaters

This study aims to follow the photodynamic and spectroscopic properties of dianionic rose Bengal disodium salt (RB) on Staphylococus aureus (S. aureus) in phosphate buffer solution (PBS) at pH 7.3. It focused on: (1) the effect of several reactive oxygen species (ROS) antioxidants used [such as sodium azide (NaN3), l-tryptophan (l-Trp) and d-mannitol] on the RB photodynamic efficiency as a mean to identify the main ROS attributed, and (2) the possible interactions of the RB with the important singlet oxygen quencher used namely tryptophan and/or between the dye and the bacteria S. aureus thanks to a spectroscopic study. The results showed that 20 µM of RB and 10 min of visible light (50 mW/cm2) with a light fluence dose of 30 J/cm2 are crucial for a good photodynamic action, achieving a reduction of 79.4% in the viability. Rose Bengal photodynamic action was in part inhibited by D-mannitol and l-Trp, indicating the mediation by.OH and 1O2, respectively. The high inhibition of the RB activity against S. aureus by l-Trp is not due only to its singlet oxygen quencher ability but it is mainly due to the interaction between RB and l-Trp as shown spectrophotometrically.
Keywords: Absorption spectra; Quenchers; Tryptophan; Sodium azide; Mannitol; Visible light

Wasting water in toilets flushing is the largest source of water wasting through the use of old siphon boxes. It occupies the first place in domestic consumption. This study reports two trial approaches for optimizing the flushing system design. The first one employs a rotatable blade in the bottom of the bowl. This blade pushes materials in the bowl to cross the trapway thus; less toilet flushing water can be used. The second approach depends on using a rotatable trapway such that it can be tilted down to enable discharging materials in the bowl directly by its gravity. This facilitates the discharge and reduces the flushwater amount which is just used to overcome friction and to clean the passage. Both are mechanical systems actuated by an external pedal mechanism that triggers the water flushing valve system in the same time. Real experiments revealed that the first approach needs more developments to work efficiently. Experiments with restricted conditions revealed that with using the rotatable trapway system approach, less than one liter of flushwater is sufficient. The required flushwater flow rate can be obtained directly from the water supply system without the need to install siphon boxes. This study can help more to design better water saving systems.
Keywords: Water saving; Toilet flushing; Pedal operated flushing system; Fixed trapway; Rotatable trapway

Origin of high fluoride in groundwater of the Tuticorin district, Tamil Nadu, India by C. Singaraja; S. Chidambaram; Noble Jacob; G. Johnson Babu; S. Selvam; P. Anandhan; E. Rajeevkumar; K. Balamurugan; K. Tamizharasan (1-14).
This paper reports the results of higher F and $$ { ext{HCO}}_{3}^{ - } $$ HCO3- concentrations and its response to high pH level in a hard rock terrain in Tamil Nadu, India. About 400 groundwater samples from the study area were collected from a period of four different seasons and analysed for F, $$ { ext{HCO}}_{3}^{ - } $$ HCO3- and other major cations and anions. The key rationale for the higher fluoride and bicarbonate in the study area is the soaring rate of the leaching fluoride-bearing minerals and weathering processes. Fluoride and $$ { ext{HCO}}_{3}^{ - } $$ HCO3- ranges from BDL to 3.30 mgl−1 and 12 to 940 mgl−1, its concentrations are lower for the period of SWM and it increases during POM and reaches to a maximum in PRM. Higher dissolution is observed in the NEM season due to rainfall impact. Spatial distribution and factor score show that the higher concentrations of F and $$ { ext{HCO}}_{3}^{ - } $$ HCO3- are eminent in the northern and central zone of the study area due to the impact of lithology. The higher values in pCO2 versus $$ { ext{HCO}}_{3}^{ - } $$ HCO3- plot indicate higher residence time which favours more water–rock interactions, which further increase the F concentrations in groundwater. $$ { ext{HCO}}_{3}^{ - } $$ HCO3- is linearly correlated with F which indicates that these ions were consequent from the weathering influences. At the same time, poor correlation of F with pH could possibly be due to the increase of alkalinity follow-on from the swell of bicarbonate level with very low Ca2+ that promotes increase in Fconcentration in the groundwater.
Keywords: Fluoride; Bicarbonate; Water–rock interactions; Weathering processes; Lithology; India

Assessment of fluoride in groundwater and urine, and prevalence of fluorosis among school children in Haryana, India by A. K. Haritash; Ankur Aggarwal; Jigyasa Soni; Khyati Sharma; Mohnish Sapra; Bhupinder Singh (1-8).
Considering the health effects of fluoride, the present study was undertaken to assess the concentration of fluoride in groundwater, and urine of school children in Bass region of Haryana state. Fluoride in groundwater was observed to vary from 0.5 to 2.4 mg/l with an average concentration of 0.46 mg/l. On the other hand, F in urine ranged from below the detection limit to 1.8 mg/l among girls and 0.17–1.2 mg/l among the boys. Higher average concentration of fluoride in urine (0.65 mg/l for boys and 0.34 mg/l for girls) may be ascribed to exposure to bioavailable fluoride through food, milk, tea, toothpaste, etc., in addition to intake through groundwater. Relatively more intake of water and food by the boys might be the reason for more cases of severe dental fluorosis (44%) among boys compared to girls (29% cases of moderate to severe dental fluorosis). The groundwater quality for drinking was compromised with respect to dissolved solids, hardness, magnesium ions, and dissolved iron. Hydro-geochemical investigation revealed that rock–water interaction, in terms of direct cation exchange, dominantly regulates groundwater chemistry, and groundwater is of Ca-Na-HCO3 type.
Keywords: Fluoride; Urine; Fluorosis; Groundwater; School children

Tritium as tracer of groundwater pollution extension: case study of Andralanitra landfill site, Antananarivo–Madagascar by Voahirana Ramaroson; Christian Ulrich Rakotomalala; Joel Rajaobelison; Lahimamy Paul Fareze; Falintsoa A. Razafitsalama; Mamiseheno Rasolofonirina (1-11).
This study aims to understand the extension of groundwater pollution downstream of a landfill, Andralanitra–Antananarivo–Madagascar. Twenty-one samples, composed of dug well waters, spring waters, river, and lake, were measured in stable isotopes (δ 2H, δ 18O) and tritium. Results showed that only two dug well waters, collected at the immediate vicinity of the landfill, have high tritium activities (22.82 TU and 10.43 TU), probably of artificial origin. Both upstream and further downstream of the landfill, tritium activities represent natural source, with values varying from 0.17 TU to 1.46 TU upstream and from 0.88 TU to 1.88 TU further downstream. Stable isotope data suggest that recharge occurs through infiltration of slightly evaporated rainfall. Using the radioactive decay equation, the calculated tracer ages related to two recent ground water samples collected down gradient of the landfill lay between [8–15] years and [4–7] years, taking into account the uncertainty of tritium measurements. For the calculation, a value of 2.36 TU was taken as A o. The latter was estimated based on similarity between stable isotope compositions of nearby spring and dug well waters as well as tritium activities of the local precipitation. Calculation of the tritium activities from the contaminated water point having 22.82 TU to further downstream using the calculated tracer ages showed values of one order of magnitude higher than the measured values. The absence of hydrological connection from the contaminated water point to further downstream the landfill would explain the lower tritium activities measured. Groundwater pollution seems to be limited to the closest proximity of the landfill.
Keywords: Groundwater pollution; Landfill; Contamination; Close proximity; Tritium; Andralanitra

Optimizing TOC and COD removal for the biodiesel wastewater by electrocoagulation by N. Pınar Tanattı; İ. Ayhan Şengil; Abdil Özdemir (1-10).
In this study, the chemical oxygen demand (COD) and the total organic carbon content (TOC) in biodiesel wastewater iron and aluminum electrodes arranged in a bipolar position. In the EC of the biodiesel wastewater, the effects of the supporting electrolyte, initial pH, electrolysis time and current density were examined. The results showed that the majority of the pollutants in the biodiesel wastewater were effectively removed when the iron or aluminum electrodes were used as a sacrificial anode. The highest COD and TOC removal efficiencies were successfully obtained with the iron electrode. COD removal efficiencies are 91.74 and 90.94% for iron and aluminum electrode, respectively. In the same way, TOC removal efficiencies were obtained as 91.79 and 91.98% for the iron and aluminum electrodes, respectively, at initial pH of 6, the current density of 0.3226 mA/cm2, NaCl concentration 1 g/L and 1 min of operating time.
Keywords: Electrocoagulation; Biodiesel wastewater; Aluminum electrode; Iron electrode; COD removal; TOC removal

A complete graphical solution is obtained for the completely mixed biofilm-activated sludge reactor (hybrid reactor). The solution consists of a series of curves deduced from the principal equations of the hybrid system after converting them in dimensionless form. The curves estimate the basic parameters of the hybrid system such as suspended biomass concentration, sludge residence time, wasted mass of sludge, and food to biomass ratio. All of these parameters can be expressed as functions of hydraulic retention time, influent substrate concentration, substrate concentration in the bulk, stagnant liquid layer thickness, and the minimum substrate concentration which can maintain the biofilm growth in addition to the basic kinetics of the activated sludge process in which all these variables are expressed in a dimensionless form. Compared to other solutions of such system these curves are simple, easy to use, and provide an accurate tool for analyzing such system based on fundamental principles. Further, these curves may be used as a quick tool to get the effect of variables change on the other parameters and the whole system.
Keywords: Activated sludge; Biofilm carrier; Graphical solution; Hybrid reactor; Steady state; Wastewater treatment

Comparison of infiltration models in NIT Kurukshetra campus by Balraj Singh; Parveen Sihag; Karan Singh (1-8).
The aim of the present investigation is to evaluate the performance of infiltration models used to calculate the infiltration rate of the soils. Ten different locations were chosen to measure the infiltration rate in NIT Kurukshetra. The instrument used for the experimentation was double ring infiltrometer. Some of the popular infiltration models like Horton’s, Philip’s, Modified Philip’s and Green–Ampt were fitted with infiltration test data and performance of the models was determined using Nash–Sutcliffe efficiency (NSE), coefficient of correlation (C.C) and Root mean square error (RMSE) criteria. The result suggests that Modified Philip’s model is the most accurate model where values of C.C, NSE and RMSE vary from 0.9947–0.9999, 0.9877–0.9998 to 0.1402–0.6913 (mm/h), respectively. Thus, this model can be used to synthetically produce infiltration data in the absence of infiltration data under the same conditions.
Keywords: Infiltration rate; Double ring infiltrometer; Coefficient of correlation; Nash–Sutcliffe efficiency; Root mean square error

The main object of this research is to assess the water quality of Shatt Al-Arab River and its suitability for various purposes near power plants (Hartha and Najibia) through physical and chemical analysis [temperature, pH, EC, Cl, Na+, K+, Ca+2, Mg+2, HCO3 , NO3 , SO4−2, Fe+, total alkalinity, total hardness, biological oxygen demand (BOD5), NH4 +, and NO2 ] using water quality index (WQI), organic pollution index (OPI), sodium adsorption ratio (SAR), and percentage of sodium ion (Na%) during the dry season (August, 2016) and the wet season (January, 2017). WQI of Shatt Al-Arab falls under very poor quality during summer season, while it ranges from very poor quality to unsuitable for drinking purposes during winter season. There is a clear effect of power plants on water quality. Hartha and Najibia power plants contribute to the deterioration of water quality by increasing the percentage ratio of WQI near these plants by 13.22 and 9.69%, respectively, compared to the north sites of these plants during summer season. The percentage ratios of increased WQI near Hartha and Najibia power plants compared to the north sites of these plants are 17.93 and 15.92%, respectively, during winter season. Water quality of Shatt Al-Arab falls under a high level of organic pollution during the summer and winter seasons. There is a slight effect by the power plants on the OPI. Hartha and Najibia power plants contributed to the change of the OPI by 10% compared to the north site of Hartha power plant. According to the comparison between the SAR values which represent the suitability of water for serve irrigation purposes and SAR values of Shatt Al-Arab, all sites lie in the first class (excellent). According to Na+%, the type of surface water in the studied area lies in good class during winter season and permissible class during summer season.
Keywords: Hartha; Najibia; Power plant; Shatt Al-Arab River; WQI; OPI

Synthesis, characterization, and photocatalytic application of Pd/ZrO2 and Pt/ZrO2 by Khalid Saeed; Mohammad Sadiq; Idrees Khan; Saleem Ullah; Nauman Ali; Adnan Khan (1-6).
Zirconia-supported palladium (Pd/ZrO2) and Zirconia-supported platinum (Pt/ZrO2) nanoparticles (NPs) are synthesized from their precursors via impregnation technique. The Pd/ZrO2 and Pt/ZrO2 NPs were analyzed via SEM and EDX, while the study of indigo disulfonate dye degradation was carried out by UV/VIS spectrophotometer. The SEM micrographs illustrated that the Pd and Pt NPs were well placed on ZrO2 surface. The Pd/ZrO2 and Pt/ZrO2 NPs were also employed as photocatalysts for the photodegradation of indigo disulfonate in an aqueous medium under UV-light irradiation. The photodegradation study presented that Pd/ZrO2 and Pt/ZrO2 NPs degraded 96 and 94% of indigo disulfonate in 14 h, respectively. The effect of pH of medium and catalyst dosage and efficiency of recovered Pd/ZrO2 and Pt/ZrO2 NPs on the photocatalytic degradation were also studied. It was also found that the maximum degradation of dye was found at pH 10 (95–97%) and at 0.02 g weight (40.28%).
Keywords: Indigo disulphonate; Photodegradation; Nanoparticles; Scanning electron microscopy

Indigenous knowledge on development and management of shallow dug wells of Dodoma Municipality in Tanzania by C. Shemsanga; A. N. N. Muzuka; L. Martz; H. Komakech; E. Mcharo (1-20).
Dodoma city, central Tanzania, seats in a semi-arid region of East Africa with limited rains and surface water resources. Consequently, the area largely depends on shallow and deep aquifers for its freshwater needs. Owing to harsh climatic conditions, chronic lack of year-round surface water bodies and, limited development of water distribution infrastructures, over year’s local people have nurtured, developed and, passed on important indigenous knowledge (IK) on exploiting and managing shallow aquifers (SAs). However, there is no clear documented administrative plans for the SAs and the roles of IK, which is widely practised in developing SDWs and managing SAs, are not properly documented. This study intended to assess the extent of shallow dug wells (SDWs) utilization and contribution of IK on management of SAs of indigenous people of Dodoma Municipality. The methods followed include critical field observations, measurements and, focus group discussions done during both the dry season (Sep.–Oct. 2013) and wet season (Dec. 2013–Feb. 2014). The results show that SDWs occur widely in the city, particularly in the suburbs, where they often serve as the only sources of freshwater and heavily dependent by the populace. It is clear that there is rich IK on management of SAs including on groundwater exploration, digging, water allocation, pricing, and even on water quality and, water treatment skills. The aforementioned IK clearly contribute to water sufficiency to the populace and general management of groundwater such as enhancing recharge mechanisms where about 1% of local rainfall is recharged through a network of SDWs compared to ~ 5–10% that is naturally being recharged by rainfall through the vadose zone. Thus, as much as the current policy framework and groundwater managers do not recognize the roles of IK and contributions of SDWs as key water sources, it is clear that IK contributes to the groundwater management and SDWs already support large part of the society. While it is globally appreciated that vital skills on SDWs management are vanishing, local people in Dodoma still retain them and should, therefore, be preserved. It is further recommended that IK are strengthened, improved and most importantly, incorporated in the local water resources management plans that already advocate on integrated approaches but which clearly ignores the IK and the local people’s efforts to explore and manage water resource, particularly SAs.
Keywords: Shallow aquifers; Indigenous knowledge; Management; Dodoma

Identifying potential effects of climate change on the development of water resources in Pinios River Basin, Central Greece by G. Arampatzis; A. Panagopoulos; V. Pisinaras; E. Tziritis; F. Wendland (1-17).
The aim of the present study is to assess the future spatial and temporal distribution of precipitation and temperature, and relate the corresponding change to water resources’ quantitative status in Pinios River Basin (PRB), Thessaly, Greece. For this purpose, data from four Regional Climate Models (RCMs) for the periods 2021–2100 driven by several General Circulation Models (GCMs) were collected and bias-correction was performed based on linear scaling method. The bias-correction was made based on monthly precipitation and temperature data collected for the period 1981–2000 from 57 meteorological stations in total. The results indicate a general trend according to which precipitation is decreasing whilst temperature is increasing to an extent that varies depending on each particular RCM–GCM output. On the average, annual precipitation change for the period 2021–2100 was about − 80 mm, ranging between − 149 and + 35 mm, while the corresponding change for temperature was 2.81 °C, ranging between 1.48 and 3.72 °C. The investigation of potential impacts to the water resources demonstrates that water availability is expected to be significantly decreased in the already water-stressed PRB. The water stresses identified are related to the potential decreasing trend in groundwater recharge and the increasing trend in irrigation demand, which constitutes the major water consumer in PRB.
Keywords: Climate change; Water resource regional climate models; Precipitation; Temperature; Pinios River Basin