Hasil untuk "Water supply for domestic and industrial purposes"

Alicia Raquel Eisenkölbl, Rafaela Laino-Guanes, Christian Vogt-Penzkofer et al.

La investigación analiza la calidad del agua subterránea y la eficacia del funcionamiento de dos plantas de tratamiento de efluentes domiciliarios en dos centros urbanos de Paraguay, así como la presencia de metales pesados en lodos residuales de ambas plantas de tratamiento. Para analizar la calidad del agua subterránea se recabaron datos de 59 muestreos de agua de 17 pozos profundos obtenidos en un periodo de 10 años entre 2006 y 2016. Para la evaluación del funcionamiento de las plantas de tratamiento se determinó la calidad de los efluentes luego del proceso de depuración. En los lodos generados en ambas plantas se analizó la presencia de metales pesados (Pb, Cr total, Cd y Hg). Los resultados obtenidos se contrastaron con legislaciones nacionales e internacionales vigentes. Los datos cuantitativos se procesaron estadísticamente mediante análisis de varianza y contraste de medias (test de Duncan) con margen de error de 5 %. Los principales resultados indican contaminación microbiológica del agua subterránea (acuífero Guaraní). Sin embargo, los parámetros físico-químicos analizados estaban dentro de los rangos establecidos por las normativas vigentes. Se identificó una inadecuada gestión en la planta de tratamiento de aguas residuales en uno de los centros urbanos (Hohenau). Se detectó presencia de Pb, Cr y Hg, a pesar de que las concentraciones se mantuvieron dentro de los rangos permisibles. Para salvaguardar la salud pública y el ambiente tanto a nivel local como regional es imperativo aplicar plenamente el marco legal y la implementación de la gestión integrada de los recursos hídricos.

Idris O. Sanusi, Godwin O. Olutona, Ibrahim G. Wawata et al.

Abstract Groundwater and surface water quality is of great significance for humanity as they serve as the primary drinking water sources globally. Due to population growth and the need to provide people with necessities that depend on water as an essential resource, these bodies of water are becoming more polluted. The present study involved the collection of groundwater and surface water samples from Kampala and Mbarara districts in Uganda during the dry and wet seasons. Also, concentrations of lead (Pb), manganese (Mn), cadmium (Cd), copper (Cu), and iron (Fe) were analyzed in order to evaluate the toxicity of metals, identify potential sources, and determine the health risk associated with their presence in water. Results showed that metals were observed with higher concentration during the wet season than the dry season. The concentrations of Fe (8.646 ± 0.00 mg/L), Mn (2.691 ± 0.01 mg/L) and Cd (0.090 ± 0.41 mg/L) measured in groundwater were significantly higher than those measured in surface water. However, only Cu was observed with higher concentration (0.322 ± 0.06 mg/L) in surface water during the wet season. Furthermore, the degree of contamination (Cd) and the heavy metal pollution index (HPI) were evaluated for both the wet and dry seasons. Results showed that few samples were found in the category of portable drinking water while majority are within the “poor” and “very poor” classes which require proper treatment before consumption. The oral hazard index (HIoral) results showed that none of the samples are suitable for consumption; therefore, cause potential non-carcinogenic health issues to the consumer (HIoral > 1). Moreover, children are more at risk than adults in the study districts (higher HI values in both seasons). This study recommends frequent monitoring of quality of water and also effluent waste treatment by the major source of pollution.

Hailekiros Tadesse, Desta Berhe Sbhatu, Gebreselema Gebreyohannes

Mekelle is one of the Ethiopian cities suitable for urban and peri-urban agriculture for cultivating leafy vegetables using wastewater. The consumption of unprocessed and processed leafy vegetables is also very high in the city. Wastewater samples collected from four experimental sites (ESs) in Hadnet district of the city had higher concentrations in 4 (i.e., Cd, Cr, Cu, and Mn) of the 10 heavy metals tested than the permissible limit established by pertinent standards. Spring water samples collected from another site called Kallamino, designated as a comparison site, also had higher concentrations in 4 (i.e., Al, As, Cd, and Cu) of the 10 heavy metals tested. However, the leafy vegetables grown in the least contaminated ES had higher concentrations in 6-7 of the 10 heavy metals tested. The lettuce and spinach samples had elevated concentrations of As and Al, respectively. The wastewater used to irrigate vegetable farms in Hadnet district is not safe enough. More importantly, the soils of the farms might have accumulated far more heavy metals. The cultivated lettuce, spinach, and cauliflower are highly contaminated. Thus, the use of wastewater for irrigating urban and peri-urban farms needs to be regulated. HIGHLIGHTS Tests of wastewaters used in urban agriculture for heavy metal contents.; Tests of three leafy vegetables irrigated with wastewater for heavy metal contents.; Contamination of the three leafy vegetables with high level of 6 to 7 heavy metals tested.;

Charles Perry

Editor-in-Chief's Note: In every odd-numbered year, the Texas Legislature convenes in regular session for 140 days. With this in mind, the Texas Water Journal invited Senator Charles Perry, Chairman of the Senate Water, Agriculture, and Rural Affairs Committee to discuss his priorities and visions for Texas water and the regular session of the 89th Texas Legislature. The opinion expressed in this commentary is the opinion of the individual author and not the opinion of the Texas Water Journal or the Texas Water Resources Institute, or the Bureau of Economic Geology.

América N. Lutz-Ley, Pablo A. Reyes-Castro

Una de las consecuencias más importantes del cambio climático para México se relaciona con un menor acceso a cantidades y calidades de agua suficientes para los usos humanos y ambientales. El ahorro de agua doméstica se enmarca en dicho contexto como una medida de adaptación frente el cambio climático. El objetivo de este trabajo es explorar los factores que afectan el ahorro de agua en hogares mexicanos. Para ello, se utilizan datos de más de 13 mil hogares de la Encuesta Nacional de los Hogares (ENH) desarrollada en 2017, y del Módulo de Hogares y Medio Ambiente aplicado ese año con la ENH. A través de análisis de regresión se prueba el efecto de factores sociodemográficos (edad, sexo, nivel educativo y tamaño de localidad), de gestión (forma de cobro del servicio) y climáticos (percepción de cambios en temperatura, precipitación y fenómenos extremos) como predictores de prácticas de ahorro de agua en hogares urbanos y rurales. Los hallazgos apuntan a un efecto estadísticamente significativo y positivo del cobro del agua a través de micromedición; así como efectos significativos, pero menores, de la percepción de mayor temperatura, cambios en la lluvia, e impactos de fenómenos climáticos en el hogar, como factores relacionados positivamente con prácticas de ahorro de agua doméstica.

Shailaja Gandla, Bhavana Umrikar, Nyakno Jimmy George et al.

Abstract The hydrochemistry of groundwater in the Mann River basin, situated in eastern Maharashtra, was investigated through laboratory analysis with the aim of determining its suitability for consumption, agriculture, and industry. A total of 43 groundwater samples were collected from bore wells and dug wells across the basin for evaluation. Parameters including pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), and various cations and anions were examined in comparison with established standards set by the World Health Organization (WHO) and the Bureau of Indian Standards (BIS). Piper diagram analysis revealed that a significant portion of the samples fell into the CaMgHCO3 hydrochemical facies, while the Gibbs diagram suggested rock dominance in most samples. The drinking water quality index was calculated based on 11 parameters, with 52% of the samples falling into the excellent water category. The irrigation suitability assessment was based on parameters like the sodium adsorption ratio (SAR), percent sodium (%Na), and permeability index (PI), revealing that the majority of the samples were appropriate for irrigation. Moreover, assessments of industrial suitability rely on factors such as the Langelier saturation index (LSI) and Ryznar stability index (RSI) to estimate corrosion potential, with most samples showing a high propensity for corrosion and calcium carbonate deposition. Binary correlation effects were observed, suggesting that the presence of one physiochemical parameter could influence others. GIS-based maps were generated to precisely assess corrosion indices for effectively monitoring and managing water quality in the study area. This study is crucial as it evaluates the groundwater quality for its suitability for drinking, agriculture, and industry. It identifies groundwater’s chemical characteristics, irrigation potential, and corrosion risks, offering key insights for water management, ensuring safe consumption, and supporting agricultural and industrial applications.

Abhyavartin Selvam, Prathu Raja Parmar, D. Bandyopadhyay et al.

Rapid industrialization in the developing countries has facilitated the unwanted mixing of wastes into the already depleting sources of potable, domestic and industrial water. In particular, the mixing of toxic heavy metal wastes into the aquatic resources have not only increased the scarcity of water at the different levels of usage but also hygiene of the ecosystem is further threatened by the presence of abysmal quality of aquatic environment around the living world. Thus, it has become quite imperative to mitigate such problems through the removal of such water contaminants at the sources before supplied for a specific purpose. In this direction, among the other available mass transfer techniques, specific and efficient adsorption of heavy metal species on the nanomaterials such as metal‐organic frameworks (MOFs) are found to be a promising method of heavy metal ions recovery. This reports targets to provide a new perspective into heavy metal ions removal from wastewater as a rationale for sustainable nanomaterial engineering through the recycling of toxic metal species as precious precursors in the synthesis of nanomaterials. Decades of exploring materials sciences led to the generation of groundbreaking materials of nanoscale regime, which has advanced myriad avenues of science and technology, viz. electronic, energy, biomedical, environmental, agriculture applications, and more. In this regard, nanotechnology has had a global impact by several folds, which can be observed in all day‐to‐day facilities. This perspective aims to conceptualize a strategy of wastewater decontamination through the adsorptive retrieval of heavy metal species to be subsequently recycled in the design of smart nanomaterials.

Akaamaa W. W, Onoja S.B, Nwakonobi T.U. et al.

Nasarawa State in Nigeria, is host to several mineral deposits. The groundwater resources in the State plays an important role in the socio-economic life of the people in terms of domestic, industrial and agricultural water supply. The effect of climate change, on the surface and groundwater resources, couple with the anthropogenic and geogenic activities on the quality of the various groundwater sources remained uncertain. Two hundred (200) water samples were collected randomly from boreholes and hand-dug wells from five locations (20 each) in Nasarawa South: Keana, Obi, Lafia and Awe Local Government Areas of the State, referred to as Middle Benue trough. 100 samples were collected during peak of dry season and another 100 during peak of rainy season. Cations, anions and heavy metals were analyzed using atomic absorption spectrometry (AAS); with aim of determining their concentrations in relation to suitability within the tolerance limit. The results revealed that heavy metals such as lead (Pb), manganese (Mn), Magnesium (Mg) and arsenic (As) have concentrations above World Health Organization (WHO 2017) and SON (2015) standards. The high concentrations are mostly associated with the Baryte and Lead-zinc mineralization present in Keana / Awgu formations in the Middle Benue Trough. Zinc (Zn), copper (Cu), cadmium (Cd), and iron (Fe2+) have their concentrations within World Health Organization (WHO 2017) drinking water permissible limits. The cations and anions present in the groundwater in the study areas had varying levels in terms of physico-chemical and bacteriological quality. In some areas bacteriological contamination rendered water sources unfit for human consumption, but suitable for agricultural purposes. Therefore, regular monitoring of the water sources in the affected areas are highly recommended.

Gopal Chandra Ghosh, Tapos Kumar Chakraborty, Nipa Shekder et al.

This study investigated the groundwater quality and its associated human health risks in the urban and peri-urban areas of Jashore, Bangladesh, where groundwater samples were collected from 67 randomly selected tube wells. The concentration of arsenic, iron, and manganese was analyzed by atomic absorption spectroscopy (AAS). The water quality index indicates that about 89 and 43% of groundwater samples are not consumable for the urban and peri-urban areas, respectively. All of the source water is significantly contaminated with Escherichia coli for urban (31 ± 17.77 CFU/100 mL) and peri-urban areas (76.12 ± 35.17 CFU/100 mL), where about 67 and 57% of water source has intermediate and high microbial risk of E. coli for urban and peri-urban areas, respectively. Children and adults face unacceptable non-carcinogenic health risks for the urban area (4.13–10.67 for adults; 9.65–24.91 for children) and peri-urban area (1.05–5.58 for adults; 2.46–13.03 for children) via oral ingestion. Both groups (e.g. children = 4.25E-03 to 1.10E-02 and adult = 1.82E-03 to 4.71E-03 for urban regions; children = 1E-03 to 5E-03 and adult = 4.29E0-04 to 2.14E-03 for peri-urban regions) face undesirable carcinogenic risks from arsenic. In addition, children are suspected to have 2.33 times higher non-carcinogenic and carcinogenic health risks than adults. HIGHLIGHTS About 89 and 43% of groundwater samples are not drinkable for the urban and peri-urban areas, respectively.; About 67 and 57% of water source has intermediate and high microbial risk by Escherichia coli for urban and peri-urban areas, respectively.; Children are suspected to have 2.33 times higher non-carcinogenic and carcinogenic health risks than adults.;

Anup Kumar, Himanshu, Satish Kumar

Water is important for living beings for drinking and other domestic uses. Good quality water plays vital role in establishment of human health, settlements, agriculture and industrial growth. Good quality groundwater is important mainly for drinking purpose because polluted drinking water can cause many health problems. Geospatial techniques including remote sensing satellite data, geographical information system (GIS) and global positioning system (GPS) are playing vital role in assessment of groundwater quality. In the present study spatial groundwater quality has been assessed for drinking purpose in Charkhi Dadri district of Haryana. Charkhi Dadri district is located between latitudes 28.385446 N to 28.814909 N and longitudes 75.815527 E to 2 76.466172 E and covers 1377 km . In the study area forty three groundwater samples were collected in 250 ml double capped plastic bottles. Groundwater samples were analyzed using Field Water Testing Kit prepared by Tamil Nadu Water Supply and Drainage (TWAD) Board, Chennai for twelve chemical parameters i.e. pH, alkalinity, hardness, chloride, total dissolved solids, fluoride, iron, ammonia, nitrite, nitrate, phosphate and residual chlorine. Point chemical data were converted into spatial form in ArcGIS 10.4.1 software using inverse distance weighted (IDW) interpolation technique. The interpolated groundwater quality data were categorized in three classes i.e. desirable, permissible and non-potable as per BIS (IS 10500:2012) drinking water standards and calculated the area of each drinking water class for each chemical parameter. The spatial distribution of 2 chemical parameters in the study area shows that pH, nitrite, phosphate, residual chlorine cover 1377 km area 2 2 2 under desirable, alkalinity covers 3 km area under desirable, 1371 km area under permissible and 3 km area 2 2 2 under non-potable, hardness covers 209 km area under desirable, 992 km area under permissible and 176 km 2 2 area under non-potable, chloride covers 448 km area under desirable, 863 km area under permissible and 26 2 2 2 km area under non-potable, TDS covers 1239 km area under permissible and 138 km area under non2 2 2 potable, fluoride covers 119 km area under desirable, 401 km area under permissible and 857 km area under 2 2 non-potable, iron covers 1205 km area under desirable and 172 km area under non-potable, ammonia covers 2 2 2 954 km area under desirable and 423 km area under non-potable, nitrate covers 1377 km area under nonpotable. The study is highly useful for drinking water supply department as well as local users for searching good quality drinking water sites in the study area.

F. Frappart, V. Merwade

Groundwater, with a total volume of 23.4 × 10 km, represents 30% of the world’s freshwater or 2.5% of the total global water storage. Thus, it is an important area of research and a valuable resource for humankind (Oki and Kanae, 2006). Groundwater is an essential component of the global hydrological and biogeochemical cycles and plays a major role in ecosystems sustainability (Zektser and Loaiciga, 1993; Jackson et al., 2001; Sophocleous, 2002; Griebler and Avramov, 2015; Frappart et al., 2019). Similarly, groundwater is an essential water resource for meeting various human needs, including domestic water supply, irrigation and industrial operations. Groundwater is often the last freshwater resource available for domestic use and irrigation once surface waters are depleted, especially in semi-arid areas and densely populated countries (Giordano, 2009; Siebert et al., 2010). In many regions of the world, aquifers are the largest and safest drinking water supply (Doveri et al., 2015). Groundwater storage and flows are increasingly affected by human activities (Zektser and Everett, 2004; Shah, 2007) and climatic stresses (Döll, 2009; Green et al., 2011; Taylor et al., 2013). This may have negative consequences both for the functioning of the terrestrial environment and ecosystems as well as water supply for large populations due to the depletion of groundwater levels in many regions around the world. A depletion of 4,500 km was estimated worldwide between 1900 and 2008 (Konikow, 2011). Despite this global groundwater crisis (Famiglietti, 2014), groundwater is either poorly monitored or not monitored in many regions of the world (Jones, 2011). Thus, there is an urgent need to understand the properties and behaviour of groundwater systems around the world to support sustainable water resources managment. The authors in this Research Topic provided original contributions on two broader topics: i) modelling and mapping of groundwater systems; and ii) impact of natural and anthropogenic stresses on groundwater supply. Kaewdum and Chotpantarat analyzed groundwater recharge potential in the lower Khwae Hanuman sub-basin in Thailand based on geological and hydrogeological features. This region anually faces water shortage during the dry season and groundwater is used as an additional freshwater source, especially for irrigation purposes. Using a weighted OPEN ACCESS

Elaid Madene, A. Boufekane, M. Meddi et al.

The proposed study aims to assess groundwater quality and suitability of the Upper and Middle Cheliff plains (northwest of Algeria) for irrigation and drinking. Here the groundwater is the main source for domestic, agricultural and industrial activities similarly to any others region of the world. The suitability for drinking and for irrigation was evaluated on the basis of water quality index, salinity risk, hardness risk, sodium risk, magnesium risk, permeability index, water infiltration rate, Kelly index and Wilcox and Richards diagrams. The aquifer system is mainly composed by alluvium (gravel, sand, silt, clay, …) from the Mio-Plio-Quaternary. The results of this study highlighted that the majority of the chemical elements analyzed exceed the WHO's drinking water standards and FAO's irrigation water standards. Based on the GroundWater Quality Index (GWQI) results, the Upper and Middle Cheliff groundwater plains shows Doubtful class in most of the plains. In addition, the GroundWater quality Index for Irrigation (GWQII) shows the predominance of the Good/Permissible groundwater quality class in most of the plains. According to these results, drinking water can cause health problems (a danger) for the human consumption making necessary a proper treatment be able to use it. As for irrigation water, it does not present a danger for irrigating for the vast fields of the region, with the exception of sensitive crops such: garlic, onion, beans and strawberry. The proposed approach demonstrated to be appropriate in assessing the groundwater quality for irrigation and drinking water supply since it can be easy applicable and suitable in humid, arid or semi-arid regions around the world.

Behnam Roshanzadeh, Levi Reyes Premer, Gowtham Mohan

Energy consumption is steadily increasing with the ever-growing population, leading to a rise in global warming. Building energy consumption is one of the major sources of global warming, which can be controlled with renewable energy installations. This paper deals with an advanced evacuated hybrid solar photovoltaic–thermal collector (PVT) for simultaneous production of electricity and domestic hot water (DHW) with lower carbon emissions. Most PVT projects focus on increasing electricity production by cooling the photovoltaic (PV). However, in this research, increasing thermal efficiency is investigated through vacuum glass tube encapsulation. The required area for conventional unglazed PVT systems varies between 1.6–2 times of solar thermal collectors for similar thermal output. In the case of encapsulation, the required area can decrease by minimizing convective losses from the system. Surprisingly, the electrical efficiency was not decreased by encapsulating the PVT system. The performance of evacuated PVT is compared to glazed and unglazed PVTs, and the result shows a 40% increase in thermal performance with the proposed system. All three systems are simulated in ANSYS 18.1 (Canonsburg, PA, USA) at different mass flow rates and solar irradiance.

Neda Jodeyri Heydari, Abdolmajid Liaghat

Wick irrigation is a combination of subsurface and pot irrigation methods that provides water to the plant roots through the wick by means of capillary ascent. The salient features of this method are the elimination of evaporation losses and deep penetration, and thus increase plant yield and water use efficiency. The purpose of this study was to investigate the performance and water use efficiency of a wick system designed for corn cultivation in comparison with surface-furrow irrigation method. In this study, after reviewing and selecting the most suitable wick, field studies with two treatments of wick irrigation and furrow irrigation were performed in the summer of 2017 in one crop season and the wick system was prepared and implemented. Based on the results obtained, the total volume of water consumed in the wick system has decreased by about 30% on average compared with the surface system and its wet and dry performance has increased by about 1.4 and 1.7 times, respectively. Therefore, water use efficiency for maize plant in wick irrigation method increased by 2.5 times compared with surface method. The results show the effectiveness of wick irrigation method on yield and water use efficiency for corn cultivation in semi-arid areas compared with surface-furrow irrigation method.

Ziqi Zhang, Xiaoman Yan, Kevin C. Jones et al.

Abstract Pesticides applied worldwide to meet food demand is recognized as a key threat to the Sustainable Development Goals (SDGs) set by the United Nations. Studies on pesticide risks employ different ingredients, methods or specific environments, which makes it difficult to quantify the scale of the problem. Furthermore, the complex influences and hotspots of long-term pesticide usage remain unclear. Herein, we present a national-scale study of four typical pesticides in China, the world’s largest pesticide user. The spatiotemporal changes in legacy and risk of pesticides over 30 years were analyzed using a modified fugacity model approach coupled with comprehensive ingredient database. Pesticide risk in mainland China might last until 2075 due to the previous legacy, although the usage has declined since 2014. The use of target pesticides was estimated as 2.38 × 105 tonnes in 2017, and about 6.59 × 103 tonnes discharged into the ocean from major basins. Risk areas expanded from 47% in 1991 to 79% in 2017, with 30% at high risk. Of the risk areas, 31% were highly populated while 3% had high biodiversity. 7% of mainland China suffered from both limited water resource and high pesticide risk. It is shown that the improper substitution with lower toxicity pesticides would make the proportion of high-risk regions unexpectedly increased from 18% to 44% due to the longer half-lives of the alternatives. Pesticides pose risks to environmental and human health, and the tailored assessment tool will be vital in contributing towards future pesticide management and meeting sustainability targets in China.

Meseret B. Addisie

The reliable estimation of groundwater recharge is fundamental to the appropriate use of groundwater resources. Shallow groundwater resource quantification for irrigation in highland regions remains challenging. Specifically, in the humid Ethiopian highlands, only limited research has been done on groundwater recharge estimation. Despite the various techniques used to determine recharge, the objective of this study was to better understand natural groundwater recharge using water table fluctuation (WTF) and empirical methods in the sub-humid Ethiopian highlands. The Ene-Chilala watershed was selected for this study. Precipitation, infiltration rate, and piezometric water levels were measured. Precipitation was measured over a 4-year period (2013–2016), whereas infiltration and the groundwater table were measured over a 1-year period (2014). Recharge rates using WTF were determined from the three slope positions and the median of all piezometers for the whole watershed. Infiltration rates on the upslope were greater compared to the mid- and downslopes. The rainfall intensity exceeded the infiltration rate in all slope positions, so the excess rainfall recharged the perched upslope aquifer and eventually drained as interflow to recharge the mid- and downslopes. The estimated groundwater recharge from WTF was less compared to the average of empirical estimations. Surprisingly, from the nine selected empirical equations, the modified Chaturvedi formula had a similar estimation to the WTF method. In conclusion, it is challenging to find long-term seasonal and spatial groundwater-level data. Long-term groundwater data should, therefore, be available in order to arrive at a reliable recharge estimate and for effective groundwater management practices. HIGHLIGHTS Various methods estimate groundwater recharge in tropical monsoon highlands.; Water table fluctuation (WTF) demonstrated recharge at different slope positions.; The modified Chaturvedi equation exactly estimates recharge as WTF using only rainfall.; WTF and empirical equations vary only by 1.8% of the estimated average recharge.;

M. Amini, Maliheh Arab, M. G. Faramarz et al.

Mohammed Falah Allawi, O. Jaafar, F. Hamzah et al.

Abstract Obtaining successful operation rules for dam and reservoir systems is crucial for improving water management to meet the increase in agricultural, domestic and industrial activities. Several research efforts have been developed to generate optimal operation rules for dam and reservoir systems utilizing different optimization algorithms. The main purpose of an operation rule is to minimize the gap between water supply and water demand patterns. To examine the optimized model performance, the simulation of a dam and reservoir system is usually carried out for a particular period utilizing the generated operation rule. During the simulation procedure, although reservoir inflow and evaporation are stochastic variables that are required to be forecasted during simulation, they are considered deterministic variables. This study attempts to integrate a forecasting model for reservoir inflow and evaporation with the operation rules generated from optimization models during the simulation procedure. The present study employs several optimization models to generate an optimal operation rule and two different forecasting models for reservoir inflow and reservoir evaporation. The three different optimization algorithms used in this study are the genetic algorithm (GA), particle swarm optimization (PSO) algorithm and shark machine learning algorithm (SMLA). Two different forecasting models have been developed for reservoir inflow and evaporation using the radial basis function neural network (RBF-NN) and support vector regression (SVR). It is necessary to analyze the proposed simulation procedure for examining the operation rule to comprehend the analysis under different optimal operation rules and levels of accuracy for both hydrological variables. The suggested models have been applied to generate optimal operation policies and reservoir inflow and evaporation forecasts for the Timah Tasoh dam (TTD) located in Malaysia. The results show that the major findings regarding the model performance during the simulation period indicate the necessity to pay attention to evaluating the optimized model performance by considering the results of the forecasting model for both the hydrological variables of reservoir inflow and reservoir evaporation rather than the deterministic values.

Ayesha Siddiqua Asha, A. S. M. Saifullah, Md. Galal Uddin et al.

Abstract This study was carried out to assess the levels of trace metals (Fe, Zn, Mn and Cu) in the macroalgae and sediment of the Sundarban mangrove estuary in Bangladesh. In this connection, macroalgae, water and sediment samples were collected seasonally (pre-monsoon, monsoon and post-monsoon) for a year from the study area. The surface water of the estuary was found to be quite rich in NO3, PO4 and NH4, which is more than that of the sediment pore water. Trace elements were determined using an atomic absorption spectrophotometer. The amount of trace metals in the samples were found in the order of Fe > Mn > Zn > Cu. Enrichment factor was done for trace metals in sediment and showed non-crustal origin of Zn and Cu in the monsoon period. Analysis of variance revealed the seasonal variation of trace metal concentration in sediment (except Mn; p > 0.05) and macroalgae (except Zn; p > 0.05). Iron in sediment showed significant positive correlation both with Fe (r = 0.84, p < 0.05) and Mn (r = 0.87, p < 0.01) in macroalgae. Similarly, Cu in sediment demonstrated a significant positive correlation with Cu in macroalgae (r = 0.81, p < 0.01). The findings reveal a significant communication of metals in sediment and macroalgae.

O. AkinladeY.

Water is a unique substance that has many physical properties distinct from those possessed by other liquid, gaseous, or solid materials existing on the earth’s surface. Water is colourless and transparent substance which is not distributed uniformly over the surface of the earth, as some areas are blessed with a fairly uniform and more than adequate supply for human needs, while many other regions have a greater need for water than they can supply. Water is essential for the existence of all life forms; it is a vital need that man cannot survive without it. water is life and its importance in the life of man, animals and plants cannot be overemphasized. However, the task of meeting domestic water needs in rural and urban areas in most developing countries, particularly in Nigeria, is enormous and falls mainly to women and children. Households also spend considerable time and effort fetching water from sources such as rivers, streams, ponds, wells and boreholes. The most important fresh water resources are rivers (Kolawole et al. 2011). Rivers play a basic role in assimilating the urban waste water, industrial wastes and surface run off from agricultural fields (Basu and Lokesh 2014). Human being and other living organisms depend on water for their survival.Quality of different water resources is subjected to ongoing consequences of water pollution and these results in the increase in demand for monitoring its quality. Water is considered polluted if some substances or condition is present to such a degree that the water cannot be used for a specific purpose (W.H.O., 2017). If the concentration of substances naturally present in water increases then also the water is said to be polluted. Olaniran (1995) defined water pollution to be the presence of excessive amounts of a hazard (pollutants) in water of water quantity in such a way that it is no long suitable for drinking, bathing, cooking or other uses. Testing of the water quality is an essential part of environmental monitoring. The aquatic life as well as surrounding ecosystem is affected when water quality is poor. The quality must be tested with different physico-chemical parameters and the selection of parameter for testing Abstract: Inadequate safe water remains a threat to human health in Ibadan Metropolis of Oyo State, Nigeria. The Asejire reservoir is considered a major source of water in Ibadan and water pollution is pronounced as a result of growing population and urbanization in the area it serves. In this study, We studied and analysed water quality parameters of treated and untreated water samples from Asejire Reservoir of Oyo state, Nigeria. We examined the conformance of the sample parameters to the W.H.O 2017 standards for safe and acceptable drinking water parameters. Data were obtained from the Oyo State water corporation which contained values on water quality parameters such as turbidity, colour, pH, alkalinity, etc. Correlations between values of the pollutants were examined for collinearity before estimating linear discriminant functions (LD) that helped to classify water samples into any of “safe and acceptable”, “safe but unacceptable”, “unsafe yet acceptable” and “unsafe and unacceptable”. The estimated discriminant function had a efficiency of up to 84.3% in correctly predicting the class of water sample based on “appearance”, “colour”, “turbidity”, “taste and odour”, “alkalinity”, “hardness”, “chloride”, “iron”, “manganese” and “total dissolved solids”. Results also showed that of all the 41 water samples which were regarded as final and ready for distribution; 7.3% were potentially unsafe and unacceptable for consumption as they were either polluted with iron or dissolved solids from domestic, industrial, agricultural wastes, insecticides and pesticides.