Water Quality Index Research Articles

Land-Use Pattern-Based Spatial Variation of Physicochemical Parameters and Efficacy of Safe Drinking Water Supply along the Mahaweli River, Sri Lanka

Exploration of the pollution status of river-based water sources is important to ensure quality and safe drinking water supply for the public. The present study investigated physicochemical parameters of surface water in the upper segment of River Mahaweli, which provides drinking water to the Nuwara Eliya and Kandy districts of Sri Lanka. River surface water from 15 intakes and treated water from 14 Water Treatment Plants (WTPs) were tested for pH, water temperature, turbidity, EC, COD, 6 anions, 21 cations, 3 pesticides, and 30 antibiotics once every 3 months from June 2022 to July 2023. Except for turbidity and iron concentrations, all other parameters were within the permissible range as per the Sri Lanka Standard Specification for Potable Water (SLS 614:2013). The uppermost Kotagala WTP raw water had a high concentration of iron due to runoff from areas with abundant iron-bearing minerals. Turbidity increased as the river flowed downstream, reaching its highest value of 13.43 NTU at the lowermost Haragama. Four intakes had raw surface water suitable for drinking as per the Water Quality Index (WQI). Pollution increased gradually towards downstream mainly due to agricultural runoff, industrial effluents, and urbanization. Poor water quality at the upstream Thalawakale-Nanuoya intake was due to highly contaminated effluent water coming from Lake Gregory in Nuwara Eliya. Cluster analysis categorized WTP locations in the river segment into 3 clusters as low, moderate, and high based on contaminations. Principal component analysis revealed that the significance of the 41.56% variance of the raw water was due to the pH and the presence of heavy metals V, Cr, Ni, Rb, Co, Sr, and As. All treated water from 15 WTPs had very good to excellent quality. In general, heavy metal contamination was low as indicated by the heavy metal pollution index (HPI) and heavy metal evaluation index (HEI). The treatment process could remove up to 94.7% of the turbidity. This is the first attempt to cluster the river catchment of the Mahaweli River based on physicochemical parameters of river water. We present here the land-use pattern-based pollution of the river and efficacy of the water treatment process using the Mahaweli River Basin as a case study. Regular monitoring and treatment adjustments at identified points are recommended to maintain the delivery of safe drinking water.

Pollution source characterization and evaluation of groundwater quality utilizing an integrated approach of Water Quality Index, GIS and multivariate statistical analysis

ABSTRACT The Mid-Gangetic Plain, a vital farmland in India, faces increasing groundwater quality deterioration due to anthropogenic activities. This study aimed to assess groundwater quality and contamination sources in the region utilizing statistical methods. A total of 78 groundwater samples were collected and analyzed using standard methods. The hydrochemistry analysis of samples revealed that several parameters such as Ca2+, Mg2+, HCO3−, NO3−, F− and PO43− surpassed the limits prescribed by the Bureau of Indian Standards (BIS). The principal component analysis yielded three significant factors, explaining 68.96% variation, highlighting geogenic and anthropogenic influences on groundwater chemistry. Hierarchical cluster analysis categorized groundwater into three clusters based on the parameters with similar trends of variation. Furthermore, Discriminant analysis identified four significant variables (Mg2+, F−, Cl− and NO3−) responsible for creating the distinction among the identified clusters. Hydrogeochemical categorization and multivariate statistical analyses indicated that rock–water interaction, weathering, leaching and anthropogenic activities collectively influenced groundwater quality throughout the studied region. The Water Quality Index reveals that 59% of samples have good water quality, while 41% exhibit poor quality predominantly concentrated in the south-western, south-eastern and central regions. This study demonstrates the efficacy of statistical techniques to interpret complex datasets and grasp water quality dynamics, enhancing groundwater management.

Pollution-source fractionation and quantification-based assessment of surface water quality in Saigon River, Vietnam: implications for sustainable management strategies

ABSTRACT The current study fractionated pollution sources and investigated the impacts of seasonal and tidal variations on Saigon River’s surface water quality. Ninety-six water samples were collected across dry and rainy seasons, covering ebb and flood tides, and analysed for 19 parameters. During the dry season, ebb tide showed higher levels of electrical conductivity, sulfate, chloride, sodium, and potassium. During the rainy season, ebb tide exhibited greater concentrations of ammonium, total nitrogen, and phosphorus. The water quality index was significantly lower during the dry season’s ebb tide compared to the flood tide but remained similar in both tidal phases during the rainy season. Four primary pollution sources were quantified, with seawater intrusion and agricultural activities contributing 62.68% and 28.54%, respectively, to water quality degradation. Briefly, the river’s surface water quality was inferior during the dry season compared to the rainy season, primarily due to seawater intrusion and agricultural activities, requiring remediation.

Drinking Water Quality in Delta and Non-Delta Counties along the Mississippi River

The Mississippi Delta region has worse population health outcomes, including higher overall cardiovascular and infant mortality rates. Water quality has yet to be considered as a factor in these health disparities. The objective of this paper is to determine overall differences in basic water quality indicators, electrolytes of cardiovascular importance, trace elements, heavy metals, and radioactive ions of groundwater in delta and non-delta counties in states along the Mississippi River. Data were sourced from the major-ions dataset of the U.S. Geological Survey. We used the Wilcoxon rank sum test to determine the difference in water quality parameters. Overall, delta counties had lower total dissolved solids (TDS) (47 and 384 mg/L, p-value < 0.001), calcium (7 and 58 mg/L; p-value < 0.001), magnesium (2 and 22 mg/L; p-value < 0.001), and potassium (1.57 and 1.80 mg/L; p-value < 0.001) and higher sodium (38 mg/L and 22 mg/L; p-value < 0.001) compared to non-delta counties. Overall, there were no statistical differences in trace elements, heavy metals, and radioactive ions across delta versus non-delta counties. These results underscore the need for further epidemiological studies to understand if worse health outcomes in delta counties could be partially explained by these parameters.

Applying the water quality indices and geographic information system approach to assessing the suitability of groundwater quality for drinking and irrigation purposes in the semi-arid region of Tebessa-Ain Chabro, Northeastern Algeria

Assessing the groundwater quality is important for the efficient exploitation of water resources in semi-arid areas. The study area in northeast Algeria mostly depends on groundwater as its main source of water, and the quality of groundwater is becoming important due to the increasing need for freshwater. The hydrochemical characteristics and water quality of groundwater in the Tebessa-Ain Chabro were assessed using water quality indices, geochemical modeling, and multivariate statistical approaches. The study discovered that the groundwater samples could be classified into four distinct water groups using hierarchical cluster analysis in Q mode (HCA) based on their electrical conductivity. We identified three forms of water: mixed (Ca2+–Mg2+–Cl−), Na+–K+–HCO3−, and Ca2+–Cl−. According to the water quality assessment, only 38% of the samples were deemed suitable for human consumption, while 34% were categorized as poor water, 10% as extremely poor, and 17% as unsafe for drinking. The irrigation water quality index identified four classifications: low, moderate, high, and severe restriction, with corresponding percentages of 31%, 31%, 7%, and 31%. The nitrate pollution index (NPI) showed that 48% of samples fell into the moderate pollution class. Human activity, such as sewage infiltration and waste disposal in open areas, was the cause of this nitrate contamination. The saturation index values showed that groundwater was less saturated in halite and sylvite and more saturated in aragonite, calcite, dolomite, anhydrite, gypsum, and hydroxyapatite. The Tebessa region’s groundwater’s hydrochemical properties and water quality have been assessed using multivariate statistical techniques, geochemical modeling, and water quality indexes. The study’s conclusions can provide a foundation for upcoming research evaluating the region’s groundwater quality.

Water quality index of selected borehole locations in Jos North LGA of Plateau State, Nigeria

Prevalence of water borne diseases is a public health concern. The study assessed the quality of selected borehole waters in Jos North for their potability. The physicochemical parameters were assessed in addition to chlorides, phosphates, nitrates, and sulphates, total solids, total dissolved solids, total suspended solids, total hardness, using standard methods. Atomic absorption spectrophotometry used for elemental analysis of samples for manganese, lead, cadmium, copper and zinc. microbial analysis was carried out to test for presence of anaerobic bacteria, coliforms, Escherichia coli, Salmonella typhi, yeast and mould, Staphylococcus aureus using the plate count method. Water Quality Index by Weighted Arithmetic Index Method. Results ranged from 22.19-56.22 mg/L (chlorides), 0.00-0.07 mg/L (phosphates), 0.11-0.19 mS/cm (conductivity), 141.40-169.40 mg/L (alkalinity) and 86.70-160 mg/L (TSS). Kyan Primary school had Mn 0.632 mg/L against 0.500mg/L recommended by WHO. Microbial analysis revealed that Kyan primary school had 1 cfu per 100 mL water for E. coli, Salmonella typhi, yeast and mould. This indicated faecal contamination. The WQI revealed Village hostel, Kyan Village, Gadabiu had values of 6.54, 19.41, 10.97 are potable, Government College, Angwan Jarawa, Kyan Primary school had 28.90, 61.50, 93.60 are potable, poor, very poor, not potable.

Distribution and ecological health risk assessment of heavy metals in damietta branch of Nile River, Egypt

ABSTRACT The Nile River is one of the longest rivers in the world, serving as the lifeline of many countries. The river is subjected to significant anthropogenic pressures, and thus, understanding the magnitude of contamination and its possible consequences is needed. This research aimed to evaluate the presence of heavy metals in the surface water of an understudied region within the Nile River. The distribution and level of 18 elements along the Damietta branch were assessed, and their potential sources were estimated. Additionally, pollution indices and health risks were calculated. The results showed that most metals were within the acceptable levels of USEPA and WHO. However, Na, Mg, and Ca were higher than the permissible level of WHO, and K was higher than the permissible levels for irrigation. Furthermore, heavy metal pollution indicators, degree of contamination indices, heavy metal evaluation indices, Nemerow pollution indices, and water quality indices all pointed to very high standards for water quality. Also, the noncarcinogenic health risk index indicated a safe limit for dermal and oral exposure for adults and children. Overall, this study recommends management focus on anthropogenic activities in the Damietta branch of the Nile River.

From Transformation to Life Cycle Assessment of Biochar: A Case Study of Wheat Straw Biochar.

Biochar, as a carbon-rich material, exhibits significant potential for industrial applications. While numerous research endeavors have focused on its interactions within soil ecosystems, scant attention has been given to its behavior and potential impact on aquatic environments. In this study, we conducted an investigation to compare the environmental implications of pristine biochar with those of aged biochar. Initially, we assessed the interaction between biochar and key water quality indicators, revealing the release of endogenous ions (e.g., NH4+, NO3-, PO43-, Cu2+, and Cd2+) as well as organic substances (e.g., DOC) from both pristine and aged biochar samples. Aged biochar released higher amounts of ions and organic substances than pristine biochar due to the change in the structure and properties of aged biochar. Environmental risk and toxicity of pristine and aged biochar were subsequently evaluated using the potential ecological risk index (RI) and the impact on growth of Chlorella vulgaris, respectively. The values of RI for Cu indicated a very low degree of environmental risk, while those for Cd were dependent on water quality for surface water. Our study provided thorough analysis on the environmental assessment of biochar by combining experimental environmental transformation and life cycle assessment (LCA) analysis, suggesting biochar could have excellent environmental applications.

Analyzing spatio-temporal dynamics of dissolved oxygen for the River Thames using superstatistical methods and machine learning

By employing superstatistical methods and machine learning, we analyze time series data of water quality indicators for the River Thames (UK). The indicators analyzed include dissolved oxygen, temperature, electrical conductivity, pH, ammonium, turbidity, and rainfall, with a specific focus on the dynamics of dissolved oxygen. After detrending, the probability density functions of dissolved oxygen fluctuations exhibit heavy tails that are effectively modeled using q-Gaussian distributions. Our findings indicate that the multiplicative Empirical Mode Decomposition method stands out as the most effective detrending technique, yielding the highest log-likelihood in nearly all fittings. We also observe that the optimally fitted width parameter of the q-Gaussian shows a negative correlation with the distance to the sea, highlighting the influence of geographical factors on water quality dynamics. In the context of same-time prediction of dissolved oxygen, regression analysis incorporating various water quality indicators and temporal features identify the Light Gradient Boosting Machine as the best model. SHapley Additive exPlanations reveal that temperature, pH, and time of year play crucial roles in the predictions. Furthermore, we use the Transformer, a state-of-the-art machine learning model, to forecast dissolved oxygen concentrations. For long-term forecasting, the Informer model consistently delivers superior performance, achieving the lowest Mean Absolute Error (0.15) and Symmetric Mean Absolute Percentage Error (21.96%) with the 192 historical time steps that we used. This performance is attributed to the Informer’s ProbSparse self-attention mechanism, which allows it to capture long-range dependencies in time-series data more effectively than other machine learning models. It effectively recognizes the half-life cycle of dissolved oxygen, with particular attention to critical periods such as morning to early afternoon, late evening to early morning, and key intervals between the 16th and 26th quarter-hours of the previous half-day. Our findings provide valuable insights for policymakers involved in ecological health assessments, aiding in accurate predictions of river water quality and the maintenance of healthy aquatic ecosystems.

Investigation of hydrochemical characteristic, water quality and associated health risks of metals and metalloids in water resources in the vicinity of Akamkpa quarry district, southeastern, Nigeria

Quarrying of rock aggregates generates produced water that, if not handled properly will be a source of pollution for nearby water bodies, thus affecting the chemistry of the water. This study examined the chemistry, impact of quarrying activities on water resources and the health consequences/risks posed by ingestion of the water by humans in the Akamkpa quarry region in southeastern Nigeria. Thirty (30) water samples consisting of pond water, stream water, hand dug wells, and borehole samples were collected and analyzed for their physicochemical parameters using standard methods. The results obtained from the analyses indicated that the water was moderately acidic, fresh, and not salty, with many parameters below the recommended standards with Ca2+, and HCO3− being the dominant ions present in the water resources. Rock weathering processes including silicate weathering as illustrated by hydrochemical facies, cross plots, and Gibbs diagrams are the dominant mechanisms influencing the quality and major ions chemistry of the water resources with minor contributions from dissolution, anthropogenic activities, and ion exchange. Ca-Mg-SO4-Cl and Na–K-HCO3− are the most important water types. Although the water quality index shows that the water is suitable for human use and irrigation, the mean values of As, Cd, Pb, and Se are above the acceptable limits. Additionally, the calculated contamination factor revealed the water resources are moderate to highly contaminated by As, Cd, Cr, Mo, Pb, Sb, and Se, and are therefore unsuitable for consumption with regards to these parameters. However, the residual sodium carbonate and water hazard index (WHI) values showed that 38% to 90% of sites in the quarry area were unsuitable for cultivation, 10–30% were in the low to medium impact category, and 60% were classified as risky and are from high to very high impact category. A non-cancer study of inhabitants living in the vicinity of the quarry area indicated that 6.7% of the sites have values greater than one, indicating that it may endanger the health of the people. Therefore, constant monitoring of the water quality is recommended as long-term use of contaminated water can harm humans, plants, and soils.

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

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

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

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

Ecological restoration amplifies riverine fish catch of Gudusia chapra (Hamilton, 1822): an impact study in the river Ganga using multivariate statistical tools and water quality indices.

Fish residing in the aquatic ecosystem are considered the best ecological indicator for monitoring environmental habitat. To evaluate the changes that occurred due to relative restoration in the ecological habitat, a study was conducted in the freshwater zone of the river Ganga between Buxar, Bihar, and Ballia, Uttar Pradesh, between July 2021 and July 2022. In the monitoring, the physico-chemical condition, as well as the food and feeding habits of the fish Gudusia chapra, were monitored with the help of various pollution evaluating indices, namely, the algal pollution index (API) for planktons, the comprehensive pollution index (CPI-WQI), and the National Sanitation Foundation Water Quality Indices (NSF-WQI) for water. The study showed that the relative restoration facilitated the amplification of the fish catch from 5.60 to 98.98% in two consecutive years. The reduction in the API (15 to 4) as well as CPI (0.80 to 0.72) during both years signified the reduction of the pollution status of the river in the region. The NSF-WQI also decreased from 88.27 to 79.27 from 2021 to 2022. The electivity index for the fish showed that fish preferred the groups Cyanobacteria, Rotifera, and Copepoda. The multivariate, as well as univariate analyses, revealed that the fish G. chapra is significantly influenced by multiple abiotic as well as biotic variables, among which the major contributors are riverine velocity, transparency, conductivity, pH, dissolved oxygen, total alkalinity, carbonate, bicarbonate, salinity, total hardness, calcium, silicate, and biochemical oxygen demand.

Integrated Geospatial and Geostatistical Multi-Criteria Evaluation of Urban Groundwater Quality Using Water Quality Indices

Groundwater contamination poses a severe public health risk in Lahore, Pakistan’s second-largest city, where over-exploited aquifers are the primary municipal and domestic water supply source. This study presents the first comprehensive district-wide assessment of groundwater quality across Lahore using an innovative integrated approach combining geographic information systems (GIS), multi-criteria decision analysis (MCDA), and water quality indexing techniques. The core objectives were to map the spatial distributions of critical pollutants like arsenic, model their impacts on overall potability, and evaluate targeted remediation scenarios. The analytic hierarchy process (AHP) methodology was applied to derive weights for the relative importance of diverse water quality parameters based on expert judgments. Arsenic received the highest priority weight (0.28), followed by total dissolved solids (0.22) and hardness (0.15), reflecting their significance as health hazards. Weighted overlay analysis in GIS delineated localized quality hotspots, unveiling severely degraded areas with very poor index values (>150) in urban industrial zones like Lahore Cantt, Model Town, and parts of Lahore City. This corroborates reports of unregulated industrial effluent discharges contributing to aquifer pollution. Prospective improvement scenarios projected that reducing heavy metals like arsenic by 30% could enhance quality indices by up to 20.71% in critically degraded localities like Shalimar. Simulating advanced multi-barrier water treatment processes showcased an over 95% potential reduction in arsenic levels, indicating the requirement for deploying advanced oxidation and filtration infrastructure aligned with local contaminant profiles. The integrated decision support tool enables the visualization of complex contamination patterns, evaluation of remediation options, and prioritizing risk-mitigation investments based on the spatial distribution of hazard exposures. This framework equips urban planners and utilities with critical insights for developing targeted groundwater quality restoration policies through strategic interventions encompassing treatment facilities, drainage infrastructure improvements, and pollutant discharge regulations. Its replicability across other regions allows for tackling widespread groundwater contamination challenges through robust data synthesis and quantitative scenario modeling capabilities.

Algal diversity and its relationship with seasonal variation of water quality in Gajedi Lake, Rupandehi District (Nepal)

The current study focuses on the algal diversity of Gajedi Lake in different seasons in connection to the lake's water quality indicators. Algae and water samples were collected from eight peripheral sites of the lake in summer, rainy, and winter seasons in 2021. The water temperature, conductivity, total dissolved solids, hardness, alkalinity, phosphorus, free CO2, and dissolved oxygen were recorded as high during the summer season while water pH was high during the rainy season. Altogether 93 species of algae were reported under 52 genera, 30 families, 7 classes and 6 phyla in this study. The largest phylum was Bacillariophyta (44.08%) followed by Chlorophyta (17.20%), Euglenozoa (10.97%), Cyanobacteria (12.90%), Charophyta (10.75%) and Miozoa (1.07%). The Shannon-Weiner diversity index indicated high abundance during the summer season, with more evenly distributed algal species. More algal species were recorded in the winter season. Trachelomonas, Navicula, and Nitzschia were dominant genera during summer; Anagostidinema, Desmodesmus, and Pinnularia were dominant during rainy; and Trachelomonas, Tetradesmus, and Gomphonema were dominant during winter. The redundancy analysis ordination showed that the algal composition varied along with the seasonal changes in physico-chemical parameters. Temperature, pH, and conductivity were thus identified as significant factors influencing species richness.

Water Quality Evaluation and Spatial-temporal Distribution Characteristics of the East Route of the South-to-North Water Diversion Project in Jiangsu Province Based on WQI

The east route of the South-to-North Water Diversion Project in Jiangsu Province was used as an example to investigate the characteristics of changes in water quality in the area affected by significant water diversion projects. Based on the comprehensive assessment method of the water quality index （WQI）, the M-K trend test, and the geographic information system （GIS）, the spatial and temporal variation characteristics of water quality in the 13 national assessment sections of the east route of the South-to-North Water Diversion Project in Jiangsu Province were evaluated and analyzed from 2013 to 2022. The results showed that the water quality assessment grades in the study area were mainly "medium" and "good." The overall mean value was 74.03, indicating "good" water quality. DO, BOD5, and NH4+-N were the primary indicators of changes in river water quality in the region. Over time, the water quality in the basin had significantly improved from 2013 to 2022. However, there was a rebound in 2021, but this phenomenon was effectively controlled in 2022. Water quality was better during the non-flood season compared to that during the flood season. From a spatial perspective, the water quality in the southern part of the region was superior to that in the north. Furthermore, the rate of improvement was faster in the south. This could be attributed to factors such as precipitation, population density, and the scale of agricultural and livestock activities. However, the water quality of the S11 （Sanduoxi Bridge） section was generally lower than that of other sections and should be given further attention.

Impacts of fish pond effluent on the water quality of an afrotropical stream: a comprehensive evaluation using the water quality index

This study highlights the importance of managing fishpond effluent to minimize its impact on aquatic environments. Fish effluents are a major concern worldwide in aquatic environments. It also provides information on the impacts of effluents on the water quality index of streams when released into aquatic environments. Streams and fishponds were sampled bimonthly for two annual cycles, covering different sampling stations both upstream and downstream of the fishpond effluents at 50-m intervals. Water quality parameters associated with in situ conditions were determined in the field. In the laboratory, other physicochemical parameters were determined via proper standard protocols. The results of the study revealed that water quality parameters such as turbidity, total suspended solids, total solids, conductivity, total dissolved solids, dissolved oxygen, biological oxygen demand and organic matter recorded in water samples collected from 50 m upstream at the point of effluent discharge were significantly (p < 0.05) different from those recorded at other sampling stations. The WQI value of the discharge point was higher than the WQI recorded in both the upstream and downstream sections of the stream. The findings of this study showed that the point of discharge of fishpond effluents is particularly concerning for the receiving stream compared with other sampling points. This localized area has experienced marked deterioration in water quality, posing significant threats to the health and biodiversity of aquatic ecosystems. The effluent's impact, though slight when dispersed in the receiving waterbody, underscores the necessity for adequate management practices to mitigate its adverse effects. Effective strategies, including regular monitoring, effluent treatment, and sustainable pond management, are imperative to ensure the long-term health and resilience of the aquatic environment.

Hydrogeochemical evaluation of groundwater evolution and quality in some Voltaian aquifers of Kintampo South District, Bono East Region, Ghana: Implications from chemometric analysis, geochemical modeling and geospatial mapping techniques

Kintampo South District in the Bono East Region of Ghana is dominated by metavolcanic and metasedimentary rocks of the Birimian and the Voltaian Supergroups, which are reported to show aquifer complexities and quality issues. Therefore, assessment of groundwater evolution and quality is important in this area because of the growing need for groundwater for both agricultural and residential use. The people heavily rely on agriculture as their main source of livelihood, and the agricultural practices could potentially impact the groundwater quality. Consequently, this research aimed to evaluate groundwater appropriateness in the Voltaian aquifers of the Kintampo South District for irrigation and consumption. Irrigation water quality indices, geochemical modeling, hydrochemical graphing, and chemometric analysis were all used in the assessment. The investigation reported potassium ion (K+) as the principal cation in the groundwater, showing concentrations within the range of 0.200 to 61.0 mg/L and a mean of 6.32 mg/L. Bicarbonate (HCO3−) is also the major anion in the samples with values that vary from 2.00 to 238 mg/L and a mean of 27.8 mg/L. Geospatial mapping indicates that these predominant ions show higher concentrations in the central part of the study area. Groundwater evolved from K-SO4-HCO3 to Na-HCO3-Cl water types and other mixed forms, which are influenced by atmospheric precipitation and rock weathering. Geochemical modeling reveals that undersaturation of the groundwater occurs in relation to all the silicate and carbonate minerals in the aquifer. However, most samples show positive correlation with these minerals, suggesting precipitation under pre-existing conditions. Chemometric analysis indicated that the chemical composition of groundwater is controlled by human-induced and geogenic activities. With respect to all hydrochemical parameters, the groundwater is largely deemed safe for residential use based on the computed Water Quality Index values. The groundwater in the district is also appropriate for irrigation, according to irrigation indices of water quality such as the Wilcox diagram, sodium adsorption ratio (SAR), Electrical conductivity (EC), magnesium ratio (MR), and sodium percent (Na%).

Long-term monitoring of water quality and phytoplankton community structure of Lake Manzala, Mediterranean Coast of Egypt

Coastal wetlands play a crucial role in supporting biodiversity, providing valuable ecosystem services, and contributing to the resilience of coastal ecosystems, making the preservation and restoration of these wetlands essential for sustainable development in coastal regions. This study focuses on Lake Manzala, a coastal wetland located on the Mediterranean Coast of Egypt, highlighting the significance of conserving and managing this unique environment. The objective of this research was to evaluate the water quality and phytoplankton structure of Lake Manzala and establish an updated long-term ecological database for the region, specifically evaluating the effectiveness of development plans that were carried out in 2017. Surface water samples were collected seasonally at eleven sites between 2010 to 2022. The findings revealed that prior to the development plans, the phytoplankton abundance in Lake Manzala exhibited high levels of eutrophication, characterized by increased abundance and species richness. The dominant phytoplankton classes in Lake Manzala were Bacillariophyceae, Chlorophyceae, and Cyanophyceae. Prior to development plans, they accounted for 46.5% and 45.0% respectively. Post-development, Bacillariophyceae increased to 62.8%, while Chlorophyceae decreased to 25.1%. Dinophyceae increased from 1.3% to 9.04%, while Cyanophyceae decreased from 6.1% to 1.6%. Based on the Trophic State Index for chlorophyll a, Lake Manzala underwent a shift from predominantly hypertrophic to eutrophic conditions. The study explored the relationship between biological factors and environmental conditions using principal component analysis, cluster analysis, and the modified water quality index (WQI). The results indicated positive signs of improvement in Lake Manzala during the post-development phase, as it transitioned from a poor to a moderate state. This research emphasizes the need for integrated land and water management approaches. By informing policy direction and development, this research underscores the importance of preserving and restoring ecosystems for the long-term well-being of both local communities and the global environment.

Comparative Analysis of Water Quality Index (WQI) from Selected Water Bodies in Different Regions of Southeast Nigeria

This study was carried out to compare the water quality index of selected water bodies in Okigwe, Imo State, Nigeria. Water samples were collected from two streams, Ihiku and Iyiechu (upstream and downstream) and the experimental research was used for this study. Several physico-chemical characteristics were analyzed in line with W.H.O, USEPA, S.O.N. The results obtained from the physico- chemical parameters ranged as follows: air shade temperature (23.3-25.0), pH (5.7-6.8), Electrical conductivity (15.5-20.4), Total hardness (33-40.5), Alkalinity (55.5-70.8), Biological Oxygen Demand (2.6-5.0), Dissolved Oxygen (6.5-8.0), Sulphate (1.8-5.7), phosphate (5.2-7.0) and silica (0.66-0.78). The result showed that there were variations in the concentration as a result of anthropogenic activities of man. The water quality index was also checked and compared to standards. The Pearson’s Correlation Moment was performed at 0.01% level. The result showed that values obtained were statistically significant. However, adequate treatment facilities that purify sewage prior to discharge or disposal should be adopted.