WQI Values Research Articles

Study Assessment of Soil and Water Quality Conditions on Barren Agricultural Lands in Tropical Regions

Barren land is non-productive land that is difficult to use as a medium for integrated agricultural cultivation. The aim of this research is to determine the profile and feasibility status of land in barren agricultural areas quantitatively. The research method used was descriptive with purposive data collection. Data analysis included SQI and WQI parametric analyses. The research results indicate that the ideal soil parameter is only pH 7.5-7.7, while for water parameters it is pH 8.0-8.1, meeting water quality standards. SQI values range from 0.44 to 0.49 and WQI from 0.45 to 0.57. SQI and WQI values at the research site fall into the poor category, indicating difficulty in converting the land into agricultural use. SQI and WQI show a strong correlation as depicted in the model Y = 4.113 + 0.026 (R2 = 0.789). Correlation tests showed strong correlations in soil between redox potential and soil pH (0.449), and redox potential and organic matter (0.377). Weak correlations were found between cation exchange capacity and soil pH (0.009), and nitrate and total N (0.517). In water, strong correlations were found between water pH and nitrite (0.302) and ammonia (0.529). Additionally, water pH showed weak correlations with carbon dioxide (0.752) and organic matter (0.659). The values of soil and water parameters have an immediate impact on plant growth patterns. Therefore, integrated agricultural cultivation patterns need to be developed. In conclusion, empirically, the condition of barren land indicates poor land use feasibility. The poor profile and biophysical feasibility conditions of barren land are attributed to environmental pollution and runoff from other land areas.

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.

GIS-Based Mapping of the Water Quality and Geochemical Assessment of the Ionic Behavior in the Groundwater Aquifers of Middle Ganga Basin, Patna, India

The study implemented Geographic Information System (GIS) techniques and multivariate hydrogeochemical analysis to evaluate the spatial-temporal and seasonal variation in the groundwater quality of Patna, India. For this purpose, sixty groundwater samples were collected and analyzed for major anions and cations during the pre-monsoon, monsoon, and post-monsoon seasons of 2019-2020. The physicochemical parameters such as pH, EC (Electrical Conductivity), TDS (Total Dissolved Solids), TH (Total Hardness), Ca2+, Mg2+, Na+, K+, HCO3-, Cl-, SO42- were considered to evaluate the water quality index. The result revealed degradation in groundwater quality from pre-monsoon (49.21) to post-monsoon (74.48). EC, TDS, TH, Mg2+, Na+, Ca2+, K+, and HCO3- ions were found accountable for high WQI values at various sampling sites during different seasons. Spatial maps showed that 45 % of the sampling stations exhibited poor quality in all three seasons, where the eastern part of the studied region was revealed to be the most affected area. The application of multivariate statistical methods and hydrogeochemical investigation has clearly defined the dominant role of the weathering process, and reverse ion exchange mechanism in controlling the aquifer’s ionic chemistry. Moreover, poor seepage system, and waste leachate from the surface have been found as the main cause of high levels of Na+, K+, and Cl- in the eastern part of Patna.

Assessing seasonal changes in water quality using various indices in Chenab River and its tributaries (J&amp;K)

The present study involves the analysis of thirteen physiochemical parameters (pH, temperature, electrical conductivity, total dissolved solids, turbidity, alkalinity, hardness, calcium, magnesium, dissolved oxygen, biological oxygen demand, sulphate and nitrate) and five heavy metals (chromium, zinc, arsenic, lead and cadmium) from Chenab River and its tributaries (Neeru and Bichleri) at Ramban and Doda district, J&amp;K. The analysis was done for two different seasons i.e. summer (June) and winter (December), 2022. The current investigation indicated that all the physiochemical parameters were in the permissible limit in both the seasons except few parameters (Ca, Mg, turbidity). In the analysis of heavy metals in both the seasons, it was found that there was no heavy metal contamination in all sampling sites except the Cr concentration which was found to be higher in all sites (except SXII) in summer season. The detailed analysis involved the calculation of various water quality indices which graded water quality under ‘good’ category as per WQI value whereas CPI and HPI value showed moderate to high pollution level in water during summer season. The study showed the seasonal variation in water quality parameters and thus encourage the need for regular monitoring of water quality to reduce pollution level.

Evaluation of the Water Quality of the Drainage Alhfar in Al-Diwaniyah Governorate According to the Iraqi Guide WQI

A study was conducted on the eastern drainage of the Euphrates River (Alhfar) in Diwaniyah at three stations, summer and winter. The drainage Alhfar was evaluated using the WQI and Was selected 12 parameters, namely (PH, E.C, TDS, Turb., T.H, Cl, Mg, Ca, Zn, Pb, Cu, Cd), From the results, it is noted that the first site recorded (302, 290) in summer and winter, respectively, according to WQI, while the second site recorded (294.5, 298.8) in summer and winter, respectively, The WQI value for the third site was (310 a, 380), according to WQI the water in the first and second sites was very poor water due to the increase in the proportion of determinants. In the third site, the water was unsuitable water because the WQI was very high in summer and winter.

Groundwater quality evaluation for drinking and agricultural purposes. A case study in semi-arid region (Zab El-gharbi SE-Algeria)

The current research delved into the geochemical attributes of groundwater and assessed compliance with drinking water standards. 35 samples of Zab El Gharbi region groundwater in the province of Biskra were analyzed to evaluate the physico-chemical quality. The obtained results were compared to World Health Organization drinking water standards as well as Algerian Standards. It appears that nitrate concentrations in all samples were acceptable since they were less than 50 mg/L. The results of the WQI classification showed that WQI values ranged from 95 to 269; only 3 % of samples had good quality, 80 % had poor quality, and 17.14 % had very poor water, indicating the need for treatment before use for human consumption. Two main hydrochemical facies were dominated and predominated, Ca-SO4 type and Mixed Ca–Mg–Cl-SO4 type, respectively. Q mode hierarchical cluster analysis (HCA) was employed for partitioning the water samples into hydrochemical facies, revealed the presence of two distinct water types based on principal ion concentrations. Hydrochemically, group 1 was characterized by two primary facies, with 90.32 % categorized as Ca-SO4 type and 9.67 % as Mixed Ca-Mg-Cl-SO4 type. While group 2 was characterized by a Ca-SO4 type. The estimated values of sodium adsorption ratio (SAR), percent sodium (Na%), permeability index (PI), Kelly's ratio (KR) and Magnesium hazard (MH), averages for the study area is reported to be in the range of 0.90 to 5.60, 4.46 % to 41.26 %, 12.50 % to 44.47 %, 0.10 to 0.73 % and 9.69 % to 75.06 % respectively. Parameters such as Permeability Index (PI), Kelly's Ratio (KR), and Magnesium Hazard (MH) indicated that 37.14 % of groundwater samples were in the excellent category, while the remaining 62.85 % were in the good category, making them suitable for irrigation across various soil types. They indicated that the considered water exhibits favorable characteristics for agricultural irrigation applications, ranging from excellent to good. These findings are encouraging for agriculture and land-use planning. This study lies in addressing the water quality in this promontory area, where no prior research has been published. We assessed water quality using statistical, geostatistical, and cartographic methods to estimate quality in unsampled areas. Additionally, we examined how climatic conditions, particularly high evapotranspiration during the festive season, affect water and soil quality. This study will help farmers and scientists in the region make informed decisions to protect natural resources. This work is meant to highlight the issues and also provide practical solutions to optimize the management of natural resources.

Environmental assessment of Vaishav stream: a left bank tributary of river Jhelum in Kashmir Himalaya, India

The present study was carried out to assess the environmental impact including water quality parameters of Vaishav stream, one of the left bank tributary of river Jhelum. A detail study of the selected sites was undertaken for the sampling, keeping in mind the topography of the stream i.e. elevations, fast flowing areas, slow zones as well as human interferences. Three sites were selected for study purpose and samples were collected on monthly basis. A total number of 15 parameters were analyzed. Some of the parameters like temperature, pH, TDS, conductivity and 14dissolved oxygen were assessed on spot at sampling sites, while rest of parameters were determined in the laboratory by standard titration methods (APHC 2012). Low DO and higher concentration of pH, CO2, total alkalinity, hardness and nitrate, sulphate, was found at downstream site-III compared to upstream site-I, showing low concentration of these parameters except DO. WQI value varied from 41.50 to177.70 minimum at site-I and maximum at site-III. To quantify the association and co-relationship among various physico-chemical variables, correlation test (Pearson’s correlation coefficient) was carried out. Pearson’s test showed that significant positive correlation exists between pH with total hardness (r= 0.833, p&lt;0.05). The electrical conductivity showed significant positive correlation with TDS (r=1.00, p&lt;0.05), total hardness (r=.897, p&lt;0.05) and sulphate (r=.917, p&lt;0.05). The nitrate shows significant positive correlation with sulphate (r=0.947, p&lt;0.05). The DO shows negative correlation with water temperature (r=-0.396, p&lt;0.05), total alkalinity (r =-0.843, p&lt;0.05) and sulphate (r=-0.902, p&lt;0.05) respectively. Results of ANOVA showed significant level of spatial and temporal variations on the concentrations of water quality parameters (P&lt;0.05, Turkey’s Post Hoc Test) across months at all sampling sites. Therefore, further research is needed to explore the ecological effects of these variations and develop strategies for sustainable water resource management to support ecologists, limnologists, policymakers and other stakeholders in developing long-term management programs and conservation strategies for water resources.

Water quality evaluation based on water quality index and multiple linear regression: A research on Hanyuan Lake in southern Sichuan Province, China.

This study aims to understand the changes in the water quality of Hanyuan Lake and to show these changes over time. In this study, monthly sampling was conducted at three sampling sites in Hanyuan Lake, and water samples were measured for water quality indicators in the laboratory according to the methods specified in the Environmental Quality Standards for Surface Water (GB3838-2002). Based on the monitoring data from January to December 2019, the WQI comprehensive evaluation method was used to conduct multiple linear stepwise regression analysis, extract key indicators, and establish the WQImin model. The results show that according to the WQI comprehensive evaluation method, the WQI values of Hanyuan Lake are all above 90, and the grade is excellent. The overall water quality of Hanyuan Lake is excellent, and most of the water quality indexes reach the Class I standard in the Environmental Quality Standards for Surface Water (GB3838-2002). WQImin1 (R2 = 0.86, p < 0.001, PE = 4.28) as the best WQImin model. In this study, a model with fewer parameters was established by multiple linear regression method, which is conducive to better monitoring of water quality at monitoring stations while saving costs. PRACTITIONER POINTS: According to the WQI comprehensive evaluation method, the WQI values of Hanyuan Lake are all above 90, the rating is excellent. From January 2019 to September 2020, the monthly change trend of each section is roughly the same, showing a trend of first decreasing, then rising, then decreasing, and finally rising and flattening. The WQImin model was developed to completely describe the change in the water body.

Comparative Study of Groundwater Quality for Drinking and Irrigation Purposes in Selected Villages of Manipur, India

A comparative study was done to monitor the groundwater qualities, both for drinking as well as irrigation purposes in some villages of Imphal East district, Manipur, in the period of pre-monsoon and monsoon of 2021. Totally, fifteen (15) groundwater samples were collected and examined for some important parameters like temperature, pH, TDS, TH, TA, Mg2+, K+, HCO3-, Ca2+, CO32-, Na+, Cl-, NO3- and SO42-. The results revealed that all the groundwaters were slightly alkaline in nature and fall under freshwater category. In both the seasons, majority of the parameters for various groundwaters have found their values/ concentrations below its acceptable limits, as given by BIS and WHO. In pre-monsoon, 73.33% of groundwaters were found as ‘moderately hard water’ and 26.67% (hard water) whereas in monsoon, 60% (moderately hard water) and 40% (hard water). Dominant ions in both seasons were Na+ (sodium) and HCO3- (bicarbonate) for cations and anions respectively. In most of the samples of monsoon, values and concentrations of the studied parameters were observed to be greater/higher as compared to that of pre-monsoon. It was mainly due to the leaching out of the soluble salts in the earth’s crust by rainwaters and finally mingled with the groundwater bodies in the aquifers in monsoon season. WQI values showed that in pre-monsoon, 26.67% of groundwaters were found as excellent water, 66.67% (good) and 6.66% (poor) while in monsoon, 60% (good) and 40% (poor). For irrigation water qualities, the indices (RSC, SAR, %Na, PI and KR) were examined. In the overall, all the samples can be utilized for irrigation (agriculture) purposes in both seasons. Correlation co-efficient (r) values showed that in both the seasons, the TH of various groundwaters was mainly because of dissolved sulphates of Ca2+ along with Mg2+.

Impact of industrial hotspots on Tamla nala and Nunia nala confluence - a tributary of the Damodar river.

Clean water is essential for drinking, household use, and agriculture. Researchers studied 39 sites near Tamla nala and Nunia nala channels in Durgapur and Asansol City (West Bengal) to assess the deterioration level of water due to industrial discharge. During the first phase out of three, the researchers conducted a spatial representation of various physicochemical parameters, such as temperature, pH, Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Total Hardness (TH), Electrical Conductivity (EC), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), significant anions such as chloride (Cl-), nitrate (NO3-), phosphate (PO4-3), sulfate (SO42-), cyanide (CN-1) and fluoride (F-), as well as heavy metals/metalloids such as lead (Pb), cadmium (Cd), chromium (Cr), iron (Fe), copper (Cu), nickel (Ni), mercury (Hg) and arsenic (As). As observed the parameters at various sites along the stream exceeded threshold limits majorly due to industrial discharge: highest pH, TDS, TH, EC, Cl-, SO42- at site 26; Fe at site 1, TSS, COD, CN- at site 33, 31, 2 respectively; Cd, Ni, Cu at site 19; Hg and Pb at site 3 and As at site 20. Contaminated areas were marked in red and secure areas in green. Additionally, the HMPI (Heavy metal pollution index) was estimated for eight locations to understand the impact of heavy metal pollution in the second phase of the study. An extremely high HMPI indicates heightened toxicity and health risks for both residents and outsiders. The Canadian Water Quality Index (1.0) was calculated for eight sites in the third phase based on seventeen parameters. The resulting WQI value was below 44, indicating poor water quality at the sites. Due to the poor quality and critical heavy metal toxicity, the authors recommended continuous monitoring, strict regulation enforcement, increased treatment capacity, Zero Liquid Discharge implementation, and raising awareness among residents.

Assessment of Surface Water Quality Using Entropy-WQI, Fuzzy-TOPSIS Analysis, Irrigation Indices and Spatial Interpolation Approaches in Mahanadi River Basin, Odisha, India

The current study is aimed at the assessment of surface water quality in the Mahanadi River, Odisha and its suitability for agricultural and consumption purposes, utilizing various indices of water quality such as Entropy Water Quality Index, Osmotic Pressure, Potential Salinity, Residual Sodium Carbonate, Sodium Adsorption Ratio and Kelly Index. Multi-criteria decision-making (MCDM) mechanisms namely, fuzzy-TOPSIS modeling and GIS tools were used; additionally, the suitability of river water for industrial uses was evaluated using indices such as Ryznar Stability Index and Puckorius scaling index. From 2019 to 2023, samples from 19 sampling stations were collected and 21 physical and chemical parameters were evaluated and compared with the normative recommendations advised by WHO. The dispersion of surface water quality on land use changes was discovered using GIS approaches. Additionally, using ArcGIS software, the spatial variability of hydrological processes was determined using the IDW interpolation approach. The pH levels of certain sampling points were slightly above the acceptable limit. Tests revealed that the Total coliform (TC) and turbidity levels in the water samples exceeded critical limits, particularly in areas of the urban river basin that were irrigated with wastewater. The calculated values of EWQI lie between 14.6 and 1066. Entropy WQI values designated 2 locations (ST-8, 19) out of 19 sampling locations as poor category and another one testing point (ST-9) as extremely poor category. The study found that 84.21% of the water samples were of excellent quality for drinking, while 15.78% of locations had poor or extremely poor water quality. However, some indices were favorable for the usage of the water for irrigation purposes. Magnesium hazard (MH) readings at two sampling sites were above 50%, indicating that they were inappropriate for irrigation. USSL (United States Salinity Laboratory) diagrams categorized the water samples as C1-S1 (low salinity and low sodium) for almost 18 sites and C4-S3 (very high salinity and high sodium) for only ONE sample, respectively, suggesting river water’s irrigation suitability. Further, Piper diagrams revealed that most investigated waters were Ca2+-Mg2+-Cl- water type. In a later stage, from Gibb’s diagram, it was found that most samples fall under the rock-water dominance. Based on the above and all other investigation results, it was concluded that water is suitable for irrigation and drinking purposes in all sites, except for three locations. The reason may be due to long-term use of wastewater, anthropogenic activities, over-extraction of surface water and changes in land use patterns. To sum up, it is advantageous to combine physicochemical properties, EWQI, fuzzy-TOPSIS, and GIS tools to evaluate surface water suitability for consumption and agriculture and their regulating variables. The strategy utilized in this work will aid the water management authorities in ensuring the supply of safe water for stakeholders.

Water quality assessment and evaluation of human health risks in the Pusur River, Klaten Regency, Central Java, Indonesia.

This research examines the condition of the water characteristics of the Pusur River to provide data regarding water quality status and risks to human health. In determining the water quality use the NSF-WQI, or National Sanitation Foundation-Water Quality Index based on the main water quality parameters, including temperature, fecal coliform, turbidity, pH, DO, COD, and nitrate. The WQI at the Sudimoro Village location is 37.50, Cokro is 43.54, Wangen is 39.51, Delanggu is 35.45, Juwiring is 38.05, and Taji Village is 34.92. From these six locations, the WQI values are all included in the bad criteria (scores of 26-50). The low WQI values at the six locations were influenced by the low values of the DO, nitrate, temperature, and fecal coliform sub-indices. This low value is related to anthropogenic activities in the region. Furthermore, the data were subjected to applications of the Chronic Daily Index (CDI) Hazard Quotient (HQ), and Hazard Index (HI) to reveal possible non-carcinogenic health risks from nitrate and cadmium contaminants. The hazard quotient through exposure to ingestion from each sampling point includes low risk, namely the value range of 0.1 < HI < 1 for adults and children. Water from rivers must be adequately treated before being used for domestic purposes.

Studies on groundwater quality index around industrial areas of low hills in Himachal Pradesh

The present study emphasizes on groundwater quality assessment and working out the interrelationship between various physico-chemical parameters and potentially toxic elements in low-hills of Himachal Pradesh. The study was conducted in industrial areas of two districts and a total of 240 groundwater samples were collected during 2020-2022 from borewells and handpumps and analyzed 21 parameters such as temperature, turbidity, TDS, EC, pH, DO, BOD, alkalinity, sulphate, nitrate, sodium, calcium, total hardness, chloride, magnesium, manganese, iron, zinc, copper, chromium, and lead. The study area was divided into five locations in both the districts and samples were taken during pre-monsoon and postmonsoon to check the seasonal variation. The estimated values were then compared with drinking water quality standards prescribed by BIS and location-wise WQI value was calculated. The results showed that in both the districts, the physico-chemical parameters under study were within the permissible limits. The WQI values range from 43.85 to 25.85 in district Sirmaur and 39.18 to 25.60 in district Una. In both the districts, the WQI lies under the good to excellent category and were suitable for human consumption. Location-wise, the highest WQI value was highest around the industries followed by samples within the industry &gt; along the main highway &gt; residential areas, and the lowest value was in the control which was the samples taken from the Department of Irrigation and Public Health supply. Seasonal-wise, the concentration of the physico-chemical parameters as well as the WQI was higher during post-monsoon than pre-monsoon.

Application of Principal Component Analysis in Establishing the Dominant Pollutants in the New Calabar River.

The New Calabar River, an essential water source in Nigeria’s Niger Delta region, is facing significant water quality issues due to human activities. This research adopts a comprehensive strategy, integrating field data gathering, statistical analyses, and modeling methods to evaluate and simulate the impact of these activities on water quality. Analysis of Variance (ANOVA) outcomes revealed notable seasonal fluctuations in certain water quality parameters like Water Temperature (F=116.009, p&lt;0.001) and pH levels (F=12.782, p&lt;0.001), indicating clear distinctions between the specified months. Conversely, Total Dissolved Solids (TDS) and Electrical Conductivity (EC) showed insignificant variations (F=0.050, p=0.95 and F=0.036, p=0.96, respectively). Principal Component Analysis (PCA) identified crucial factors influencing water quality variations. The rotated component matrix displayed substantial loadings for parameters such as Turbidity (0.932), Dissolved Oxygen (0.919), and Biological Oxygen Demand (0.912), suggesting their significant impact on water quality dynamics. Employing GIS techniques for spatial mapping of WQI values uncovered pollution hotspots near Points 5 and 6, aligning with the PCA findings. These regions exhibited “Very Bad” water quality status, indicating severe pollution levels. Conversely, Point 3 demonstrated a “Medium” water quality status, implying better water quality conditions. Overall, the study highlights the intricate connection between human activities and water quality in the New Calabar River. The insights gained offer valuable guidance for informed decision-making in water resource management, pollution mitigation strategies, and policy development. Future research endeavors should prioritize continuous monitoring, adaptive management approaches, and community involvement to foster sustainable water quality management practices in the area.

ASSESSMENT OF GROUNDWATER QUALITIES IN SOME VILLAGES OF CHURACHANDPUR DISTRICT OF MANIPUR, INDIA FOR DRINKING AND IRRIGATION PURPOSES

Groundwater is the main source of water for drinking as well as irrigation purposes for the local people in some villages of Churachandpur district of Manipur, India. Twenty (20) groundwater samples (dug well) were collected from three (3) villages of Churachandpur district during the period of pre-monsoon (2019) and they were examined for some important physico-chemical parameters like temperature (°C), total alkalinity (TA), pH, total hardness (TH), TDS (total dissolved solids), Ca2+ (calcium), K+ (potassium), CO3 2- (carbonate), Mg2+ (magnesium), Cl- (chloride), Na+ (sodium), SO4 2- (sulfate) and HCO3 - (bicarbonate). Study data revealed that the majority of the studied parameters for different groundwater possessed their values and concentrations within/below their corresponding desirable limits of BIS and WHO. Ca2+ and HCO3 - were recorded as the dominant ions among the cations and anions respectively. WQI values confirmed that the majority of the groundwater fall under ‘excellent’ to ‘good water’ category and was fit for drinking purposes. RSC, SAR, and %Na showed that all analysed 20 samples were observed as ‘fit’ for irrigation (agricultural) purposes. Correlation coefficient (r) values proved that TA of the different groundwater was mainly because of dissolved Ca(HCO3)2, NaHCO3, and Mg(HCO3)2 whereas, TH of different groundwater was mainly because of temporary hardness, possessed by the presence of dissolved bicarbonates of calcium, sodium, and magnesium but permanent hardness contribute to a lesser extent.

Comparative Study of Drinking Water of Three Different Schools of Damak, Jhapa

The health and well-being of society are measured by the quality of the water. Thus, it is the most important issues facing the entire planet today. The main aim of the work is to evaluate the WQI of three different school to check the quality of drinking water. The WQI value for Singha Devi Secondary, Oxford English and Himjyoti English are 45.36, 36.73 and 64.69 respectively. The water of Singha Devi and Oxford falls in good category whereas water of Himjyoti falls in poor category.Which shows that groundwater of Himjyoti is relatively contaminated. All these three waters are suitable for drinking, but certain treatment is required to retain their quality.

Hydrogeochemical evolution of groundwater impacted by acid mine drainage (AMD) from polymetallic mining areas (South China)

Mining activities have long-term impacts on the groundwater of surrounding areas and deserve in-depth analysis and study. Herein, the geochemical mechanisms of acid mine drainage (AMD)-affected groundwaters were examined, and groundwater quality was assessed through water quality indices. 15 water samples from 7 domestic and 4 groundwater monitoring wells were tested for physical and chemical parameters in 2022, and multivariate statistical analysis was carried out with monitoring data from 21 domestic wells in 2010. The groundwater chemical composition varied from a predominantly Ca-HCO3 type in 2010 to a Ca-SO4 type in 2022. The isotopic values of δ18O and δD indicate that groundwater has not been significantly affected by evaporation. Changes in groundwater sulfate and total dissolved solids (TDS) levels over the twelve-year period confirmed the AMD infiltration impact on groundwater quality. The groundwater chemical properties changed more slowly than those of surface waters affected by AMD based on a cumulative increase in sulfate concentration of 29.94 mg/L. Changes in groundwater quality were investigated, namely, the spatiotemporal distribution of potentially toxic elements (PTEs), including Fe, Mn, Cd, Pb, and As. Mn concentrations in upstream groundwater areas near the mine decreased by 61.8% between 2010 and 2022. Conversely, groundwater in midstream areas had Mn concentrations of 2.25 mg/L and arsenic concentrations of 11.8 μg/L, both exceeding the WHO, 2022 standard. According to multivariate statistical analysis, Mn, Cd, and Pb originated from polymetallic minerals, whereas As was likely derived from the reduction of Fe/Mn hydroxyl oxides. AMD remediation improved contaminated upstream groundwater quality over 12 years, with a 36.8% improvement in WQI values. PTE distribution determined water quality changes; therefore, PTE contamination should be treated in mid- and downstream regions while contaminated groundwater should be treated upstream.

Potential Impacts of Climate Change on Reservoir Water Quality in An Giang Province, Vietnam

As water scarcity puts over 80% of the world’s population at risk, water quality has become a major environmental topic. In particular, climate change has jeopardised the quality of water within the Vietnamese Mekong Delta (VMD), a key agronomic and aquaculture hub. A modest canal system and small to medium-sized reservoirs in the semi-mountain region of An Giang province contribute to a less abundant water supply and a tendency for water quality reservoirs to deteriorate. The water quality index method and descriptive technique were used in this study. The results show that in the period 2017–2020, some water quality indicators exceeded the permissible limits of the Vietnamese standards for domestic surface water in column B1 (NO3-, Total Coliform, BOD5, COD, N-NH4+) but are consistent, but are allowed for use in irrigation purposes. Findings show that for many years, WQI values in Tinh Bien and Tri Ton districts have diminished because of wastewater pollution. WQI values near the shores of O Tuk Sa Reservoir (Tinh Bien), Lo^˜i đánh máy (Tri Ton), and O Ta Soc Reservoir (Tri Ton) diminished over time. According to the WQI index, the water quality at the reservoir monitoring stations has fluctuated throughout the years, so it is advised that people implement water purification techniques for long-term well-being.

Hydrogeochemical characteristics and multivariate statistical approach for monitoring groundwater quality scenario in the vicinity of industrial area of western Himalaya, India

ABSTRACT In the present investigation, 50 groundwater samples were collected from Udham Singh Nagar District of Kumaun Himalaya in the pre-monsoon season and 15 physicochemical parameters were analysed using standard procedures. Here, we represent the chemistry of major cations and anions to know the overall water quality and hydrogeochemical characteristics controlling the solute acquisition processes and sources of elements in the study area. The analytical results revealed that in the groundwater samples, Ca2+ and Mg2+ were the dominant cations and was the most dominant anion in the study area. In all the groundwater samples, the content of alkaline earth metals (Ca2++ Mg2+) exceeded the mean content of alkalis (Na+ +K+). In 62% of groundwater samples, the value of weak acid () exceeded the content of strong acid (Cl− + ). Piper diagram, molar ratios and statistical techniques indicated that weathering of carbonate and silicate minerals mostly managed the solute acquisition process with very less involvement of human activities. Most of the groundwater samples were found suitable for potable and domestic purposes except for a few locations nearby SIKDKUL or other industries (the eastern and western part of the study area). Correlation analysis revealed the dependency of WQI values on Fe and Mn content.

Surface water quality assessment in the Bach Dang river basin, Vietnam: using water quality index and geographical information system methods

The study evaluates the surface water quality of the Bach Dang river basin. During the rainy season, the temperature, pH, EC, BOD5, COD, coliforms, ammonium and phosphate values were 27 °C–37 °C, 6.6–8.9, 300–2200 μS cm−1, 5–25 mg l−1, 5–26 mg l−1, 0–3000 MPN/100 mL, below 0.01 mg l−1, and 0.02 mg l−1, respective. During the rainy and dry seasons, Zn, Pb, Cr, As, Fe and Mn levels were below drinking water limits. In the rainy season, the water quality index varied from 76 to 91, signifying medium to excellent water quality. The most outstanding water quality sites were the QN12, QN18, and QN22. During the dry season, most areas had moderate to excellent (WQI values between 61 and 93), except for QN01, QN03, QN04, QN05, QN06, QN07, QN11, QN16, QN17, QN19, and QN23, where it dropped to moderate (61–73). The temperatures were greater and higher EC values in the southeast. The DO concentrations were higher in the northwest and southeast in both seasons. The southern and southeastern regions exhibited more excellent COD and BOD5 values than the western, southwest, north, and northeast regions. The ammonium concentrations were higher in the southeast. During the dry season, the phosphate levels exceeded the permissible limit in the west, southeast, east, and northeast. Coliforms were below acceptable in both seasons, with greater levels in the northwest and northeast during the dry season. In addition, the Zn and Pb are favorably associated with the As, Mn, ammonium and phosphate in the rainy season. The COD positively correlated with the coliforms and BOD5. In the dry season, the pH inversely correlated with the Pb and Fe positively. The ammonium correlated negatively with the DO and positively with the phosphates. The pH negatively connected with the alkalinity, while the As positively correlated with the BOD5 and COD.