Contaminated River Water Research Articles

Farmer’s Perception of River Water contamination in India: A Case study of Rohini River in Maharajganj, India

Background: River water is an indispensable natural resource supporting economic and social development. River has largely been exploited for supplying water for human consumption, livestock drinking, irrigation and other purposes. Despite these benefits, in developing countries, rivers are subjected to various anthropogenic and natural sources of pollution. Hence, the present study aimed to capture farmers’ perception of river water contamination and its impact on farm productivity and human health. Methods: A comprehensive field survey was carried out in the villages of Maharajganj district of Eastern Uttar Pradesh, India from 1 September to 30 September 2021. One control village (polluted) and one uncontrolled (non-polluted) village were selected using a multistage sampling technique. In totality, 1 state, 1 district, 1 Tehsil, 1 Development Block, 2 villages and 100 samples were selected. Result: The results from the study show that farmers are well aware of river water contamination. Hence, the present study recommends the following policy measures. First, a necessity for proper policy, training, and more information on health precautions as well as on food safety in using contaminated river water. Second, when formulating relevant measures, differentiated should be taken for different groups of farmers. Lastly farmers with high dependence on cultivated land may need the most attention.

One health approach to toxocariasis in Brazilian indigenous populations, their dogs, and soil contamination.

Although socioeconomic vulnerability and lifestyle factors may contribute to the transmission of Toxocara spp., no study has investigated indigenous populations in Brazil using the One Health approach. Accordingly, this study assessed anti-Toxocara spp. antibodies in Brazilian indigenous people and healthcare professionals by enzyme-linked immunosorbent assay. Presence of Toxocara spp. eggs (feces and hair) in dogs as definitive hosts and in soil samples of the indigenous communities were also recovered and molecularly investigated. Overall, 342/463 (73.9%) indigenous individuals and 46/147 (31.3%) non-indigenous healthcare professionals were seropositive for Toxocara spp. In addition, T. canis eggs were retrieved from 9/194 (4.6%) dog fecal samples and 4/204 (2.0%) dog hair samples, mainly from the Paraná State communities (3/42; 7.1%). Soil contamination was observed only in the Paraná State communities (36/90; 40.0%), with the molecular detection of T. canis. River water consumption was also associated with indigenous seropositivity (Odds ratio, 11.4). Indigenous individuals in Paraná State communities were 2.72-fold more likely to be seropositive than those in São Paulo State, likely due to a lack of sanitary infrastructure. In this scenario, a primarily soil-transmitted disease may also have become waterborne, with embryonated eggs probably spread to water supplies by rain. Full-time healthcare professionals in daily contact with indigenous communities were 9.2-fold more likely to be seropositive than professionals who visited sporadically, suggesting exposure to Toxocara spp. during their work and raising health concerns. In addition, the findings herein showed a significantly higher seroprevalence in indigenous people than in healthcare workers (χ2 = 85.5; p < 0.0001), likely due to overtime exposure to Toxocara spp. In conclusion, Brazilian indigenous communities are highly exposed to toxocariasis, with poor infrastructure and contact with contaminated river water as associated risk factors and a higher risk of infection in healthcare professionals working full-time in these communities.

Evaluation of ceramic passive samplers using a mixed-mode strong cation-exchange sorbent to monitor polar contaminants in river water

Although most of the analytical methods developed for the monitoring of contaminants in environmental waters are based on discrete grab sampling, an alternative of increasing interest is the use of passive sampling. Methods based on passive sampling provide the sampling and pre-concentration of the analytes in-situ, which makes the sample treatment less time consuming and costly than using discrete grab sampling. In this study, ceramic passive samplers (CPSs) using mixed-mode strong cation-exchange sorbent (Oasis MCX) as retention phase were evaluated for the determination of a group of 21 therapeutic and illicit drugs and some of their metabolites in river water samples that were determined by liquid chromatography-tandem mass spectrometry. After assessing the stability of the analytes, the CPSs were calibrated for 9 days with bottled water and river water, obtaining, for the 19 stable compounds, sample rates (Rs) ranging between 0.180 and 1.767 mL/day and diffusion coefficients (De) between 2.02E-8 and 2.81E-7 cm2/s. Once calibrated, CPSs were deployed for the determination of contaminants in the Ebre River, with good reproducibility, and some of the analytes were determined, including amongst others, gabapentin at 76 ng/L, caffeine at 203 ng/L or diclofenac amine at 57 ng/L. The passive sampling method herein presented is simple and feasible and allows the time-integrated analysis of pharmaceuticals and drugs at trace levels in river water. This study opens the possibility of using other mixed-mode sorbents or other types of sorbents as retaining phase on CPSs for the determination of very polar contaminants in water.

The urbanization impacts on potentially toxic metals: the distribution, sources and contamination risks in river situated in typical megacity, China

The excessive presence of potentially toxic metals (PTMs) in urban river ecosystem deteriorates water quality and presents high potential health issues on both aquatic and urban residents’ life. River water was thus collected around Beijing and Tianjin megalopolis to evaluate urban water pollution. Inverse distance weighted (IDW) method was adopted to reveal PTMs distributions, principle component analysis (PCA) was applied to identify metal origins, and metal pollution indices were applied to evaluate potential contamination threat. PTMs contents displayed in the sequence of Zn > Ni > V > As > Cu > Sb > Fe > Mn > Cr > Co, and Mn concentrations of the most downstream site (321.12 μg/L) far exceeded standard limitation, indicating intense input of urban pollutants near estuary. The distribution of Ni, Co, Cr, V and Sb exhibited a similar variation trend which decreased in middle reach of the Yongding River. As for the Chaobai River, all PTMs concentration in mainstream generally displayed an emerging trend from upper to lower reach without a specific variation pattern. PCA results indicated that Cr, Ni, V, Sb, Co and As mainly originated from mixing sources directly impacted by industrial (thermal) pollution and natural reactions, whereas sources from cultivation (agriculture) and weathering process were associated with Fe and Zn presence. Mn and Cu were mainly responsible for urban activities. The water quality level of the Yongding-Chaobai River varied between “good” and “undrinkable”, and water quality near the river estuary was much lower than other area. Heavy metal pollution index calculation revealed low risks of metal contamination in river water. The electrochemical remediation is more appropriate for PTMs pollution control in megacity river. These findings support the development of effective assessments and monitoring strategies to control urban river pollution and maintain sustainable environment.

Assessment of Microplastics Contamination in River Water, Bottled Water, Sachet Water and Branded Table Salt Samples in Kaduna Metropolis, Nigeria

Microplastics (MPs) &lt; 5 mm-sized are regarded as global environmental contaminants. This study analyzes MP concentrations in the Kaduna River (raw water), treated water from two conventional water treatment plants, brands of bottled water, and food-grade salts available in Kaduna Metropolis, Nigeria using standard methods. Data obtained show that levels of MPs ranged from 25 to 36 particles L-1 in treated water, and to 153 particles L-1 in raw water. While samples of bottled water contained 1.4 to 3.7 particles L-1 and samples of table salt contained 0.13 to 0.27 particles g-1. Water and salt samples contained five different types of polymers, including polyethylene, polypropylene, polyester, polyvinyl chloride and polyethylene terephthalate. Additionally, MPs were divided into three groups based on their physical characteristics. In both raw and treated water, fragments were clearly more prevalent; in samples of bottled water and table salt, fragments and fibers predominated. Microplastics in bottled water pose a medium pollution risk, according to pollution risk indices. The estimated daily intake was generally minimal, indicating little harm from daily consumption, but it also demonstrates that children have a larger intake of microplastics than adults. Leaching from the packing material was identified as the MPs' primary source. This study fills the knowledge gap in the area of emerging microplastic pollution of water sources, drinking water, and food-grade salt.

A Review Paper on Water Pollution in Rivers of the City

Abstract: The availability and quality of water resources has an impact on the political, social, and economic development of a society. Water is deemed dangerous to human and aquatic life when it is contaminated by unexpected chemicals. This water is referred to as being polluted. Water pollution results from many factors. Natural factors include the biodegradation of plant and animal parts in clear water, siltation caused by riverbank erosion, and others. Water pollution caused by humans includes things like fertilisers, household garbage, and industrial waste. Maharashtra's surface water contamination is at an alarmingly high level. Water is essential for all living things, thus there is no need to elaborate. For physiologic purposes, they either directly or indirectly consume water. If the water being consumed is contaminated, harm will undoubtedly result. The worst aspect is that this spreads via the food chain to other people. As a result, we need to be aware of the harmful effects that contaminated water may have on us. One of the fundamental resources required for humanity to survive on Earth is water. The Ganga, Yamuna, and Sabarmati rivers are revered by the Indian population, while the Mithi River is significant for its biodiversity. It is customary to drink from and bathe in the sacred rivers. However, a number of contaminants, including pesticides, heavy metals, organic waste, chemical waste, and sewage discharge, impair the water quality of these rivers. The water is no longer safe for human consumption, raising the risk of disease outbreak. Due to the direct exposure of people and other life forms to hazardous substances and heavy metals through contaminated river water, there is a danger of developing several fatal diseases. This study's goal is to investigate the sources of water contamination in significant Indian rivers and its potential health risks. Although we cannot completely stop water pollution today, reduction is crucial. It's time we started working on it by taking some action.

Dry-column Vacuum Chromatographic Removal of Hg2+ from Wastewater Based on an Acridino-crown Ether-modified Spherical Silica Gel Adsorbent

Dry-column vacuum chromatographic technique is introduced for remediation of wastewater for the first time. A previously prepared chemically modified silica gel containing covalently immobilized Hg2+-selective acridino-crown ether selector molecules was used as an adsorbent. Removal of Hg2+ from highly contaminated river water was carried out to study practical applicability. Adsorption capacity, preconcentration factor, pH-sensitivity and selectivity in separation were determined. The adsorbent proved to be outstanding in selectivity, only Ag+ and Cu2+ interfered among 29 cations, was inert toward organic contaminants, exhibited regenerability and pH-independency between 3.0 ≤ pH ≤ 7.0. The proposed method showed a moderate efficiency in both adsorption (32 mg Hg2+ / 1 g adsorbent) and preconcentration (preconcentration factor of 100). A maximum 10 L of wastewater / 1 g adsorbent ratio is recommended as an upper limit for applicability. The described method showed a unique robustness and simplicity compared to conventional ion-chromatographic methods and an improved selectivity over physical interaction- or simple functional group-based adsorptions.

Natural deep eutectic solvent based ultrasound assisted liquid-liquid micro-extraction method for methyl violet dye determination in contaminated river water

Simple and green natural deep eutectic solvent (NADES) based ultrasound assisted liquid-liquid micro-extraction (UA-LLME) method was developed for extraction and determination of methyl violet dye in contaminated river water samples using UV/Vis spectrophotometry. Choline chloride - decanoic acid based natural deep eutectic solvent was used for extraction. Important analytical parameters like pH, deep eutectic solvent volume/phase ratio, tetrahydrofuran volume, sonication time, and temperature were optimized. Limit of detection (LOD) and limit of quantification (LOQ) were 2.20 μg/L and 7.34 μg/L respectively. Relative standard deviation was 2.35–3.21%. Linearity of method was investigated in a concentration range 10–400 μg/L. Enrichment factor was calculated as 20. For 20 mL sample, the optimized parameters were as deep eutectic solvent volume 1.5 mL, tetrahydrofuran volume was 0.6 mL, pH = 6, sonication time 2 min. The optimized method was tested for extraction of methyl violet in real water samples confirming its applicability in routine environmental analysis.

Status of groundwater and river water quality around the location of illegal gold mining activities in Lantung District, Sumbawa

The Lantung area is one of the places on Sumbawa Island with a large gold deposit. One of the activities of the Lantung people that has the potential to damage the environment is separating gold from mercury. This study aimed to examine the activity of the gold laundering process, and the level of contamination of groundwater and river water due to gold processing from amalgamation by mercury (Hg&lt;sup&gt;+&lt;/sup&gt;) waste. In this study, sampling was carried out for each location, namely two samples of wastewater, six samples of river water, and two samples of groundwater, which were then tested in the laboratory on the parameters of mercury and TSS. At the same time, pH was measured in the field. Furthermore, from the survey results, it was found that the use of mercury was ±150-250 mL at each gold processing location. The results showed that all samples from wastewater (tailings), groundwater and river water were contaminated with mercury with levels exceeding the acceptable quality standards. Furthermore, the status of water quality using the Pollution Index (IP) method shows that wastewater is light to moderately polluted, groundwater is lightly polluted, and river water is also lightly to moderately polluted.

Study of some Physicochemical Characteristics of Polluting River Water in the Cities of Kufa and Hilla

Pollution from industrial, household, and agricultural activity places significant strain on the world’s water supplies. Waste water has a direct influence on the environment since it is released directly into nature after being treated according to particular regulations, and so contains a wide range of bacteria and organic and inorganic substances that cause a variety of diseases and dangers. In this context, water samples from the Euphrates River were obtained in the cities of Al-Hilla and Kufa. These samples were submitted to a series of physicochemical and microbiological analyses, and the findings were compared between the two sites. Physicochemical tests revealed severe contamination of river water collected and evaluated from the two cities, demonstrating the presence of pollutants: (DO) and biological oxygen demand (BOD5). And (TSS), nitrate (NO3), phosphate (PO4), and others. On the other hand, the bacterial isolation and identification approach enabled a direct evaluation of the bacterial diversity present in this waste water, and these analyses demonstrated the severity of the bacterial diversity in these waters.

Geogenic and anthropogenic contamination in river water and groundwater of the lower Cauvery Basin, India

Degradation of water quality is a major challenge in both developed and developing countries since it poses a great risk to ecological health. The Cauvery river is one of the most important rivers of southern India, where the effect of seasonal variation on the quality of river water and its adjoining groundwater on the lower part of the basin has not yet been studied. Hence, the present study was carried out to evaluate the river water and adjacent groundwater for drinking and irrigational purposes, and also to identify the sources affecting the water quality. About 118 river water and 131 groundwater samples were collected over 4 months from May 2018 to August 2019. The water samples were analyzed for electrical conductivity (EC), pH, major and minor ions, and trace elements. The major, minor, and trace elements were then compared with the Bureau of Indian Standards and World Health Organization for drinking water quality assessment. The drinking water quality was assessed, indicating that both river water and groundwater were unsuitable in the coastal regions, especially during dry seasons. Irrigation water quality was also assessed, which indicates that most of the river water and groundwater samples were unsuitable near the coastal region. The quality of river water and groundwater in the lower Cauvery Basin was found to be better during wet periods compared to the dry season. It was observed that the rock–water interactions was the major factor controlling the water quality for groundwater and surface water, followed by anthropogenic activities such as disposal of domestic sewage and effluents into the river, as runoff from irrigated lands. The study emphasizes the development of a finer observational network for water quality, along with stringent monitoring of the disposal of contaminants in the rivers and groundwater.

Mapping the Spread of Mercury from Artisanal Mining Activities in Aceh Jaya through Geochemical Surveys

Illegal gold mining carried out using amalgamation techniques produce mercury waste which can then damage the environment and damage the health of residents. The negative impact due to the use of mercury is dead fish, contaminated river water, water quality below environmental standard quality and spreading in the food chain. This has caused environmental damage, one of which is in terms of land and water. This condition is the basis for conducting deeper research on environmental damage by mercury waste, especially in terms of soil and water. The sampling method used is the Geochemical Method and Geoelectric Method. Geoelectric samples were taken using the superstring R8 tool. Geochemical samples used were soil and water samples which were subsequently tested by the Atomic Absorption Spectrophotometry (AAS) and X-ray Fluorescence (XRF) methods to see the mercury levels that had been scattered in the research location. The study aims to determine the distribution of mercury waste and its levels. This research includes sampling, sample testing, data processing and analysis, and making maps of the distribution of mercury waste through QGis software. From the study, it was found that the distance from the traditional gold mining processing location determines the concentration level (Hg). Analysis using AAS shows that there were 13 samples had mercury concentrations above the critical threshold. From the analysis, it is also known that AAS could not detect mercury levels in soil samples which is different from the results obtained using XRF.

Impact of Mining and Ore Processing on Soil, Drainage and Vegetation in the Zambian Copperbelt Mining Districts: A Review

The regional environmental–geochemical surveying of the long-term impacts of mining and ore processing on a large part of the Zambian Copperbelt mining district was carried out by the Czech Research Group with cooperation of the Geology Department, University of Zambia, and the Geological Survey of Zambia in the period 2002–2018. This included the characterization of various sources of contamination, the extent of contamination of soils and crops, and the degree of contamination of river water and sediments. Solid speciation studies of potentially harmful chemical elements (PHEs), plant and human bioaccessibility studies, and a range of mineralogical techniques were used to assess the pathways of PHE cycling in terrestrial and aqueous systems and their impacts on human health. Ores of the Zambian Copperbelt mining district are mined for Cu and Co, but a number of other trace elements (Pb, As, Cd, Hg, Pb, Zn) gradually accumulated in soils and stream sediments. It was concluded that the most important problems related to ore mining and processing are the contamination of soil and crops due to dust fall out from tailing facilities and emissions from smelters. Moreover, leakages of solutions from tailing dams, insufficient technological control of their stability and breakdowns on pipelines transporting slurry from treatment plants to tailing impoundments cause contamination of water courses and deposition of metal(loids) in stream sediments. However, the contamination of the Kafue River water is relatively limited due to its high neutralization capacity. In contrast, in some Kafue River tributaries, especially those close to big mining centers, the concentrations of dissolved Cu and Co are high (up to 14,752 μg/L and 1917 μg/L) and exceed Zambian effluent limits. We also recommend measures that could contribute to minimizing the impact of ore mining and processing on the environment and the health of the local population.

The significance of applying different factors for the evaluation of sediment contamination by toxic elements and estimation of the ecological risk.

The optimized three-step sequential extraction procedure for the fractionation of micro- and macroelements, was conducted to determine fractional characteristics of PTEs (potentially toxic elements) in surface sediments of rivers in the Vlasina watershed. The sequential extraction results, which enable the evaluation of mobility of the studied elements, have indicated that Zn, Ni, Cu, Cr, and As can be considered slightly mobile, whereas Pb, Mn, Cd, and Co were regarded as possibly mobile elements. Lead was dominantly bounded (specifically adsorbed or co-precipitated) to iron and manganese oxides (up to 80%) and may be released by reduction. Since the content of the exchangeable fraction (F1) is an indicator for anthropogenic impact on the aquatic environment, a low percentage (0-8%) of studied toxic elements in this fraction indicated that these elements have lithogenic origin in most sampling locations in the area of study. Except for Pb, the substantial positive correlations between Al and other elements showed that studied elements came primarily from terrigenous sources. Although the values obtained for the risk assessment code (RAC) indicated a slightly increased mobility of some elements (up to 22.44%), the values of the modified risk assessment code (mRAC), which include toxic effects on the environment, showed there is no danger of pollution by studied elements (all values were < 1%). Our recommendation is to use mRAC instead of RAC in ecochemical studies and assessment of the degree of sediment and soil pollution, because mRAC includes toxic effects of elements. Based on ATI values, river sediments show no toxic to a low toxic degree. Even though obtained results indicate that there was no considerable risk for river water contamination, the ecological risk for Fe and Pb should be monitored in the future.

CrAssphage May Be Viable Markers of Contamination in Pristine and Contaminated River Water.

Viruses are the most biologically abundant entities and may be ideal indicators of fecal pollutants in water. Anthropogenic activities have triggered drastic ecosystem changes in rivers, leading to substantial shifts in chemical and biological attributes. Here, we evaluate the viability of using the presence of crAssphage as indicators of fecal contamination in South African rivers. Shotgun analysis revealed diverse crAssphage viruses in these rivers, which are impacted by chemical and biological pollution. Overall, the diversity and relative abundances of these viruses was higher in contaminated sites compared to pristine locations. In contrast to fecal coliform counts, crAssphage sequences were detected in pristine rivers, supporting the assertion that the afore mentioned marker may be a more accurate indicator of fecal contamination. Our data demonstrate the presence of diverse putative hosts which includes members of the phyla Bacteroidota, Pseudomonadota, Verrucomicrobiota, and Bacillota. Phylogenetic analysis revealed novel subfamilies, suggesting that rivers potentially harbor distinct and uncharacterized clades of crAssphage. These data provide the first insights regarding the diversity, distribution, and functional roles of crAssphage in rivers. Taken together, the results support the potential application of crAssphage as viable markers for water quality monitoring. IMPORTANCE Rivers support substantial populations and provide important ecosystem services. Despite the application of fecal coliform tests and other markers, we lack rapid and reproducible approaches for determining fecal contamination in rivers. Waterborne viral outbreaks have been reported even after fecal indicator bacteria (FIB) were suggested to be absent or below regulated levels of coliforms. This indicates a need to develop and apply improved indicators of pollutants in aquatic ecosystems. Here, we evaluate the viability of crAssphage as indicators of fecal contamination in two South African rivers. We assess the abundance, distribution, and diversity of these viruses in sites that had been predicted pristine or contaminated by FIB analysis. We show that crAssphage are ideal and sensitive markers for fecal contamination and describe novel clades of crAss-like phages. Known crAss-like subfamilies were unrepresented in our data, suggesting that the diversity of these viruses may reflect geographic locality and dependence.

Cholera outbreak associated with drinking contaminated river water in Panyimur and Parombo sub-counties: Nebbi district, Uganda, March 2017

Introduction: On 10thFebruary 2017, Uganda Ministry of Health was notified of a suspected cholera outbreak in Nebbi district. The district experienced numerous cholera outbreaks with the latest in 2016. We investigated to determine the scope, mode of transmission, and exposures. Methods: We defined a suspected case as sudden onset of acute watery diarrhoea in a resident (&gt;5 years) from Parombo or Panyimur subcounties in Nebbi district, during 1 January-9 March 2017. A confirmed case was a suspected case with culture-confirmed Vibrio cholerae from stool. We conducted descriptive epidemiology of case-persons to inform hypothesis generation and a case-control study involving 67 case-persons and 134 control-persons to test the hypothesis. Results: We identified 222 suspected case-persons; samples from two yielded Vibrio cholerae O139. Three case-persons died (CFR=1.4%). The epidemic curve indicated a point-source outbreak. Among 67 cases, 40 (60%) drank river water, compared with 56 (42%) of 134 controls (OR 2.2, 95% CI: 1.2- 4.1). Visual assessment revealed that river water had high turbidity and we observed mass open defecation. Conclusion: This outbreak affected two sub-counties and was associated with drinking contaminated river water. We recommended treating drinking water by the community members and health education on drinking water safety and proper waste disposal in the communities. And for long term, the district water department should increase the number and functionality of boreholes or piped water in the communities.

Environmental risk assessment of the contamination of river water and sediments from the Bor mining area, East Serbia―Secondary Cu enrichment at the reservoir site

AbstractThe study area is within the Bor copper mining region, Eastern Serbia, where wastewaters from the Bor metallurgical/smelting facilities have caused serious copper (Cu) and arsenic (As) contamination to the Timok river system. The operating conditions at smelting facilities control the pH of the river waters, resulting in highly acidic waters in 2019 than 2015. This study compares the mobility of Cu and As and risk assessment of river water contamination during both years as well as assessing the risks of riverbed sediments contamination and investigating the origins of Cu and As pollution. In the river system, As generally existed as a particulate species in the entire study area during both years and was widely removed from river waters by sorption onto the hydrous ferric oxides (HFO), whereas dissolved Cu was removed from river waters only at neutral pH conditions with hydrous aluminum oxides (HAO) and HFO at the downstream reservoir site of Timok River. Despite the similarity in Cu mobility during both years, the lower pH of river waters in 2019 than 2015 enabled dissolved Cu species to be transported farther downstream, resulting in a higher level of river water pollution. The contamination factor (CF), used to estimate levels of sediment pollution, had higher values for Cu and As compared to Zn, Pb, Co, and Ni. The CF values of Cu were the highest in sediments near the Bor metallurgical/smelting facilities and at downstream reservoir site, whereas the CF values of As were generally high in the entire research field. Additionally, the ecological risk potential (Er) values of Cu were the highest in sediments of the Bor River and Timok River, reflecting an enrichment of Cu at these sites. Finally, a clarification on the origin of Cu pollution and risks of mobilization was inferred from the sequential extraction test. The predominant Cu species in sediments of the upstream region were oxidizable and residual, hosted by copper sulfides originating from the flotation tailings, suggesting a relatively low risk of Cu release from these sediments. However, at the downstream site (especially reservoir sediments), the contribution of acid‐soluble Cu was 34.8%, suggesting a higher risk of Cu release. The highest contributions of acid‐soluble and reducible Cu (18%) at the reservoir site were promoted by the effective settlement of Cu‐sorbing HAO and HFO. The Cu contents of these two fractions were 0.86 wt%, almost three times higher than that of Cu ore in Veliki Krivelj open pit mine.

Screening and characterization of bacterial isolates for degradation of recalcitrant pollutants from River water

The restoration of river ecosystems depends on the utilization of the most effective river water treatment techniques. Yamuna river water of Agra city is heavily contaminated with toxic pollutants including heavy metals and pesticides that causes severe damage to ecological and social aspects. At present, the direct use of river water for the purpose of drinking causes severe hazards due to anthropogenic activities causing environmental pollution in rivers. The four bacterial isolates (Rhodopseudomonas palustris Bacillus subtilis, Bacillus fusiformis, and Rhodobacter sphaeroides) were used in the form of monocultures and consortium for the bioremediation purposes. According to the results obtained, a significant reduction were observed in the physico chemical parameters including heavy metals. Hence, bioremediation is considered to be an attractive option for minimizing the pollution load from contaminated river water due to its high efficiency and economical impact than chemical remediation. Thus the current study clearly states that, application of bacterial consortia and monocultures can be used for the treatment of toxic effluents from Yamuna river water.

Major ion hydrogeochemistry and health risk of groundwater nitrate in selected rural areas of the Guanzhong Basin, China

In this study, the hydrochemical characteristics of groundwater were assessed based on 64 shallow groundwater samples collected in the Guanzhong Basin, China, and the health risk of nitrate (NO3 -) in drinking water was assessed. In addition, the spatial distributions of major water quality indicators were investigated, while bivariate plots, saturation index, and stable isotopes were used to reveal the processes controlling groundwater hydrogeochemistry. The results showed that groundwater in the study area was mostly fresh water. However, the maximum and average NO3 – concentrations were 397.0 and 92.9 mg/L, respectively, indicating serious groundwater NO3 – pollution. The percolation of contaminated river water exhibited considerable impacts on groundwater quality. Carbonate dissolution was the major process controlling the hydrochemical characteristics of groundwater, while human activities were responsible for the high concentrations of groundwater pollutants, especially NO3 –. Evaporation fraction of groundwater in the study area revealed by stable hydrogen and oxygen isotopes ranged from 4 to 13% and 4 to 11%, respectively. High non-carcinogenic health risks of NO3 – to adults and children were observed in about 46.88 and 75% of the collected groundwater samples, respectively. The risk value ranges were 0-6.00 and 0-14.06, with average values of 1.36 and 3.19, for adults and children, respectively.

Distribution of Cr, Cd, Cu, Pb and Zn in organs of three selected local fish species of Turag river, Bangladesh and impact assessment on human health

The current study estimates the contamination status of heavy metals in fish organs of three local fish species including Amblypharyngodon microlepis (Mola), Trichogaster chuna (Chuna Khalisha) and Annaldale Loach (Gutum fish) which were collected from Turag river during the months from January to March 2022. The heavy metal concentrations of river water and fish organs were assessed through Atomic Absorption Spectrophotometer (AAS). Heavy metals in river water was detected in the order of Ni > Zn > Cu > Cd > Pb > Cr while metal accumulation in the fish organs were detected in the order of Zn > Cr > Cu > Pb > Cd, Zn > Cu > Cr > Pb > Cd and Zn > Cu > Cr > Pb > Cd for Trichogaster chuna, Amblypharyngodon microlepis and Annaldale Loach respectively. Among the detected heavy metals, highest contamination factor (CF) of Zn (1.104198) in intestine and lowest CF of Cu (0.00315) was detected in muscle of Amblypharyngodon microlepis (Mola). On the other hand, highest CF of Cd (1.072772) in liver and lowest CF of Zn (0.0225016) in gill of Trichogaster chuna (Chuna Khalisha) was detected. In case of Annaldale Loach (Gutum fish), highest CF of Cu (0.304122) in liver and lowest CF of Zn (0.002593) in intestine was detected. The total target hazard quotients (TTHQ) values of Amblypharyngodon microlepis in liver (1.18816) exceeded allowable threshold of 1 while TTHQ values in the muscle (1.8862) and liver (1.03995) of Annaldale Loach (Gutum fish) surpassed the acceptable standard limit as well. The TTHQ values (Gill- 0.18764, Muscle- 2.1633, Intestine- 1.68741, liver- 1.03995, kidney- 1.82188) for all of the organs of Trichogaster chuna (Chuna Khalisha) exceeded the acceptable standard limit which indicated possible non-cancer risk for all consumers and some of the fishes found unsafe if they are consumed for a longer time. However, the target cancer risk (TCR) values indicated no potential cancer risks by consumption of those fishes. The regulatory authorities should pay more attention to reduce the river water contamination through industrial effluents which might affect public health.