This study was undertaken to evaluate concentration of Uranium (U) in the drinking water of the Tonk district of Rajasthan (India). The main objective of the study is to determine the distribution of Uranium concentration and the geochemical behavior of Uranium in pre-monsoon (PRM) and post-monsoon (POM) drinking water samples. Uranium was measured by LED fluorimeter. Total 318 drinking water samples were collected for both seasons. It is observed that the water quality of all the samples is within the limits prescribed by WHO (30 µg/L) except a few, and can be used for domestic purposes. The Uranium concentration was found to be in the range 0.21 to 173.72 µg/L with a mean value of 8.58 µg/L in pre-monsoon and 0.21 to 162.34 µg/L with a mean value of 11.22 µg/L in post-monsoon samples. The geochemistry of the study area shows rock-water interaction. The order of average anionic concentration is found to be HCO3 – > Cl – > SO4 2– > NO3 –. Although no definite trend of seasonal variation in the concentration of U was observed, large samples have higher Uranium concentrations in post-monsoon than pre-monsoon.

Migratory fish populations have experienced great declines, and considerable effort have been put into reducing stressors, such as chemical pollution and physical barriers. However, the importance of natural sounds as an information source and potential problems caused by noise pollution remain largely unexplored. The spatial distribution of sound sources and variation in propagation characteristics could provide migratory fish with acoustic cues about habitat suitability, predator presence, food availability and conspecific presence. We here investigated the relationship between natural soundscapes and local river conditions and we explored the presence of human-related sounds in these natural soundscapes. We found that 1a) natural river sound profiles vary with river scale and cross-sectional position, and that 1b) depth, width, water velocity, and distance from shore were all significant factors in explaining local soundscape variation. We also found 2a) audible human activities in almost all our underwater recordings and urban and suburban river parts had elevated sound levels relative to rural river parts. Furthermore, 2b) daytime levels were louder than night time sound levels, and bridges and nearby road traffic were much more prominent with diurnal and weekly patterns of anthropogenic noise in the river systems. We believe our data show high potential for natural soundscapes of low-land river habitat to serve as important environmental cues to migratory fish. However, anthropogenic noise may be particularly problematic due to the omnipresence, and relatively loud levels relative to the modest dynamic range of the natural sound sources, in these slow-flowing freshwater systems.

Macrolitter, especially macroplastics, (> 0.5 cm) negatively impact freshwater ecosystems, where they can be retained along lake shores, riverbanks, floodplains or bed sediments. Long-term and large-scale assessments of macrolitter on riverbanks and lake shores provide an understanding of litter abundance, composition, and origin in freshwater systems. Combining macrolitter quantification with hydrometeorological variables allows further study of leakage, transport, and accumulation characteristics. Several studies have explored the role of hydrometeorological factors in influencing macrolitter distribution and found that river discharge, runoff, and wind only partially explains its distribution. Other factors, such as land-use features, have not yet been thoroughly investigated. In this study, we provide a country-scale assessment of land-use influence on macrolitter abundance in freshwater systems. We analyzed the composition of the most commonly found macrolitter items (referred to as ‘top items’, n = 42,565) sampled across lake shores and riverbanks in Switzerland between April 2020 and May 2021. We explored the relationship between eleven land-use features and macrolitter abundance at survey locations (n = 143). The land-use features included buildings, city centers, public infrastructure, recreational areas, forests, marshlands, vineyards, orchards, other land, and rivers and canals. The majority of top items are significantly and positively correlated with land-use features related to urban coverage, notably roads and buildings. Over 60% of top items were found to be correlated with either roads or buildings. Notably, tobacco, food and beverage-related products, as well as packaging and sanitary products, showed strong associations with these urban land-use features. Other types of items, however, did not exhibit a relationship with land-use features, such as industry and construction-related items. Ultimately, this highlights the need to combine measures at the local and regional/national scales for effective litter reduction.

Plastic pollution is ubiquitous in aquatic environments worldwide. Rivers connect terrestrial and marine ecosystems, playing a key role in the transport of land-based plastic waste towards the sea. Emerging research suggests that in estuaries and tidal rivers, tidal dynamics play a significant role in plastic transport and retention dynamics. To date, observations in these systems have been limited, and plastic transport dynamics during single tidal cycles remain poorly understood. Here, we investigated plastic transport, trapping, and re-mobilization of macroplastics (> 0.5 cm) in the Saigon River, focusing on short-term dynamics of individual tidal cycles. We used GPS trackers, released at different stages of the tidal cycle (ebb, flood, neap, spring). Plastic items demonstrated dynamic and intermittent transport behavior. Items spent almost half of the time (49%) temporarily stopped, mainly due to their entrapment in vegetation, infrastructure, or deposition on riverbanks. Items were almost always re-mobilized within 10 h (85%), leading to successive phases of stopping and transport. Tidal dynamics also resulted in bidirectional transport of plastic items, with median daily total transport distance within the 40 km study reach (8.9 km day−1) over four times larger than the median daily net distance (2.0 km day−1). The median retention time of plastic items within the reach was 21 days (mean = 202 days). In total, 81% of the retrieved items were trapped within water hyacinths, emphasizing the important role of floating vegetation on river plastic transport dynamics. With this paper, we aim to provide data-driven insights into macroplastic transport and retention dynamics in a tropical tidal river. These are crucial in the design of effective intervention and monitoring strategies, and estimating net plastic emission from rivers into the sea.

This study meticulously explores the intricate hepatotoxic effects stemming from acute exposure to gaseous sulfur dioxide (SO2), nitrogen dioxide (NO2), and their amalgamation on sea bass (Centropristis striata). Employing a comprehensive approach involving hematological, cytotoxic, and histochemical analyses, the research provides crucial insights into the potential adverse impacts of these pollutants on fish health. The examination specifically focuses on the effects of SO2+NO2 on hematological, histochemical, and serum biochemical parameters in Centropristis striata. Treatment groups, subjected to LC30, LC50, and LC90 acute exposure of gaseous SO2, NO2, and SO2+NO2, alongside a control group, underwent evaluation of parameters such as red and white blood cells, hemoglobin, hematocrit, mean corpuscular hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin concentration, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, acid phosphatase, lactate dehydrogenase, total protein, albumin, serum creatinine, and blood urea. At the 96th hour, RBC values decreased, and WBC values increased in all experimental conditions compared to the control group (p>0.05). MCV and MCH increased with the concentration of gaseous pollutants and exposure time (p>0.05). Hematological parameter variations underscore disruptions in blood composition and immune responses. Simultaneously, alterations in serum biochemical parameters suggest potential impairments in liver and kidney functions, along with disturbances in lipid metabolism. Significant declines in albumin levels, indicating potential liver dysfunction or inflammation due to SO2 and NO2 exposures, were observed at all experimental conditions, while decreased globulin levels suggest immunosuppressive effects from combined pollutants. A substantial increase in the albumin/globulin ratio further signals an imbalance indicative of potential liver dysfunction or inflammation. Varied responses in liver enzyme levels (SGPT/ALT, SGOT/AST, ALP) underscore potential liver damage or injury (p< 0.05). These findings deepen our understanding of environmental impacts on aquatic ecosystems, emphasizing the need for ongoing efforts to ensure the health and sustainability of fish populations in polluted environments.

A study on the biodiversity and isolation of freshwater algae from some reservoirs of Mae Rim Campus, Chiang Mai Rajabhat University, Chiang Mai Province, collected algal samples and assessed the water quality at four reservoirs, including Wiang Bua Reservoir, Ma Lang Por Reservoir, Education Auditorium reservoir, and Kru Noi Garden Reservoir. One hundred and six species of algae belonging to 8 phyla were found. The most prominent species were Cylindrospermopsis philippinensis, Trachelomonas volvocina, Peridiniopsis sp., and Coelastrum astroideum, respectively. The overall water quality was categorized as clean according to some physical and chemical parameters by the National Environmental Board of Thailand. However, high BOD values were detected at some sampling points. The algae isolation included 8 isolates, which could be utilized for various purposes in the future, such as biomass, protein, polysaccharide energy, bioactive compounds, antioxidant substances, wastewater treatment, environmental indicators, algal toxins, and phylogenetic studies. All strains were stored at the Centre of Excellence of Biodiversity Research and Implementation for Community, Chiang Mai Rajabhat University, for conservation and future development purposes.

The stated goal of the research is to investigate the surface water quality of the Baitarani River in Odisha to ascertain its compatibility for various uses. Large, complex datasets generated during the one-year (2021-2022) monitoring program were collected from 13 locations and encompassed 22 parameters. To examine temporal and spatial fluctuations in and to interpret these datasets, MCDMs like TOPSIS and the Entropy-based Water Quality Index (EWQI) were utilized. The physical and chemical outcomes of the current experiment were compared to WHO standards. According to the analysis’s results, turbidity and total coliform (TC) are indicators that have a greater impact on water quality in all locations during both seasons and are directly linked to home and agricultural non-point source pollution. As per EWQI interpretation, 30.77 % of the observations in PRM and POM fall under the poor category. The findings showed how anthropogenic activities have harmed St. 8, 11, 12, and 13 and require effective management. A quantifiable approach was also carried out to decide the efficacy of TOPSIS. Farming attributes, including SAR, % Na, RSC, MR, KI, and PI, were estimated to delineate the agriculturally practicable zones. This work can offer a reference database for the betterment of water quality.

Monitoring water quality changes in any body of water is crucial as it directly relates to climate change. Evaluating the quality and quantity of fresh water for various uses is essential to maintaining safe water sources now and in the future. This study examined the water quality of the Main Outfall Drain River (MOD) in the eastern part of Al-Qadisiya Governorate at three sites over four seasons in 2023, using the Iraqi Water Quality Index (IQ-WQI). In most cases, the concentrations of dissolved oxygen (DO), biochemical oxygen demand (BOD5), and total dissolved solids (TDS) exceeded allowable limits for freshwater and aquatic life protection. The major contributing parameters to the river’s low water quality were TDS, BOD5, turbidity, and DO. The use of the MOD for discharging agricultural effluents led to increased levels of TDS, BOD5, and turbidity. Temporal variation indicated that the summer season had the highest values compared to other seasons due to increased evaporation and low water discharge. Spatial variation showed the IQ-WQI of the sites in descending order from very poor water to unsuitable, with Site 3 having double the TDS concentrations compared to other sites. This increase may be attributed to the impact of the Al-Dalmag Marsh discharge canal, which comes into contact with the MOD at this site. Sensitivity analysis using backward linear regression was applied to predict the IQ-WQI and determine the most influential parameters on the IQ-WQI score. The test was conducted for two sets of water parameters (from the IQ-WQI calculation) and included 7 parameters for each freshwater and aquatic life use, obtaining different models.

The quantity of contaminants being released into rivers is rising in direct correlation with the growth of the human population. Bedog River is a tributary located in the vicinity of Mount Merapi. This river flows through agricultural, residential, and cattle sectors, making it easier to detect river contamination. The objective of this study is to evaluate the water quality of the Bedog River. The research employs a methodology that evaluates water quality by considering biological indicators, specifically the existence of dragonfly species, with the analysis of other chemical and physical properties in river water. The water quality research findings indicate that the physical and chemical characteristics remain satisfactory, with the water falling into the moderately polluted category. It also meets the water quality criteria outlined in PPRI No. 82 of 2001, specifically the class 2 threshold. A total of 23 Odonata species were identified. The upstream section, as indicated by the presence of Neurobasis chinensis florida and Heliocypha fenestrata, which are endemic, along with Macrogomphus parallelogramma, which is rare, is considered an optimal habitat capable of supporting sensitive dragonfly species. The dragonfly variety index in the Bedog River is relatively high, with values of 2.08, 2.79, and 1.47 for the upstream, middle, and downstream sections, respectively. The Pearson correlation coefficient indicates a strong positive correlation of 0.961, while the significance level of 0.179 suggests a statistically meaningful association. The findings highlight the potential of using dragonflies as bioindicators for long-term monitoring of river health and pollution levels. This study contributes to the understanding of how water quality impacts biodiversity and provides a basis for future research and river management practices. This research fills a gap by integrating biological indicators with traditional water quality assessments in a specific regional context. It provides new insights into the relationship between water quality and dragonfly diversity, offering valuable information for environmental monitoring and conservation efforts.

Aquatic ecosystems that are subject to urbanization and environmental changes, such as the Kapaleeswarar and Chitrakulam tanks, depend on evaluating water quality. Their complicated data present challenges for conventional approaches. The usefulness of the Mamdani fuzzy inference system in determining the water quality in these tanks is investigated in this work. It creates a comprehensive assessment based on subject-matter expertise by handling ambiguous descriptors with linguistic variables and fuzzy sets. The system’s procedures for implementation are described in detail, with an emphasis on how well they can manage interrelated variables. The study shows how well the system measures the water quality in tanks and suggests ways to improve it. Tank evaluation that incorporates the Mamdani system encourages comprehensive resource management and cultural preservation.