Lake Pollution Research Articles

Impact of Land Use Change on Lake Pollution Dynamics: A Case Study of Sapanca Lake, Turkey

Modeling non-point source pollution dynamics in inland lake basins is essential for safeguarding water quality, maintaining ecosystem integrity, protecting public health, and advancing long-term environmental sustainability. This study explores non-point pollution dynamics in the Sapanca Lake basin, Turkey, in association with the basin’s land use, land cover, hydrology, pollutant sources, and water quality parameters. The required data were gathered via a three-year monitoring program, which was carried out at 12 sampling stations around the lake, as well as using the collecting field measurements and GIS databases. Stepwise multiple regression analysis was employed to determine the best relation between non-point pollutants and land features. The results showed that urbanization and population density have significant correlations with the total nitrogen (TN) and total phosphorus (TP) in the study areas. Rivers crossing pristine areas, such as forests and uncultivated lands, demonstrated better water quality, thereby positively contributing to the lake ecosystem conservation. The highest nutrient loads were observed in streams that flow through highly urbanized sub-basins, followed by predominantly agricultural areas. This is likely due to runoff from urban environments, leaching from cultivated land, and contributions from livestock and tourism facilities. Conversely, densely forested regions exhibited the lowest levels of nutrient loads, highlighting their capacity for nutrient retention. The peak levels of non-point source pollution (TN = 5.22 mg/L and TP = 0.53 mg/L) were recorded in catchments with the highest degree of urbanization, whereas the lowest values (TN = 0.28 mg/L and TP = 0.04 mg/L) were found in the least urbanized areas. These findings emphasize that nutrients primarily impact water quality because of increasing urban and agricultural activities, while forested land plays a vital role in preserving lake water quality. To ensure sustainable water quality in lake basins, it is essential to strike a careful balance between protective measures and utilization policies, prioritizing conservation efforts.

Оценка туристско-рекреационного потенциала озер города Краснодара

The article presents the results of research on the tourist and recreational potential of water bodies within the boundaries of the municipality of Krasnodar, conducted using the author's methodology based on previously developed methodological approaches. The assessment of the degree of suitability of the use of the city's water bodies for tourism and recreation purposes was carried out according to a set of parameters: water quality according to the main hydrochemical indicators, the degree of attractiveness and uniqueness of landscapes, the development of tourist infrastructure, the intensity of use in tourist and recreational activities, taking into account the principles of rational recreational nature management, etc.; and the limiting factors of the development of the tourist and recreational sphere are also identified (for example, pollution of reservoirs). According to the developed assessment scale, the most promising water bodies for organizing recreation for the population have been identified – Lakes Staraya Kuban and Verkhneye Pokrovskoye. In conclusion, measures are proposed aimed at increasing the tourist attractiveness of all the studied reservoirs, the main of which are aimed at eliminating sources of lake pollution, landscaping the coastal zone, expanding the types of their tourist and recreational use, monitoring the wastewater treatment system, etc.; The necessity of creating a cadastre of tourist resources was also determined, due to the importance of providing executive authorities, local governments and tourist organizations with up-to-date information about the tourist potential of a particular territory.

Eutrophication exacerbated organic pollution in lakes across China during the 1980s-2010s

Lakes are vital sources of drinking water and essential habitats for humans and various other living organisms. However, many lakes face organic pollution due to anthropogenic disturbance and climatic influence, and the spatiotemporal changes of organic pollution in lakes over a large area are still unclear. Based on three monitoring datasets of chemical oxygen demand (COD) in 390 lakes, this study demonstrated the apparent spatiotemporal differences of organic pollution in lakes during the 1980s-2010s and the effects of water eutrophication and salinization. Throughout China, lake organic pollution showed a general spatial trend of being more severe in the north compared to the south. This pattern is reflected in the positive linear correlations between in-situ COD concentrations and lake latitude, observed in both the 1980s (p < 0.05) and the 2010s (p < 0.01). In terms of spatial differences, the influence of total nitrogen concentrations increased from 0.27% in the 1980s to 35.24% in the 2010s. Moreover, with increasing human activity, 78.31% of the studied lakes (N = 83) showed increasing COD concentrations during the 1980s-2010s. In addition, the logarithmic dissolved organic carbon concentrations were linearly correlated with log water conductivities (Pearson's r = 0.49, p < 0.01), suggesting that lake expansion would attenuate organic pollution in saline lakes through dilution effects. These results are valuable for understanding the spatiotemporal dynamics of organic pollution and are crucial for effective management of organic pollution in different lakes.

Numerical Simulation of Lake Pollution Model via Crank-Nicolson Finite Difference Scheme

Lake pollution has become a serious challenge considering the number of infectious diseases caused by contaminated water. To understand more about the concentration of pollutant released in a lake, this study formulates a partial differential equation (PDE) model of parabolic type, discretized via the Crank-Nicolson scheme. The accuracy of the formulated scheme was ascertained through the Von Neumann analysis. Our numerical simulation reveals that the concentration of pollutants spreads exponentially at each time steps

Spatial Distribution, Source Analysis, and Risk Assessment of Multiple Antibiotics in Chaohu Lake Basin

Chaohu Lake is the fifth largest freshwater lake in China that meets the needs of surrounding industries for water, tourism, and flood storage, making it important for the socio-economic development and modernization of Anhui Province. As an important ecological wetland in the lower reaches of the Yangtze River, many rare bird habitats are present along the coast of Chaohu Lake. Therefore, it is eco-economically important to study antibiotic pollution in Chaohu Lake. To unveil antibiotic contamination in Chaohu Lake, surface water and sediment samples were collected from the main basin of Chaohu Lake by steamship in June 2022. Solid phase extraction and ultra-performance liquid chromatography-mass spectrometry （SPE-UPLC-MS） was used to determine the occurrence of 31 target antibiotics, including tetracyclines, sulfonamides, macrolides, and quinolones. The study focused on the spatial distribution, source analysis, and risk assessment of various antibiotics in the surface water and sediments of the main basin of Chaohu Lake. The occurrences of 20 different antibiotics were successively identified in the surface water and sediments of Chaohu Lake. These antibiotics included sulfonamides, quinolones, macrolides, tetracyclines, and others. Significant spatial differences in antibiotics were found between surface water and sediments. The horizontal spatial distribution results indicated differences in species and concentration of antibiotics in surface water and sediments. The vertical spatial distribution results showed that many types of antibiotics had consistent vertical distribution characteristics in surface water and sediments at the same point. The principal component analysis results indicated that the source of antibiotics in surface water was similar to that in sediment and considered with the actual distribution of existing industries around Chaohu Lake； the main sources were livestock and poultry breeding sewage, aquaculture sewage, and household sewage. The ecological risk quotient （RQ） results indicated that norfloxacin in the surface water of Chaohu Lake posed a high risk to algae （RQ &gt; 1）, while sulfamethoxazole and doxycycline posed a medium risk to algae （0.1 ≤ RQ &lt; 1）. The health risk quotient （HRQ） showed that the risk of exposure to antibiotics through drinking water was very low （HRQ &lt; 0.01）. Our findings provide scientific support for decision makers to control antibiotic pollution and reduce the management costs of antibiotic watershed pollution.

A Preliminary Health Risk Assessment of Heavy Metal Contamination in Chembarambakkam Lake, Tamil Nadu, South India

Chembarambakkam Lake, an important freshwater reservoir in Chennai that provides drinking water to the city, has noticed a decline in water quality as a result of heavy metal pollution. This study aimed to evaluate the heavy metal contamination in the environment of Chembarambakkam Lake with a health risk assessment. This study involved a comprehensive analysis of toxic heavy metal levels in five waters, sediments, and commercially available freshwater fish samples, considering their bioaccumulation and potential risks to human health. We observed lead (Pb), cadmium (Cd), zinc (Zn), and copper (Cu) concentrations in water, sediments, and various fish species, including tilapia (Mozambique Tilapia), wild carp (Hemiculter leucisulus), pearl-spot (Etroplus maculatus), spotted barb (Barbodes binotatus), and snakehead murrel (Channa Striate). The results indicated that, in order of prominence, the metals in the water were Cu &gt; Zn &gt; Pb &gt; Cd, whereas those found in sediments were Zn &gt; Cu &gt; Pb &gt; Cd. The metal concentration in the sediments varied between Cd (0.52–0.82 µg/g), Cu (13.75–38.07 µg/g), Pb (1.30–3.74 µg/g), and Zn (12.60–61.12 µg/g). Similarly, the metal concentrations in the water varied between Cd (0.63–0.72 µg/L), Cu (5.35–55.17 µg/L), Pb (BDL–12.39 µg/L), and Zn (0.62–1.49 µg/L). The order of metals in the fish was Zn &gt; Cd &gt; Cu &gt; Pb. The Cd concentration ranged from 0.3 to 0.60 µg/g, Cu was from BDL to 0.72 µg/g, Pb was from BDL–0.68 µg/g, and Zn was from 13.32–48.48 µg/g. The Cd and Zn concentrations were consistently the highest across the fish, sediment, and water samples. These findings shed light on the health risks associated with heavy metal pollution in Chembarambakkam Lake and suggest the need for potential bioremediation approaches.

Heavy metals in sediments of the river-lake system in the Dianchi basin, China: Their pollution, sources, and risks

The accumulation of heavy metals in river and lake sediments in basins seriously threatens ecological safety and human health. To manage the basin effectively, it is crucial to understand pollution levels and identify and quantify the sources and risks of heavy metals in rivers and lakes separately for targeted control. In this study, 34 sediment samples were collected from the Dianchi Basin, China, and the pollution, sources, and risks in the river-lake system sediments were systematically analysed for cadmium (Cd), chromium (Cr), arsenic (As), mercury (Hg), lead (Pb), copper (Cu), zinc (Zn), and nickel (Ni). The results showed that at least half of the heavy metals in the lakes and rivers exceeded the local soil background values during the flood and dry seasons. Heavy metal concentrations were generally higher in the lakes, with high concentrations in the lakes and nearby rivers. Through positive matrix factorisation and Geodetector traceability discovery, agricultural activities were found to be the main source of heavy metals in river sediments, whereas urban activities were the main source in lake sediments. Ecological risk assessments indicated that Hg and Cd were the main risk factors, causing pollution in lakes due to atmospheric deposition and traffic emissions and moderate pollution in rivers due to atmospheric deposition and agricultural production. Health risk assessments revealed that As and Ni were the main carcinogenic risks, originating from human and industrial activities in lakes, and from agricultural and natural sources in rivers. Children faced higher carcinogenic risks than adults, possibly because of their behaviour and physiology. Overall, the presence of heavy metals, along with their ecological and health risks, was significantly higher in the lakes than in the rivers. This study provides a comprehensive overview of the pollution, sources, and risks of eight heavy metals in the river-lake system of the Dianchi Basin.

Recovering NDVI over lake surfaces: Initial insights from CYGNSS data enhanced by ERA-5 inputs

The escalating water pollution in many lakes has led to more frequent occurrences of algal bloom disasters in recent decades. The severity of these disasters can be assessed through remote sensing techniques, specifically using the Normalized Difference Vegetation Index (NDVI) for measurement. However, NDVI observations using optical sensors are often affected by cloud and fog in areas with numerous water bodies, such as Taihu Lake. Sensors operating in the microwave band can effectively mitigate this issue, particularly the emerging Global Navigation Satellite System Reflectometry (GNSS-R), which offers high temporal resolution and cost-effectiveness. In this paper, we propose a new method to recover lake-surface NDVI on cloudy days, utilizing GNSS-R observables and auxiliary meteorological data in conjunction with a machine learning regression algorithm called Bagging Tree. We also examine the effective range of GNSS-R data within this application scenario. Meanwhile, the Weighted Linear Regression-Laplacian Prior Regulation Method (WLR-LPRM) image gap-filling algorithm is used as a benchmark to evaluate recovery accuracy. The regression coefficient of NDVI retrieved using the proposed method is 0.95, with a root mean square error (RMSE) of 0.021 and a mean absolute error (MAE) of 0.010. Compared to the previous work on GNSS-R algal bloom detection with overall accuracy of 0.82, this work shows significant improvement in both accuracy and utility. The recovery of lake surface NDVI provides detailed insights into algal blooms, including quantifiable metrics such as the amount and spatial distribution, which are crucial for effective monitoring and management. Additionally, the recovered image textures exhibit high clarity and closely resemble the reference NDVI images. Experimental evaluation using simulated and actual cloud blocks indicates the model’s robustness to recover NDVI under varying cloud cover conditions. In summary, this study demonstrates the capability of GNSS-R aided by supplementary data for recovering missing NDVI values on lake surfaces when optical observations are absent for the first time.

Adsorption of Cr(VI) Using Organoclay/Alginate Hydrogel Beads and Their Application to Tannery Effluent.

The tanning industry is among the most environmentally harmful activities globally due to the pollution of lakes and rivers from its effluents. Hexavalent chromium, a metal in tannery effluents, has adverse effects on human health and ecosystems, requiring the development of removal techniques. This study assessed the efficacy of organobentonite/alginate hydrogel beads in removing Cr(VI) from a fixed-bed adsorption column system. The synthesized organobentonite (OBent) was encapsulated in alginate, utilizing calcium chloride as a crosslinking agent to generate hydrogel beads. The effects of the volumetric flow rate, bed height, and initial Cr(VI) concentration on a synthetic sample were analyzed in the experiments in fixed-bed columns. The fractal-like modified Thomas model showed a good fit to the experimental data for the asymmetric breakthrough curves, confirmed by the high R2 correlation coefficients and low χ2 values. The application of organoclay/alginate hydrogel beads was confirmed with a wastewater sample from an artisanal tannery industry in Belén (Nariño, Colombia), in which a Cr(VI) removal greater than 99.81% was achieved. Organobentonite/alginate hydrogels offer the additional advantage of being composed of a biodegradable polymer (sodium alginate) and a natural material (bentonite-type clay), resulting in promising adsorbents for the removal of Cr(VI) from aqueous solutions in both synthetic and real water samples.

Pollution analysis of metals in the sediments of lagoon lakes in Türkiye: Toxicological risk assessment and source insights

This study addresses gaps in understanding the distribution, sources, and health risks of potentially toxic elements (PTEs) in the sediments of lagoon lakes Akgöl and Simenit in Türkiye. Sediment samples from 16 locations were analyzed for Fe, Cu, Mn, Zn, Cr, Ni, As, Pb, Cd, and Hg. Findings indicate higher concentrations of Fe and Mn in Simenit Lake and elevated levels of Cr and Ni in both lakes. The Enrichment Factor (EF), Contamination Factor (CF), and Pollution Load Index (PLI) were used to evaluate contamination levels in sediments, while sediment quality guidelines and the Potential Ecological Risk Index (PERI) assessed ecotoxicological risks. Results reveal moderate to high pollution in Simenit Lake, particularly for Cr and Ni, with Cd posing a significant ecological risk. Health risk assessments showed non-carcinogenic risks (Hazard Index, HI > 1) for children, especially in Simenit Lake (HI = 1.10). Carcinogenic risks from Cr and Ni were within acceptable limits; however, Simenit Lake exhibited higher Total Cancer Risk (TCR) values for Cr (5.40E-05) and Ni (1.37E-04), indicating a low but notable risk. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) identified industrial discharge and agricultural runoff as primary contamination sources. These findings highlight the need for targeted management strategies to mitigate health and ecological risks in these vulnerable aquatic systems.

Microplastic pollution – a rising threat along an urban lake in the Vellore district of Tamil Nadu, India: abundance and risk exposure

ABSTRACT Lake ecosystems provide vital services, but face escalating threats from synthetic microplastic (MP) pollution driven by human activities, necessitating urgent action. This study investigates MP contamination in Dharapadavedu Lake, Tamil Nadu, India, characterizing its presence and distribution. MPs in water and sediment were assessed using NOAA's standardized protocol. The results indicate that mean concentration of MPs in lakeshore sediment and water was 2.46 ± 1.06 particles/kg and 1.26 ± 0.88 particles/L, respectively. Significantly, medium-sized MPs (500–1,000 μm) were most abundant, comprising predominantly white, red, and green colors with fragments and fiber morphotypes. Attenuated total reflection Fourier transform infrared spectroscopy revealed valuable insights into the polymer composition of MPs in the lake, identifying four primary types: nylon (polyamide), high-density polyethylene, low-density polyethylene, and polypropylene. Pollution load index data reveals that MP pollution levels of 2.26 in sediment and 1.46 in water indicate a moderate to high level of risk. These findings reveal that the repercussions of recreational activities, anthropogenic activities, and fishing practices around the lake contributed to the accumulation of MPs in the lake. This study fills a research gap by investigating MP pollution in Dharapadavedu Lake for the first time, establishing a baseline contamination estimate.

Microplastics and their interaction with microorganisms in Bosten Lake water

Microplastic pollution in inland freshwater lakes, formed from melting ice, atmospheric precipitation, and groundwater, remains under-researched. This study examines microplastic (MPS) presence and distribution in Bosten Lake and their interaction with microorganisms. We employed a Confocal Raman spectrometer to identify MPS types and 16S rRNA high-throughput sequencing to analyze microbial diversity and composition. In May, the lake's average microplastic concentration was 108.20 particles per liter (PCS/L), decreasing to 21.67 PCS/L by October. Transparent and yellow fibrous microplastics, predominantly 0.2–0.5 mm in size, were most common. Key microplastics in May included PEEK (27%), PMMA (25%), and PET (9%), while October saw a prevalence of PET (35%), PS (13%), and PA (9%). Higher microplastic concentrations correlated with reduced microbial diversity. In May, the high microplastic concentration group (MH) showed increased Planctomycetota, while in October, Patescibacteria and Bacteroidota rose significantly in the high plastic group (OH), known for microplastic degradation. MH also had a higher abundance of Cryptomycota compared to OH. Functional analysis indicated that MH had more genes related to bisphenol, benzene, and chlorine compounds, whereas OH had genes linked to methane, nitrogen, and organic matter degradation. Microplastic concentrations peaked near the lake inlet and tourist areas, affecting microbial quantity, diversity, structure, and function. This research enhances our understanding of MPS distribution and environmental microbial shifts in similar settings, providing essential data for environmental management strategies at Bosten Lake.

The nitrate cycling process in a through-flow lake under the water transfer project: Insights from multiple isotopes

The Yangtze River-Huai River Water Transfer Project (YHWTP) is the typical inter-basin water diversion project in China. Large-scale hydraulic engineering projects may lead to potential changes in nitrate cycling, yet this aspect remains poorly studied. Therefore, this study focused on the environmental behavior of nitrates in a typical through-flow lake along the YHWTP, using Wabu Lake as an example. Nitrate was the predominant form of nitrogen pollution in the through-flow lake, and may affected by the input of upstream rivers along YHWTP. In addition, we investigated the nitrate transformation process and sources by multiple isotopes (δ18O-H2O, δD, δ15N-NO3-, δ18O-NO3-) of water and nitrate sources samples. The transformation of nitrate mainly involved nitrification in the through-flow lake. Chemical fertilizer (CF) was the major source (33.0–37.6 %) of nitrate pollution, followed by manure & sewage (M&S) (8.2–37.0 %), soil nitrate (SN) (26.5–31.4 %) and atmospheric precipitation (AP) (3.5–22.8 %) in present study. Uncertainties associated with nitrate sources apportionment were analyzed and followed as: CF > M&S > SN > AP. These results offer insights for managing impacted by nitrate pollution in the other water transfer projects.

Effects of climate warming and declining water quality on the eco-environmental evolution of Jinmucuo Lake: Evidence from sedimentary diatom assemblages

The problem of lake pollution on the Tibetan Plateau has become prominent in recent years because of the warming climate and increased human activity. However, it is difficult to obtain effective indicators to explain the long-term eco-environmental changes in plateau lakes. In this study, a sediment core from Jinmucuo Lake was taken as the research object, and the 210Pb and 137Cs isotopes, diatom assemblages, and climatic and environmental factors were analyzed. The results revealed that the lake had a sedimentation rate of 0.47 cm/a, and the age of the 30-cm sediment core was approximately 1876 AD. Diatom abundances at different ages tend to decrease. During 1876–1999, abundant diatom species, such as Cymbella lanceolata, Navicula sp., Surirella ovalis, Synedra sp., Epithemia adnata, Cymbella pusilla, Amphora ovalis and Tabularia tabulata, which included oligotrophic, mesotrophic, and eutrophic indicator species were detected, and the dominant species were Cymbella lanceolata, Navicula sp., Surirella ovalis and Synedra sp. After 2000, diatoms declined dramatically, and were undetected in most samples. Similarly, the species richness and Shannon‒Wiener index plummeted to 0 in approximately 2002. Canonical correspondence analysis revealed that total nitrogen and organic matter were the main influencing factors of diatom assemblages before 2000, whereas As and mean annual temperature were the main influencing factors after 2000. These findings indicate that diatom habitats have been rapidly destroyed by increasing temperatures and As inputs, even in the presence of abundant nutrients in the lake.

Evaluation of Water Quality and Eutrophication of Typical Lakes in Southeast Hubei, China

Field surveys and sample analyses were conducted from January 2018 to December 2019 on Daye Lake, Cihu Lake, Baoan Lake, and Xiandao Lake to understand the water quality characteristics of typical lakes in southeast Hubei. A fuzzy comprehensive evaluation was conducted and the comprehensive trophic level index was applied to evaluate the lakes’ water quality. The results showed differences in the regional, spatial, and temporal distributions of physical and chemical indicators in typical lakes in southeast Hubei. The fuzzy comprehensive evaluation showed that the water quality levels in Daye, Cihu, Baoan, and Xiandao Lakes for 2018 and 2019 were IV, IV, III, and II and V, IV, III, and II, respectively, with seasonal variations in water quality occurring during the year. The trophic level index results showed that Cihu Lake was mildly eutrophic in 2018 and moderately eutrophic in 2019, and Daye, Baoan, and Xiandao Lakes were mildly eutrophic, mildly eutrophic, and mesotrophic, respectively. Lake water quality was influenced by land use types, landscape configuration, inflowing rivers, precipitation, and interactions between land use and seasons. This study helps us to understand the trend and causes of lake pollution in Southeast Hubei, which is conducive to watershed management and the control of water quality deterioration, and also has an important role in regulating the sustainable development of industry and agriculture in the watershed.

Innovative lake pollution profiling: unveiling pollutant sources through advanced multivariate clustering techniques.

In many developed and developing nations, lakes are the primary source of drinking water. In the current scenario, due to rapid mobilization in anthropogenic activities, lakes are becoming increasingly contaminated. Such practices not only destroy lake ecosystems but also jeopardize human health through water-borne diseases. This study employs advanced hierarchical clustering through multivariate analysis to establish a novel method for concurrently identifying significantly polluted lakes and critical pollutants. A systematic approach has been devised to generate rotating component matrices, dendrograms, monoplots, and biplots by combining R-mode and Q-mode analyses. This enables the identification of contaminant sources and their grouping. A case study analyzing five lakes in Bengaluru, India, has been conducted to demonstrate the effectiveness of the proposed methodology. Additionally, one pristine lake from Jammu & Kashmir, India, has been included to validate the findings from the aforementioned five lakes. The study explored correlations among various physical, chemical, and biological characteristics such as temperature, pH, dissolved oxygen, conductivity, nitrates, biological oxygen demand (BOD), fecal coliform (FC), and total coliform (TC). Critical contaminants forming clusters included conductivity, nitrates, BOD, TC, and FC. Factor analysis identified four primary components that collectively accounted for 85% of the overall variance. Following identification of pollution hotspots, the study recommends source-based pollution control and integrated watershed management, which could significantly reduce lake pollution levels. Continuous monitoring of lake water quality is essential for identifying actual contaminant sources. These findings provide practical recommendations for maximizing restoration efforts, enforcing regulations on pollutant sources, and improving water quality conditions to ensure sustainable development of lakes.

Global patterns of lake microplastic pollution: Insights from regional human development levels

Microplastics have emerged as a pervasive pollutant across various environmental media. Nevertheless, our understanding of their occurrence, sources, and drivers in global lakes still needs to be completed due to limited data. This study compiled data from 117 studies (2016–May 2024) on microplastic contamination in lake surface water and sediment, encompassing surface water samples in 351 lakes and lake sediment samples in 200 lakes across 43 countries. Using meta-analysis and statistical methods, the study reveals significant regional variability in microplastic pollution, with concentrations ranging from 0.09 to 130,000 items/m3 in surface water and from 5.41 to 18,100 items/kg in sediment. Most microplastics were under 1 mm in particle size, accounting for approximately 79 % of lake surface water and 76 % of sediment. Transparent and blue microplastics were the most common, constituting 34 % and 21 % of lake surface water and 28 % and 18 % of sediment, respectively. Fibers were the dominant shape, representing 47 % of lake surface water and 48 % of sediment. The primary identified polymer types were polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). Countries like India, Pakistan, and China had higher contamination levels. Positive correlations were found between microplastic abundance in surface water and factors like human footprint index (r = 0.29, p < 0.01), precipitation (r = 0.21, p < 0.05), and net surface solar radiation (r = 0.43, p < 0.001). In contrast, negative correlations were observed with the human development index (r = −0.61, p < 0.01) and wind speed (r = −0.42, p < 0.001). In sediment, microplastics abundance correlated positively with the human footprint index (r = 0.45, p < 0.001). This study underscores the variability in microplastic pollution in global lakes and the role of human activities and environmental factors, offering a valuable reference for future research.

Source identification of organic C and N in suspended particulate matter and sediments in plateau lakes as influenced by trophic status using stable isotopic signatures

Understanding the relationship between suspended particulate matter (SPM), sediment organic C, N stable isotopes, and lake trophic state index (TSI) is essential for managing lake pollution and eutrophication. According to the δ13C, δ15N, and C/N we found that the organic C in SPM and sediment of Caohai Lake primarily originated from macrophytes, while N was sourced from chemical fertilizers, phytoplankton, and aquatic plants. Total nitrogen, total phosphorus, NO3−-N, oxidation reduction potential, and Chl.a were identified as key factors influencing the sources and variations of SPM and sediment organic C and N stable isotopes in Caohai Lake, with a significant linear correlation observed between C, N stable isotopes, and TSI in sediments. To mitigate eutrophication in Caohai Lake, it is recommended that farmers apply fertilizers judiciously to minimize nutrient loss and that aquatic plants be regularly harvested to reduce N release from plant residues.

Morphological responses of ostracods to heavy metal contamination: freshwater ostracods as bioindicators of pollution in Ichkeul Lake and rivers ecosystem, northern Tunisia

Morphological responses of ostracods to heavy metal contamination: freshwater ostracods as bioindicators of pollution in Ichkeul Lake and rivers ecosystem, northern Tunisia

Evaluation of potential adsorbents for simultaneous adsorption of phosphate and ammonium at low concentrations

Evaluation of potential adsorbents to tackle eutrophication caused by low concentrations of phosphate and ammonium are rarely reported in the literature. Besides, the dynamics/mechanisms for removal of these pollutants at low concentration are yet to be explored. In this study we used five different adsorbents, including La-modified zeolite (LMZ), MgFe-modified biochar (MgFe-BC), phoslock, activated alumina (AA), and diatomaceous earth (DE) to evaluate the removal of these pollutants. Among the selected adsorbents in this study, LMZ and AA both exhibited effective and simultaneous adsorption for phosphate and ammonium and the maximum adsorption capacities were 2.47 mg/g and 3.07 mg/g, respectively. The presence of SO42− and CO32− negatively impacted phosphate adsorption, while Fe3+ and K+ ions inhibited ammonium adsorption. LMZ adsorption kinetics was over 3 times faster than other adsorbents within 60 min reaction time. Kinetics studies and isotherms revealed that the removal of phosphate and ammonium was primarily driven by chemical interactions and monolayer adsorption and were better fitted by Langmuir isotherm than the Freundlich isotherm and kinetic study was effectively described by Pseudo-second-order kinetic model. FTIR and XPS analysis revealed that the key mechanisms for phosphate adsorption were electrostatic attraction and inner sphere complexation through ligand exchange, whereas ammonium adsorption was mainly governed by ion exchange. Desorption study revealed that LMZ material was stable after three desorption cycles. This study offers vital knowledge on the nature of adsorption and interactions of potential mesoporous adsorbents with eutrophication-causing pollutants in lakes and rivers and proposes effective remedial mean.