Sediment Pollution Research Articles

Seasonal assessment of surface water and sediments pollution in Rachiine River, Northern Lebanon, using multivariate statistical analysis

Urbanization has caused severe negative impacts on intra-urban river water worldwide. In this study, the WHO drinking water standards (2024) were used as reference to assess the physicochemical properties, heavy metals (HMs) content and microbial load in water and sediment samples collected from 25 locations along Rachiine River, located in Northern Lebanon, during wet and dry periods. Multivariate statistical analysis was applied to evaluate the seasonal variations in water and sediment quality, and determine the pollution sources. The microbial load assessment indicated high pollution levels by Escherichia coli, fecal enterococci, total coliform and fecal coliform, which generally increased as the river progressed downstream. Cluster analysis (CA) provided three major clusters in the study region, representing the northern, central, and southern sectors of the river. Principal components analysis (PCA) of water samples generated four principal components (PCs) accounting for 64.3, 11.4, 7.6 and 4.1 % of the total variance, whereas PCA of sediment samples explained 59.1, 16.9 and 11.1 % of the data set variance. These PCs revealed that the quality of water and sediments is significantly impacted by point and diffuse sources, including geological and anthropogenic factors. These findings call for urgent management strategies to limit future deterioration of the aquatic bodies.

Low incidence of microplastics in coral reefs of Kāneʻohe Bay, Hawaiʻi, USA

This study investigated microplastic and other micro-debris pollution in sediment, seawater, sea cucumbers, and corals from fringing and patch reefs in Kāneʻohe Bay, Oʻahu, Hawaiʻi, USA. Microplastic pollution in Kāneʻohe Bay Bay was low compared to other tropical coral reefs. Microplastics were detected in sediments (29 %), sea cucumbers (9 %), and coral (0–2 %) samples but were not quantifiable. Seawater had quantifiable microplastic (< 0.5 mm) and macroplastic (> 0.5 mm) pollution, with mean concentrations ranging from 0.0061 to 0.081 particles m−3. Most particles detected in seawater samples were larger, floating plastic debris consisting mostly of polyethylene, polypropylene fragments, and fibers. Across the other matrices, the most detected particles were polyester, polypropylene, and cotton fibers. These results provide baseline data for this important coral reef ecosystem, and further monitoring is recommended to understand the seasonal and long-term trends in microplastic pollution and its potential future impacts.

Multivariate Statistical Approach and Assessment of Pollution of Water and Sediments in Karstic Springs of Transboundary Aquifer Žumberak–Samoborsko Gorje Mountain (Croatia/Slovenia)

This study highlights the geochemistry of water and sediments of the karstic springs of the transboundary aquifer (TBA) Žumberak–Samoborsko Gorje Mt. (NW Croatia). After calculating pollution indices, the analysis showed that the sediments are unpolluted. The geo-accumulation index (Igeo) showed only the elements Ba and Rb, indicating moderate levels of pollution, with the highest values in springs Vapnik and Bistrac. Statistical analysis confirmed their natural origin. The water of these springs is under possible anthropogenic influence as indicated by elevated concentrations of total nitrogen (TN) and total phosphorus (TP). According to a principal component analysis (PCA) for elements in sediments, PC1 described a combined lithogenic and oxidative–reductive influence, PC2 described a combined geological background including total organic carbon (TOC) content and oxidative–reductive influence, while TOC had the greatest influence on PC3. Depending on element composition, the factor scores related to PC1 and PC2 resulted in two different groups of sites, while the factor scores concerning PC1 and PC3 did not show separation in two groups. The hierarchical cluster analysis showed three clusters in relation to the content of the elements. The correlation coefficient between the sediment and related water samples showed that the springs placed in a low-permeability formation (dolomite) had a strong positive coefficient of correlation.

Distribution and co-occurrence of microplastics and co-existing pollutants in bottom water and sediment of the East China Sea

Microplastics (MPs) contamination in marine environment has been an emerging issue worldwide, notably due to the potential ecological risks of MPs with co-existing environmental contaminants and released toxic plastic additives. To verify the co-occurrence characteristics of MPs and co-existing pollutants in the benthic boundary layer (BBL), the distribution characteristics of MPs, and selected heavy metals (HMs) and halogenated flame retardants (Polybrominated diphenyl ethers, PBDEs, and Dechlorane Plus) in the bottom water and sediment were comprehensively investigated in the East China Sea (ECS). The sampling sites were selected along the coast of ECS, where might be significantly affected by terrigenous inputs and anthropogenic sources. MPs were abundant in the bottom water (62.8–480.2 items/L) and sediment (80.1–1346.7 items/kg d.w.) with polyester, polyethylene, and polypropylene being as the most abundant types and characterized as fiber/line, particle size 200–500 μm, and transparent/white. The abundance and characteristics of MPs demonstrated strong correlations within the bottom water and sediment, which might be due to the frequent exchange of materials. In addition, the abundance of MPs was significantly positively correlated with HMs (Cd, Cr, Pb) in the bottom water and PBDEs in sediment, respectively. According to the scanning electron microscopy/energy dispersive X-ray spectrometry analysis, MPs might act as carriers to transport and co-sediment the co-existing pollutants in water, and physically adsorb or chemically bind with pollutants in sediment. These results could help to elucidate the sources, migration, and fate, and verify the occurrence and potential risks of MPs and their co-existing pollutants in BBL, thus realize the management and control of MPs contamination in marine.

Dioxin-like and estrogenic activity screening in fractionated sediments from a German catchment after the 2021 extreme flood

BackgroundThe flood in July 2021 is considered one of the largest flood disasters in Western Europe in decades, with massive socio-economic consequences. The potential emission and remobilization of anthropogenic pollutants can lead to additional environmental consequences, which need to be addressed in long-term mitigation strategies. The Inde River and its tributary, the Vichtbach River, form a catchment located at the transition from the low mountain ranges of the Eifel to the lowlands of the Lower Rhine Embayment in Germany. The area has been an industrial and mining hotspot for centuries, making it a high-risk area for flood sediment pollution. The present study provides an ecotoxicological screening of flood sediments of the Vicht–Inde catchment to gain an impression of the degree of contamination by organic pollutants by means of in vitro effect-based method. Sediment samples were collected within days after the flood and fractionated prior to biotesting, and supportive instrumental geochemical analysis was performed.ResultsFlood sediments did not reveal estrogenic potential, which was included in the testing strategy as a relevant endpoint for industrial chemicals and untreated wastewater. In contrast, moderate-to-high dioxin-like activity was observed in 70% of the sediment samples with a peak dioxin-like potential at the restored section of the Inde. Overall, four hotspot samples were identified as at risk, which aligned mostly with the high concentration of organic pollutants including PAHs and PCBs. The fractionation allowed the identification of PAHs and their derivates as the most likely toxicity drivers for dioxin-like activity in the sediments of the Vicht–Inde catchment.ConclusionThe results provide first information on the prioritization of hotspot locations at risk for a detailed ecotoxicological profiling and a post-flood monitoring of organic contamination. The identified sinks of contamination in the floodplain areas can be considered a source for remobilization of pollution in future flood events, which is highly relevant for the receiving Rur River.

Organochlorine pesticides and polychlorinated biphenyls in sediments of the Lanzhou reach of Yellow River (China): Spatial distribution, sources and risk assessment

Knowledge about sediment levels and sources of persistent organic pollutants (POPs) in Lanzhou section Yellow River remains limited. Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) levels in 12 sediment samples from this region were measured by GC/MS. OCPs concentrations ranged from 85.6 to 202 ng/g, while PCBs levels varied between 3.08 and 32.3 ng/g. Our findings demonstrated a significant correlation between these pollutants and total organic matter (TOC), highlighting TOC's role in pollutants distribution. Notably, OCPs and PCBs levels were higher in the eastern section, following the water flow direction. The primary OCPs components were hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), whereas PCBs were dominated by perchlorinated compound. Source identification indicated that OCPs primarily originated from historical residues and recent applications, while industrial activities as significant PCBs sources. Sediment quality guidelines and health risk assessments indicated negligible environmental risk. This study providing valuable insights on sediment pollution control and management strategies.

Microplastics pollution in sediments of the Thames and Medway estuaries, UK: Organic matter associations and predominance of polyethylene

Microplastics at 10 sites along a 77 km transect of the river Thames estuary (UK) and 5 sites along 29 km of the Medway estuary were separated from sediment and analysed by ATR-FTIR spectroscopy. Microplastics were observed at all sites. Highest Thames concentrations were in urban London between Chelsea and West Thurrock (average 170.80 particles kg−1 ± 46.64, 3.36 mg kg−1 ± 1.79 by mass), mid-outer estuary sites were two to three times lower. Microplastics were slightly dominated by particles (54 %) over fibres (45 %), including polymer types ranked: polyethylene > PET > polypropylene > polyamide. Medway microplastics decreased seaward, with one urban-municipal site impacted by a combined-sewer-overflow containing a high proportion of fibres (Rochester, 484 particles kg−1, 7.39 mg kg−1 by mass). Microplastic abundance was correlated to organic carbon (TOC %) (R2 of 0.71 Thames and 0.96 Medway), but not sediment particle size. Sedimentary microplastics accumulation in the Thames was controlled by urbanisation-distance, and site hydrodynamics.

Potential use of gammarus (Pontogammarus maeoticus) and shrimp (Palaemon elegans) as biomonitors of microplastics pollution in coastal environments

Microplastics (MPs) pose a significant threat to marine ecosystems, necessitating robust biomonitoring to assess aquatic risks and inform effective policymaking. In this study we investigated MPs pollution in gammarus (Pontogammarus maeoticus), shrimp (Palaemon elegans), sediment and water samples of southern coast of the Caspian Sea to assess the potential use of these two crustaceans as biomonitors of MPs pollution, bioconcentration of MPs in organisms’ tissue and the pollution risks of MPs in environmental matrices. Samples were collected from 6 stations during June to August 2023. MPs were found in all compartments with an average of 100 ± 45.34 items/kg dry weight, 0.45 ± 0.06 items/L, 0.38 ± 0.21 items/individual or 0.58 ± 0.34 items/g wet weight (ww) and 0.26 ± 0.15 items/individual or 8.69 ± 7.88 items/g ww, for sediments, seawaters, P. elegans and P. maeoticus, respectively. MPs were prevailed by class 300−1000 μm in size, polyamide in polymer, fiber in shape and black in color. P. maeoticus and P. elegans did not meet the selection criteria as MPs biomonitors. However, bioconcentration factor (BCF) illustrated that both crustaceans can absorb and accumulate MPs from their surrounding water (BCF >1). Based on contamination factors (CF) values, sampling stations were polluted with MPs (1 ≤ CF < 6). The overall pollution load index (PLI) for sediment and seawater stations were 2.47 and 1.88, respectively, indicating minor contamination with MPs in the risk level I. Current research provides useful information on MPs pollution in crustaceans species and the risk level of MPs in environmental matrices that can be suitable for bioaccumulation hazard assessment and future monitoring programs.

The effects and mechanism of organic matter degradation in river sediment driven by humic-reducing bacteria

The reduction of organic pollutants in sediments is essential for controlling the rebound of black-odor waterbodies. Humic-reducing bacteria are promising in the anaerobic remediation of river sediments. However, the material conditions and environmental factors influencing organic matter (OM) degraded by humic-reducing bacteria in river sediment remain unclear. In this study, humic-reducing bacteria agents (HRBs) were used to remediate sediments with different contamination levels. The result indicated that HRBs remove light fraction organic matter (LFOM) in sediment with a high active organic matter (ATOM) content and can remove heavy fraction organic matter (HFOM) in sediment with a high degree of humification. Correlation analysis showed that OM removal was significantly correlated with fluorescein diacetate (FDA) hydrolase activity (R = 0.89, P ≤ 0.01) and acidified volatile sulfides (AVS) content (R = 0.81, P ≤ 0.05), respectively. Combined analyses of changes in iron morphology and FDA hydrolase activity revealed that HRBs mediated the reduction process of iron minerals, leading to an increase in Fe(II) content in sediment. HFOM complexed with iron minerals was released and could be further decomposed and utilized by FDA hydrolases. In addition, the process of OM degraded by HRBs can induce the accumulation of Fe(II) and AVS. The work helps to understand the mechanism of OM degraded by HRBs in sediment and the applicable conditions for the effective removal of OM by HRBs to control the rebound of black-odor waterbodies caused by endogenous pollution.

Metal pollution in sediments along the Montenegrin coast, Adriatic Sea: a risk analysis

Metal pollution in sediments along the Montenegrin coast, Adriatic Sea: a risk analysis

Unveiling heavy metal pollution dynamics in sediments of river Ulhas, Maharashtra, India: a comprehensive analysis of anthropogenic influence, pollution indices, and health risk assessment.

Metals and metalloids tainting sediments is an eminent issue, predominantly in megacities like Mumbai and Navi Mumbai, requiring an exhaustive examination to identify metal levels in river bodies that serve various populations. Thus, utilising pollution indices, multivariate analysis, and health risk assessment studies, we propose a novel investigation to examine the metal content in the Ulhas River sediments, a prominent agricultural and drinking water supply (320 million-litre per day) near Mumbai in Maharashtra, India. The eleven metals and metalloids (As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn) were examined monthly from 10 stations totaling 120 sediment specimens from October 2022 to September 2023. Investigations revealed that average values of Cr, Cu, Hg, and Ni exceeded Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council values, while all metals exceeded World surface rock average limits except As. Various pollution indices showed that upstream sites had noneto low levelcontamination, whereas downstream locations had moderate to considerablecontamination, suggesting anthropogenic influences. Furthermore, multivariate analysis including correlation, cluster, and principal component analysis identified that sediment pollution was mostly caused by anthropogenic activities. Lastly, health risk assessment indicated Fe was non-carcinogenic to children, whereas Cr and Ni were carcinogenic to children and adults, with children being more susceptible. Thus, from the findings of the study it is clear that, despite low to moderate pollution levels, metals may have significant repercussions, thus requiring long-term planning, frequent monitoring, and metal abatement strategies to mitigate river contamination.

Screening of Characteristic Pollutants and Risk Pollutants in Different Media in the Yangtze River Basin Using Comprehensive Evaluation and Risk Quotient Methods

A variety of pollutants have frequently been detected in the Yangtze River Basin with the rapid economic development, the population increase, and the acceleration of urbanization, which threaten the aquatic ecosystem and human health. A multi-criteria comprehensive evaluation method was developed to identify the characteristic pollutants, and the risk quotient method was used to derive the risk pollutants in water and sediment samples in this article. A total of 155 pollutants from 11 categories were detected in the Yangtze River Basin according to the literature research. Then, the K-means method was used to analyze the cluster of pollutant comprehensive scores. All pollutants were graded based on their scores and recorded as Ⅰ-Ⅵ according to the number of cases in each cluster. A total of 43 pollutants with high scores of Ⅰ and Ⅱ were listed as the characteristic pollutants, which included 11 polycyclic aromatic hydrocarbons, 11 organochlorine pesticides, 10 polychlorinated biphenyls, eight dioxins, two heavy metals, and one phthalate ester. The top five median concentrations of contaminants in water and sediment samples were heavy metals, polycyclic aromatic hydrocarbons, phthalates esters, bisphenols, and pharmaceuticals and personal care products. According to the principle of risk maximization, the risk entropy value （RQ） was calculated based on the highest pollutant concentration. A total of 38 risky pollutants were screened in the water samples （RQ ≥ 0.1）. There were eight high-risk pollutants with RQ ≥ 1, which included benzo[a,h]-anthracene, anthracene, benzo[a]anthracene, pyrene, methoxychlor, aldrin, 2,4'-dichlorodiphenyl, and cadmium. There were 15 high-risk contaminants in the sediment, which included benzo[b]fluoranthene, anthracene, acenaphthene, fluoranthene, cadmium, lead, chromium, arsenic, selenium, dibutyl phthalate, dimethyl phthalate, diisobutyl phthalate, norfloxacin, perfluorobutyric acid, and bisphenol A. The risk pollutants contained emerging pollutants, which included ten pollutants in water samples and nine pollutants in sediments. Antibiotic pollutants accounted for the largest proportion of these emerging pollutants. The information provided in this article may be useful for the relevant departments to monitor the pollutants and propose management programs for the Yangtze River Basin. Additionally, it is of great significance for the ecological environmental protection and management of the Yangtze River Basin.

Uncovering sediment pollution sources: A comparative assessment of two South African Estuaries

Richards Bay Harbour is South Africa's largest and busiest deep-water port by tonnage, and this ongoing shipping and port activities will expectedly result in metal contamination issues. The adjacent Mhlathuze Estuary is a nature reserve with a long history with Richards Bay Harbour and may be prone to metal contamination from multiple sources. The study investigates the sources of contaminated sediments in these two South African estuaries arising from their proximity to various anthropogenic activities. Investigating these sources of contamination is crucial for developing effective pollution control strategy since Richards Bay Harbour and Mhlathuze Estuary are regarded as estuaries of national conservation importance in South Africa. To provide further insights, sediment samples were acid digested and quantified for metal concentrations using Inductively coupled plasma-optical emission spectrometry (ICP-OES). Multivariate (SIMPROF and cluster) analysis was used to identify how sampling sites in Richards Bay Harbour and Mhlathuze Estuary were grouped based on sediment metal concentrations. Results of pollution load index for Richards Bay Harbour showed site 4 to be heavily polluted, while site 3 in Mhlathuze Estuary showed moderate pollution. Multivariate analysis (SIMPROF and cluster) further revealed sites related to anthropogenic activities and those that were unpolluted. Engaging this advanced analysis enhanced the ability to delineate potential pollution sources and further helped in the identification of the main contributors to sediment pollution. The findings indicate that port and industrial activities are the major contributors to sediment contamination at the estuaries. The results provide specific insights into the sources of pollution, informing targeted environmental management and policy-making efforts to protect and improve the estuarine environments.

Пылегрязевые отложения как индикатор эколого-геохимического состояния территории арк­тического города

Urban surface deposited sediments are considered as an indicator of the ecological and geochemical state of the city of Murmansk. The authors have determined regularities that link mineral, chemical and granulometric composition of sediments into a single system; and characterized environmentally significant aspects of contemporary urban sediment genesis. It is shown that pollution and granulometric differentiation of sediments cause increased accumulation of some heavy metals in dust and mud sediments. The formation of sediment accumulations in relief depressions becomes a source of fine particles entering the atmosphere.

Utilizing machine learning to evaluate heavy metal pollution in the world's largest mangrove forest

The world's largest mangrove forest (Sundarbans) is facing an imminent threat from heavy metal pollution, posing grave ecological and human health risks. Developing an accurate predictive model for heavy metal content in this area has been challenging. In this study, we used machine learning techniques to model sediment pollution by heavy metals in this vital ecosystem. We collected 199 standardized sediment samples to predict the accumulation of eleven heavy metals using ten different machine learning algorithms. Among them, the extremely randomized tree model exhibited the best performance in predicting Fe (0.87), Cr (0.89), Zn (0.85), Ni (0.83), Cu (0.87), Co (0.62), As (0.68), and V (0.90), achieving notable R2 values. On the other hand, the random forest outperformed for predicting Cd (0.72) and Mn (0.91), whereas the decision tree model showed the best performance for Pb (0.73). The feature attribute analysis identified FeV, CrV, CuZn, CoMn, PbCd, and AsCd relationships resembled with correlation coefficients among them. Based on the established models, the prediction of the contamination factor of metals in sediments showed very high Cd contamination (CF ≥ 6). The Moran's I index for Cd, Cr, Pb, and As were 0.71, 0.81, 0.71, and 0.67, respectively, indicating strong positive spatial autocorrelation and suggesting clustering of similar contamination levels. Conclusively, this research provides a comprehensive framework for predicting heavy metal sediment pollution in the Sundarbans, identifying key areas needing urgent conservation. Our findings support the adoption of integrated management strategies and targeted remedial actions to mitigate the harmful effects of heavy metal contamination in this vital ecosystem.

Mud and organic content are strongly correlated with microplastic contamination in a meandering riverbed

The scale of microplastic pollution in river sediments is gradually being elucidated through an increasing number of large-scale studies. Nevertheless, microplastic distribution within a riverbed – a crucial aspect for quantification – remains poorly understood. Here we evaluate in the meandering River Lys, Belgium, how microplastic concentration varies between different sedimentary environments within the riverbed. We find that microplastic abundance is about an order of magnitude higher towards the riverbanks compared to the thalweg, corresponding with river hydrodynamics. Moreover, organic-matter and mud content are robust predictors of microplastic concentrations, apart from the outer bends, where erosion into organic-rich, muddy floodplain sediments inhibits microplastic deposition. These results increase our understanding of microplastic distribution at the small riverbed scale. They are a crucial element to guide for future sampling efforts across diverse river systems, paving the way for normalization and better quantification of microplastics trapped by river sediments and in other aquatic environments.

Distribution, ecological risk assessment, and source identification of potential toxic elements (PTEs) in Muttukadu backwater sediments, Southern India

Muttukadu Backwater is a robust estuary on the east coast of Tamil Nadu is contaminated by industrial, residential, and tourism-related activity (especially boat houses). In this present research, we investigated the heavy metal pollution, spatial distribution and statistical analysis of muttukadu coastal sediments, east coast of the Bay of Bengal in south India. In this study, we present the distribution of heavy metals in backwater sediments reveals enhanced levels of Fe, Mn, Cr, Zn, Cu, Ni, Pb, and Co and the highest concentrations of these metals are found at stations 2, 4, and 8. Based on contamination indices such as CD, Igeo, and PLI, moderate contamination is clear evident. However, the present data of Cr, Cu, and Pb metals have indicated low to moderate anthropogenic influence. We have identified the metals of Cr, Cu, and Pb indicated the High habitat risks are highlighted by ecological risk assessments, and it is due to the anthropogenic factors. Cu, Mn, Zn, and Cr are sourced from anthropogenic sources, while Pb, As, Co, and Ni originate from natural sources, according to spatial distribution analysis. A significant disturbance to the aquatic environment is caused by human activity. In this present study, underscores the necessity of pre-flooded dataset for future comparative research and ecological conservation in Muttukadu Backwater and their environments.

COVID-19 lockdown measures affect polycyclic aromatic hydrocarbons distribution and sources in sediments of Chaohu Lake, China

The COVID-19 pandemic has profoundly impacted human activities and the environment globally. The lockdown measures have led to significant changes in industrial activities, transportation, and human behavior. This study investigates how the lockdown measures influenced the distribution of polycyclic aromatic hydrocarbons (PAHs) in the sediments of Chaohu Lake, a semi-enclosed lake. Surface sediment samples were collected in summer of 2020 (lockdown have just been lifted) and 2022 and analyzed for 16 priority PAHs. The range of ΣPAHs concentrations remained similar between 2020 (158.19–1693.64 ng·g−1) and 2022 (148.86–1396.54 ng·g−1). Among the sampling sites, the west lake exhibited similar PAHs concentrations characteristics over the two years, with higher levels observed in areas near Hefei City. However, the east lake exhibited increased ΣPAHs concentrations in 2022 compared to 2020, especially the area near ship factory. PAHs source analysis using principal component analysis-multiple linear regression (PCA-MLR) revealed an increased proportion of petroleum combustion sources in 2022 compared to 2020. The isotope analysis results showed that organic matter (OM) sources in the western lake remained relatively stable over the two years, with sewage discharge dominating. In contrast, the eastern lake experienced a shift in OM sources from sewage to C3 plants, potentially contributing to the increased PAH levels observed in the eastern lake sediments. Ecological risk assessment revealed low to moderate risk in both 2020 and 2022. Health risk evaluation indicated little difference in incremental lifetime cancer risk (ILCR) values between the two years, with only benzo[a]pyrene (BaP) posing a high risk among the carcinogenic PAHs. Children generally faced higher health risks compared to adults. This study reveals pandemic-induced changes in PAH pollution and sources in lake sediments, offering new insights into the impact of human activities on persistent organic pollutants, with implications for future pollution control strategies.

Assessing the impact of heavy metals on bacterial diversity in coastal regions of Southeastern India.

Globally, there is growing concern over the environmental contamination of coastal ecosystems caused by anthropogenic activities. Here,we performed a study to evaluate the degree of heavy metal contamination in 5 different sediment samples collected from five sites along the Southeastern coast of India. Additionally, the research aims to explore the potential ecological implications of heavy metal contamination on the bacterial diversity, a crucial factor in upholding a sustainable ecosystem. A total of seven heavy metals, i.e., chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As), were assessed and quantifiedusing inductively coupled plasma mass spectrometry. Targeted amplicon sequencing revealed that phylum Proteobacteria (36.9%) was the most dominating followed by Halobacterota (25.5%), Actinobacteriota (15%), Firmicutes (6.7%), Bacteroidota (4.0%), Thermoplasmatota (2.3%), Acidobacteriota (2.0%), Chloroflexi (1.6%), Planctomycetota (1.2%) and Crenarchaeota (1.1%). According to the alpha diversity estimate, lesser bacterial diversity was observed in areas with high pollution levels. Moreover, the physicochemical parameters of the sediments were analyzed. The contamination levels of the sediments were evaluated using the geo-accumulation index (Igeo), contamination factor (CF) and pollution loading index (PLI) to ascertain the comprehensive toxicity status of the sediments. TheIgeo values revealed sediment pollution with metals such as Hg and Cd. The sediments obtained from the sampling site PU-01 showed the highest concentration of Hg pollution. Considering the ecotoxicological aspect, theestimated risk index (RI) values indicated a range from low to significant ecological risk.

Experimental study on different phytoremediation of heavy metal pollution in HDS sediment of copper mines

Experimental study on different phytoremediation of heavy metal pollution in HDS sediment of copper mines