Environmental Science and Pollution Research最新文献

Orphan radioactive sources pose a significant environmental and human health threat. This study presents a novel, scalable detection system for localizing and identifying these sources within large areas. Our system integrates a network of radiation detectors with surveillance cameras, employing data fusion algorithms to analyze both radiological and visual data. This multi-sensor approach enables accurate estimation of radionuclide types and the assessment of associated radiological risks. Real-world experiments demonstrate the system’s effectiveness in enhancing the efficiency and accuracy of orphan radioactive source detection, contributing to improved environmental monitoring and the mitigation of potential radiological contamination risks.

Landfill fires represent a major cause of environmental degradation and pose substantial health risks for the populations residing near the affected sites. This study investigates the characteristics of landfill fire at the Brahmapuram Municipal Solid Waste Treatment Plant (BMSWTP) in Kochi (March 2023) and the role of prevailing meteorology in mitigating its impact. The fire incidents occurred in two phases: the first phase from 04^th to 13^th March and the second phase from 19^th to 28^th March. Analysis indicates that the fire event caused a significant rise in pollution intensity during the first phase, with the increase of PM₂.₅ levels by 152%, PM₁₀ by 175%, and NO₂ and SO₂ by an alarming 440% and 420% compared to normal conditions. During the first phase, pollutants were dispersed towards the coastal ocean by the prevailing easterly wind, mitigating the impact of emissions. Further, the air quality improved by the middle of the month due to the considerable rainfall over the region that helped scavenge the pollutants. Results show that the maximum concentrations of PM₂.₅ and PM₁₀ observed during the early morning hours are attributed to a shallower boundary layer and weak convective potential, resulting in increased atmospheric stability and trapping of pollutants. We document that the pollution from the landfill fire may have affected marine productivity in the southeastern Arabian Sea, as evidenced by the anomalous increase in chlorophyll-a concentrations, without the influence of the oceanic upwelling. The second phase of the landfill fire was characterised by westerly winds, which resulted in the dispersion of pollutants towards inland areas.

Extreme flood events increasingly threaten water quality in agriculturally intensive regions, particularly under accelerating climate change. In September 2023, the Pineios river basin in Thessaly, Greece, the country’s most productive agricultural region, experienced catastrophic flooding caused by Storm Daniel and subsequently Storm Elias. This study investigates the occurrence, distribution, and temporal variation of phthalate esters, alternative plasticizers, per- and polyfluoroalkyl substances (PFAS), and fecal indicator bacteria in surface waters before and after these extreme weather events. A total of 24 sampling locations were monitored across the river basin. Water samples were analyzed using validated targeted screening methods based on gas or liquid chromatography tandem mass spectrometry (GC- or LC-MS/MS), while microbial contamination was assessed using International Organization for Standardization (ISO) compliant culture–based techniques. Results revealed widespread contamination by both legacy phthalates, particularly di(2-ethylhexyl) phthalate (DEHP, median concentrations up to 0.36 µg/L), di-n-butyl phthalate (DnBP, 1.9 µg/L) and dimethyl phthalate (DMP, 3.5 µg/L), and emerging alternative plasticizers, such as di(2-ethylhexyl) terephthalate (DEHT, 0.15 µg/L), which was the most abundant of the emerging compounds. Statistically significant post-flood increases (p < 0.05) were observed at several estuarine sites, with total median plasticizer concentrations reaching up to 5.4 µg/L. Among 63 monitored PFAS, 13 compounds were consistently detected across all samples. These included perfluorooctanoic acid (PFOA, median up to 0.47 ng/L), perfluorooctanesulfonic acid (PFOS, 0.2 ng/L), and 6:2 fluorotelomersulfonic acid (6:2 FTS, 1.7 ng/L). Concentrations for PFAS regulated groups, namely PFAS-4 and PFAS-24, frequently approached or exceeded proposed EU water quality thresholds. Fecal indicator bacteria, including Escherichia coli and Enterococcus spp., frequently exceeded the EU bathing water standards, particularly near wastewater discharge points and areas affected by agricultural flooding. Peaks in contamination were linked to carcass decomposition, damage to wastewater treatment infrastructure, and surface runoff following the flood events. These findings highlight the vulnerability of Mediterranean river basins to complex pollutant mixtures following extreme weather phenomena. The study provides novel regional data and emphasizes the urgent need for integrated environmental monitoring aligned with One Health principles to inform future regulation and management of emerging contaminants in flood-prone areas.

Graphical Abstract

Groundwater serves as the main supply source of water for domestic, drinking, industrial, and agricultural uses. This study assessed the groundwater quality and associated health risks in the Kathmandu Valley. In total, 401 groundwater samples from Lalitpur (299), Kathmandu (82), and Bhaktapur districts (40) were collected from 14th April 2022 to 13th April 2023. The water quality parameters, including pH, electrical conductivity (EC), turbidity (Tur), total hardness (TH), chloride (Cl), nitrate (NO₃⁻), ammonia (NH₄⁺), and iron (Fe) were analyzed. Groundwater quality index, spatial analysis techniques including geographic information systems (GIS), multivariate analysis, and machine learning approach by self-organizing maps (SOM) with hierarchical clustering analysis were employed to identify areas of concern. The results revealed elevated levels of turbidity, NH₄⁺, and Fe in several regions, particularly in urban and semi-urban areas. The nitrate pollution index (NPI) and ammonia pollution index (API) analyses revealed 0.99% and 31.42% of high nitrate and ammonia pollution, respectively. Health risk assessment indicated potential risks, especially for infants, due to exposure to nitrate and ammonia. Principal component analysis (PCA) primarily demonstrated the ion concentration and mineralization, which are affected by both natural geological processes and anthropogenic activities. The groundwater samples were grouped into five clusters using hierarchical clustering after SOM classification highlighted the areas affected by NH₄⁺ and Fe. The study highlights the need for effective groundwater management strategies to mitigate groundwater contamination and protect public health in the Kathmandu Valley.

Cometabolic oxidation is a process in which compounds, including groundwater pollutants such as halogenated aliphatics, are fortuitously oxidized by enzymes with broad substrate specificity. Assessing the magnitude of cometabolic oxidation in contaminated environments is challenging; however, it may be facilitated using Compound-Specific Isotope Analysis. Our former work on the cometabolic oxidation of trichloroethene (TCE) revealed a unique isotope pattern when the process was catalyzed by several methanotrophs rather than by toluene and ammonia oxidizers. In the current work, we aimed to study isotope effects in the cometabolic oxidation of other halogenated compounds of environmental interest by the methanotroph Methylosinus trichosporium OB3b. Results showed relatively small carbon isotope fractionation for cis-dichloroethene (cDCE; AKIE = 1.0017 ± 0.0016) and bromoform (BF; AKIE = 1.0020 ± 0.0014), which are similar to formerly determined value for TCE. Larger carbon isotope effects were recorded for chloroform (CF; AKIE = 1.0038 ± 0.0007) and dichloromethane (DCM; AKIE = 1.0043 ± 0.0009), possibly implying a decrease in the role of enzyme binding as a bottleneck for these two. Nevertheless, while DCM presented both relatively large carbon isotope effects and rapid degradation, CF presented relatively large carbon isotope effects but degraded slower than cDCE and TCE. This is possibly related to the reported toxicity of CF’s byproducts, which reduces the overall degradation rate.

Anaerobic digestion is an effective technology for converting organic waste into biogas while reducing environmental pollution. This study investigates the impact of co-digesting waste-activated sludge (WAS) with wheat straw, rice straw, and bokashi on biogas production. Nine anaerobic batch reactors were operated under mesophilic conditions (35 °C), incorporating different proportions of bokashi (1% and 2%) along with rice and wheat straw (4%). The results revealed that reactors supplemented with wheat and rice straw exhibited higher biogas production than the control reactor (sludge only). Wheat straw outperformed rice straw in improving biogas yield, total solids (TS) reduction, total volatile solids (TVS) degradation, and chemical oxygen demand (COD) removal. The addition of bokashi enhanced biogas production, confirming its role in accelerating organic matter breakdown. The maximum biogas yield was observed in the reactor containing sludge co-digested with wheat straw and 2% bokashi, which generated three times more biogas than the control. This reactor also exhibited the highest degradation rates of TS (57.83%), TVS (66.37%), and COD (71.53%). Furthermore, pH remained stable within the optimal range across all reactors, ensuring a balanced digestion process. Statistical analysis revealed significant correlations between organic matter degradation (COD, TS, TVS reduction) and biogas production, demonstrating that effective substrate decomposition improves biogas yield. The recurrent neural network (RNN) model was applied to experimental data to predict biogas production. With an exceptionally low root mean square error (RMSE) of 0.0041, R² close to 1, and MAE 0.0117, the model exhibited excellent accuracy and reliability in generating precise predictions.

In recent years, soil salinity has posed a significant challenge to greenhouse vegetable cultivation in Iran. Nowadays, bioremediation is an innovative and up-and-coming method for soil salinity remediation; it offers several advantages including high efficiency, economic efficiency, environmental compatibility, sustainability, and improved biodiversity. Biological remediation strategies are based on the synergistic effects of biological agents such as halophyte PGP bacteria and environmentally friendly materials such as biopolymers to improve saline soil health. The aim of this study was to evaluate the encapsulation of halophyte PGP bacteria with chitosan, alginate, and starch biopolymers on soil chemical properties, soil enzyme activity, and their potential functions for purslane phytoremediation by simulation in Plexiglas columns in saline soil remediation. The treatments included a consortium of eight halophyte PGP bacteria (the same eight-strain halotolerant PGPR consortium was used consistently across all treatments), two types of microencapsulation, including Alginate + Starch + Chitosan and Starch + Chitosan in the biopolymer structure, compared to the conventional method using 1% H₂SO₄. The saline soil column leaching experiment was conducted on the dynamics of salt distribution, desalination efficiency, and leaching rate. The chemical properties and content of soil enzymes were examined before and after the experimental treatments. The results revealed that the biopolymer amendments reduced the content of Na⁺, CO₃²⁻, HCO₃⁻, and Cl⁻ and significantly (p < 0.01) elevated the content of Ca²⁺, Mg²⁺, and K⁺ compared to 1% H₂SO₄. The activities of urease, catalase, dehydrogenase, alkaline phosphatase, and amylase enzymes in soils treated with biopolymer improvers increased significantly ((p<0.01)) compared to 1% H₂SO₄. Biopolymers enhance the adaptability of purslane and PGP bacteria in bioremediation by regulating soil enzymatic activity. However, the conventional 1% H₂SO₄ method stresses microbes and degrades soil health by lowering pH and depleting resources.

Graphical Abstract

The growing presence of new pollutants in the environment could lead to both direct and indirect water contamination, endangering human and marine health life. Pharmaceutical contaminants are becoming more prevalent in the environment due to their persistence and therefore there is urgent attention to develop necessitating technological interventions to eliminate them. Metal–organic frameworks (MOFs) are a type of crystalline material with a large surface area, significant pore size, and strong chemical structure in environmental settings. Research interest in MOFs has increased recently, as they have proven to be effective in removing pharmaceutical pollutants through the adsorption process. This review highlights the effectiveness of various MOF architectures in removing pharmaceutical pollutants from aqueous environments. The review further elaborates on different synthesis methods, functionalization techniques, and adsorption mechanisms in detail. The study reveals that while there has been significant research on the adsorption of antibiotics and anti-inflammatory agents from water using MOFs, there is a lack of information on other types of pharmaceutical agents that also pose risks to human health in the environment. Moreover, the study reports for the first time detailed literature on the adsorptive removal of antibiotics and anti-inflammatory pollutants from water during the period 2015 to 2024. The current review suggests that more attention should be given to phytonanoparticle-MOF nanocomposites for pharmaceutical waste removal, as this could lead to innovative solutions for water purification systems.