环境•农林最新文献

The increasing use of plastics containing chemical additives such as persistent organic pollutants (POPs) has emerged as a significant environmental and public health concern. These substances, once deliberately incorporated during manufacturing, were later banned under the Stockholm Convention due to their toxic, persistent, and bio-accumulative nature. Despite global bans, certain POPs are still unintentionally generated and released during plastic production, recycling, and disposal. Their presence throughout the plastic lifecycle ranging from manufacturing to use and final disposal raises serious environmental and health concerns. POPs can be emitted into the environment not only through poor waste management and open dumping but also during the use phase of plastic products, such as through indoor dust in households and offices. Inadequate waste handling further contributes to their spread into various environmental compartments such as air, water and soil. This review provides a comprehensive understanding of the emergence and occurrence of POPs in plastic polymers across different environmental matrices. It also uniquely integrates historical evolution, sector-wise emission pathways, and bibliometric trends to underscore the POP dynamics in India’s environmental context.

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Seaweed has garnered significant attention as a sustainable and efficient biosorbent for removing heavy metals from wastewater, offering a low-cost and eco-friendly alternative to conventional treatment methods. However, despite increasing research interest, substantial gaps remain in understanding the large-scale applicability, adsorption mechanisms in multi-contaminant systems, and long-term sustainability. Furthermore, studies on biosorbent modification techniques, process optimization, and techno-economic feasibility assessments are limited, hindering the transition from laboratory research to industrial-scale applications. To address these gaps, this study conducts a bibliometric analysis using R’s Biblioshiny package and VOSviewer for data processing and visualisation, focusing on the integration of seaweed for heavy metal removal. The analysis is based on 369 documents retrieved from the Web of Science (WoS) database from 2014 to 2024. It identifies four major research clusters, highlighting key thematic trends and knowledge gaps. While biosorption remains a core research area, studies on biosorbent enhancement, large-scale implementation, and real-world wastewater treatment are underdeveloped. Thematic mapping reveals limited disruptive innovations, particularly in reactor design optimization, continuous processing systems, and biosorbent regeneration technologies. These limitations constrain scalability and integration into existing industrial wastewater treatment infrastructures. The international co-authorship rate of 34.15% underscores global interest, yet low single-author output (eight documents) indicates reliance on collaborative research. The mean citation rate of 39.85 per document indicates the increasing academic significance of biosorption; nonetheless, the absence of dominant themes implies a gradual shift towards industrial implementation. This study systematically evaluates research gaps and outlines future directions to enhance scalability and industrial viability of biosorption. The insights serve as a roadmap for researchers and policymakers, guiding efforts toward innovative and sustainable wastewater treatment solutions. Uniquely, this work integrates bibliometric analysis and thematic evaluation to propose strategic future directions essential for advancing seaweed-based biosorption towards practical industrial applications.

This study examines the seasonal variations of physicochemical characteristics, microbial load, and antibiotic residue in the Gomti River and associated Bharwara Sewage Treatment Plant (STP), India. Water sample were collected during pre-monsoon, monsoon, and post-monsoon seasons to assess spatial and temporal variations. Significant fluctuations were recorded in parameters such as pH, electrical conductivity (EC), salinity, total dissolved solids (TDS), chemical oxygen demand (COD), nutrients and heavy metals. Among these COD levels at both inlet (204.86 ± 49.34—210.77 ± 24.15 mg/l) and outlet (45.92 ± 13.30—139.63 ± 16.46 mg/l) exceeded the permissible limit prescribed by the Central Pollution Control Board (CPCB, 2021) across all seasons, indicating incomplete efficiency. Bacteriological analysis revealed high contamination with total coliforms, fecal coliforms, and thermos-tolerant E. coli, with total coliforms counts in the river ranging from 366 × 10¹ to 540 × 10¹ CFU/100/ml. The lowest bacterial counts during monsoon were attribute to rainfall-induced dilution. Heavy metals (Fe, Pb, Zn, and Cu) showed seasonal variations, with Fe exceeding Bureau of Indian Standards (Bureau of Indian Standards. (2012). IS 10500: Drinking Water Specification (2nd Revision)) standards in river water. Furthermore, ciprofloxacin residues (0.01–0.49 µg/l) were detected in both STP and river samples, posing potential risks of antibiotic resistance proliferation. The finding highlights the critical influence of seasonal variation on water quality and underscores the urgent need for improved wastewater management, antibiotic monitoring, and sustainable river pollution mitigation strategies.

Understanding how hydroclimatic (HC) and land use and land cover (LULC) variabilities affect surface water quality is very important for effective water resources management. In this study, seven water quality parameters were analyzed in four watersheds in the city of Fortaleza, the Brazilian capital with the highest population density: biochemical oxygen demand (BOD), chlorophyll-a (Chl-a), dissolved oxygen (DO), total coliforms (TC), total nitrogen (TN), total phosphorus (TP), and total suspended solids (TSS). Data were grouped into two periods: the wet period (January to June) and the dry period (July to December). The results showed that intra-annual variability of precipitation and land use/cover had a considerable impact on water quality. The values of Chl-a and BOD were higher during the dry period, while all other parameters tended to show higher concentration during the wet period. According to the results, dilution was the primary factor influencing BOD and chlorophyll-a concentrations, whereas surface runoff played a predominant role in shaping the dynamics of the other water quality parameters.TN was the most responsive parameter to seasonal variations, with higher values in the wet season, possibly due to nutrient transport during rainfall. The degradation of water quality was strongly associated with urban and agricultural land uses, which contribute both point and diffuse sources of pollution. These areas often release excessive amounts of nutrients, organic matter, and sediments into water bodies, mainly through wastewater discharges and stormwater runoff.

Safe management of municipal solid waste incineration (MSWI) ash is essential to avoid detrimental effects of urbanization on the environment and human health. MSWI ash can potentially be used for carbon fixation by mineral replacement. Leaching of MSWI ash was conducted at various pH (7, 9, and 11) conditions and in the presence of additional carbonate ions (0–500 mmol/L). The concentrations of heavy metals in the resulting leachates were negligibly small (< 0.1 mmol/L), even in the presence of added carbonate ions, due to the higher stabilities of their oxide, sulfate, and carbonate species. Ca and Mg, which were significantly leached, were efficiently immobilized at higher pH or by adding carbonate ions; however, an excess of carbonate ions stimulated the release of B and F, increasing their leachate concentrations by factors of 2 to 5. X-ray diffraction and X-ray photoelectron spectroscopy analyses found that B- or F-bearing Ca/Mg minerals in the ash, such as calcium fluorite and layered double hydroxides, were converted to Ca/Mg carbonates. Thermodynamic calculations with geochemical modeling confirmed the mechanism of trace element release. The solubility of B- or F-bearing minerals was determined to be the dominant factor in preventing the leaching of these elements. The leaching potential of Ca/Mg is an essential factor in the carbon fixation capacity of MSWI ash; however, addition of excess carbonate ions induces conversion of the carbonate minerals, resulting in the release B and/or F.

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Highlights

• Trace elements in MSW incineration ash leachate is mobilized by carbonate ions.

• Carbonate ions convert Ca/Mg minerals into Ca/Mg carbonates, releasing adsorbed B and F.

• Ca leaching potential is a factor for carbon fixation without releasing B and F.

The widespread use of aluminum-based coagulants in ecological restoration projects has raised increasing concerns regarding the potential ecological impacts of residual aluminum (Al) in aquatic ecosystems. Epiphytic biofilms on submerged plants play a vital role in regulating nutrient cycling and energy flow in aquatic environments. However, the effects of Al on the biological and abiotic components of epiphytic biofilms on submerged macrophyte leaves remain poorly understood. In this study, we investigated the Al content in epiphytic biofilms on Vallisneria natans and its relationships with nitrogen, phosphorus and bacterial composition in Hangzhou West Lake, China. This location was selected due to the potential for residual Al into the lake from the daily pretreatment of the Qiantang River water diversion project—a water quality improvement project. Our results showed that Al contents in epiphytic biofilms decreased with increasing distance from the inlet and were positively correlated with total phosphorus, Chlorophyll-a and ash-free dry mass (P < 0.05), but showed no significant correlation with total nitrogen. Al accumulation enhanced Chl-a levels in biofilms by increasing the inorganic phosphorus content. Furthermore, Al content was positively correlated with the abundance of Cyanobacteria and negatively correlated with the abundance of Proteobacteria. Al also showed a significant negative correlation with key denitrifying bacteria, such as Vogesella and Phreatobacter, suggesting that elevated Al levels might affect the nitrogen cycling function in epiphytic biofilms. These findings provide important reference data for for ecological risk assessment and inform management strategies for aquatic systems undergoing restoration or exposed to aluminum-based treatments.

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Abandoned agricultural lands carry a legacy of soils contaminated with heavy metals from previous land use practices. Phytoremediation using fast-growing trees is widely used method for ecosystem restoration by accumulating heavy metals in aboveground biomass. In Northern Europe, where 1.8 to 2.6 million hectares of abandoned agricultural land can be afforested, the knowledge of fast-growing tree species' phytoremediation capacity is still poorly studied. This study examines the phytoremediation capacity after 20 years of afforestation of former agricultural lands with hybrid aspen plantations in hemiboreal Estonia, with a particular focus on the effects of different forest site type (Aegopodium, Dryopteris, Hepatica, and Oxalis) on heavy metal concentrations in topsoil and on bark and wood bioaccumulation factors. Soil, wood, and bark samples were collected from 24 sample plots to assess the allocation and accumulation of heavy metals in soil and biomass. The concentration of heavy metals in soil varied by site type, with waterlogged (Dryopteris) sites showing significantly higher levels of Cu, Fe, Ni, and Zn, whereas Cd and Mn were more concentrated in alkaline and dry (Hepatica) sites. The concentration of heavy metals in wood varied with tree size and age; smaller trees had significantly lower Cd, Cu, Fe, and Zn levels, while wood formed in the first decade of stand development showed higher concentrations of Cd, Cu, Mn, and Zn. Soil physical and chemical characteristics showed strong correlations with heavy metal bioaccumulation factors, particularly in bark. Soil pH negatively affected Mn bioaccumulation in all tree parts and Ni, Zn, and Cd in specific tissues, while soil P and available water content positively influenced metal uptake of trees. We found that the phytoremediation capacity of hybrid aspen plantations on former agricultural lands is controlled by soil properties and depends on tree size and age.