Evaluating petroleum contamination risk and implementing remedial measures in agricultural soil rely on indicators such as soil metal(loid)s and microbiome alterations. However, the response of these indicators to petroleum contamination remains under-investigated. The present study investigated the soil physicochemical features, metal(loid)s, microbial communities and networks, and phospholipid fatty acids (PLFAs) community structures in soil samples collected from long-(LC) and short-term (SC) petroleum-contaminated oil fields. The results showed that petroleum contamination increased the levels of soil total petroleum hydrocarbon, carbon, nitrogen, sulfur, phosphorus, calcium, copper, manganese, lead, and zinc, and decreased soil pH, microbial biomass, bacterial and fungal diversity. Petroleum led to a rise in the abundances of soil Proteobacteria, Ascomycota, Oleibacter, and Fusarium. Network analyses showed that the number of network links (Control vs. SC, LC = 1181 vs. 700, 1021), nodes (Control vs. SC, LC = 90 vs. 71, 83) and average degree (Control vs. SC, LC = 26.244 vs. 19.718, 24.602) recovered as the duration of contamination increased. Petroleum contamination also reduced the concentration of soil PLFAs, especially bacterial. These results demonstrate that brief exposure to high levels of petroleum contamination alters the physicochemical characteristics of the soil as well as the composition of soil metal(loid)s and microorganisms, leading to a less diverse soil microbial network that is more susceptible to damage. Future research should focus on the culturable microbiome of soil under petroleum contamination to provide a theoretical basis for further remediation. (c) 2025 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.
The intrusion of petroleum into soil ecosystems causes severe environmental damage. A synergistic plant-microbe-electrochemical soil remediation technology offers a strategic and eco-friendly solution to address this issue. However, the significant mass transfer resistance in soil poses a major limitation for long-distance site remediation. This research introduces a novel technique that leverages water circulation driven by plant transpiration to facilitate the long-distance migration, adsorption, and electrochemical degradation of hydrocarbons. Experimental results demonstrate that the incorporation of Iris tectorum, polyurethane sponge (as an electrode support matrix), and water-retaining agents significantly enhanced soil water circulation, enabling the migration of soluble organic carbon over distances of up to 60 cm. Additionally, the application of a weak voltage (0.7 V) to the electrode further improved total organic carbon (TOC) removal, achieving a reduction of 193 +/- 71 mg/L. After 42 days of remediation, hydrological circulation accelerated the degradation of n-alkanes and aromatics, with removal efficiencies reaching 57 % and 44 %, respectively, within the 20-60 cm range in the microbial electrochemical cell (MEC) group. The functional microbiota, enriched with electroactive microorganisms, was effectively cultivated on the anode, with the total abundance of potential hydrocarbon-degrading bacteria increasing by 42 % compared to the control. Furthermore, a scalable configuration has been proposed, offering a novel perspective for multidimensional ecological soil remediation strategies.
Chromium is a heavy metal used in tanneries, leather industries, electroplating, and metallurgical operations, but improper disposal of waste from these industries leads to environmental contamination. Chromium exists primarily in trivalent and hexavalent forms, with hexavalent chromium (Cr (VI)) being highly toxic. Cr (VI) is carcinogenic, damages fish gills, and negatively impacts crops. Considering these negative impacts of Cr (VI), several physical, chemical, and biological remediation methods have been implemented at contaminated sites, but in most instances, these methods could be uneconomical, highly labor-intensive, and not sustainable. Therefore, a crucial goal is to implement an effective and sustainable remediation technique with consideration of actual site conditions. The aim is to develop a sustainable remediation strategy for a hexavalent chromiumcontaminated site in Ranipet, Tamil Nadu. The comprehensive risk assessment for the site has depicted hazard quotients greater than 1 for both onsite and offsite conditions, indicating the necessity of remediation. To address this, it is suggested to build permeable reactive filters (PRFs) packed with scrap iron filings to reduce Cr (VI) to Cr (III), and succeeding filters with locally produced waste coconut shell biochar to aid in adsorption. The use of waste here aims to eliminate the need to procure any commercially available materials for remediation, completely cutting down the environmental impact of raw material extraction or processing. A continuous chambered set-up packed with contaminated soil and PRFs with biochar and iron filings aided in the decrease of the peak concentration of Cr (VI) by 61 % as compared to a set-up without intervention. Moreover, the outlet concentration after 7 days reduced to 0.08 mg/L, which was 97.6 % less than that in the set-up without intervention.
Cadmium (Cd) is one of the most harmful heavy metals in the environment, negatively impacting plant growth and development. However, phytoremediation which is an environmentally friendly and cost-effective technique can be used to treat Cd contaminated environments. It effectively removes Cd from polluted soil and water through processes, such as phytoextraction, phytostabilization, phytostimulation, phytofiltration, and phytotransformation. Numerous research has shown evidences that biological, physical, chemical, agronomic, and genetic methods are being utilized to improve phytoremediation. A special group of plants known as hyperaccumulator plants further enhance Cd removal, turning polluted areas into productive land. These plants accumulate Cd in root cell vacuoles and aerial parts. Despite the morphological and genetic variations, different plant species remediate Cd at different rates using either one or multiple mechanisms. To improve the effectiveness of phytoremediation, it is essential to thoroughly understand the mechanisms that control the accumulation and persistence of Cd in plants, including absorption, translocation, and elimination processes. However, what missing in understanding is in depth of idea on how the limitations of phytoremediation can be overcome. The limitations of phytoremediation can be addressed through various strategies, including natural and chemical amendments, genetic engineering, and natural microbial stimulation, broadly categorized into soil amelioration and plant capacity enhancement approaches. This review presents a concise overview of the latest research on various plants utilized in Cd phytoremediation and the different methods employed to enhance this process. Moreover, this review also underscores the creditability of phytoremediation technique to remediate Cd pollution as it offers a promising approach for eliminating Cd from contaminated sites and restoring their productivity. Additionally, we recommend directing future research toward enhancing the biochemical capabilities of plants for remediation purposes, elucidating the molecular mechanisms underlying the damage caused by Cd in plants, and understanding the fundamental principles regulating the enrichment of Cd in plants.
As a green remediation technology for complete remediation of contaminated soil, the combination of easily recoverable adsorbents and washing still faces challenges such as low remediation efficiency and unclear remediation mechanisms. Hence, the bis Schiff base functional group comprising sulfhydryl groups was loaded into the UiO-66 calcium alginate spheres (UiO-66-AMB-ACPs) to obtain efficient selective adsorption. The results of response surface optimization showed that the maximum removal of Pb and Cd from soil reached 69.73% and 82.63% by the combination of UiO-66-AMB-ACPs with acetic acid, of which about 95.55% and 60.31% were attributed to the adsorption. Factor interaction analysis demonstrated that solid-liquid ratio combined with either adsorbent dosage or acetic acid concentration significantly affected Cd adsorption rates. In the above system, Schiff bases,-SH, and carboxylic acids in UiO-66-AMB-ACPs compete for the Pb and Cd captured by acetic acid through chelation, ion exchange, and complexation, which assisted in maintaining the high desorption rate to further enhance the resolution process of acid-soluble and reduced Pb and Cd. The release of free acetic acid will again participate in the resolution of heavy metals, thus constituting an internal cycle of acetic acid. UiO-66-AMB-ACPs were maintained in a stable state during each of the 18 cycles. The remediated soil retained most of the plant nutrients, while the mobility of residual heavy metals was greatly inhibited. This technique showed promise for the total removal and recovery of Pb and Cd from contaminated soils with low damage and short time while immobilizing the residual heavy metals.
Microplastics (MPs) and nanoplastics (NPs), formed through the degradation of larger plastic materials, are emerging pollutants of significant concern. While their impact on aquatic ecosystems is well documented, their effects on terrestrial, especially farm animals remain underexplored. This review assesses the potential threats of MPs and NPs to Bangladesh's livestock sector by analyzing the results of experimental models and environmental studies. In Bangladesh, MPs and NPs have been detected in agricultural soils, air, water bodies, and aquatic organisms, indicating possible entry into animal systems through contaminated feed, water, and inhalation. Once internalized, these particles may trigger oxidative stress, inflammation, and tissue damage, impairing vital biological systems. Documented health consequences include reduced fertility, hematotoxicity, gut microbiota imbalance, gut-brain axis disruption, skeletal disorders, and metabolic dysfunction. Additionally, MPs and NPs can induce genomic changes, including altered gene expression and DNA hypomethylation, intensifying physiological damage and reducing productivity. Therefore, managing plastic contamination is vital in protecting animal health, ensuring food safety, and preserving human well-being around the globe, especially in vulnerable regions like Bangladesh. Given the critical role of livestock and poultry in ensuring food security and public health, the findings highlight an urgent need for comprehensive research and mitigation strategies.
Phytoremediation assisted by endophytic bacteria is a promising strategy to enhance the remediation efficiency of heavy metals in contaminated soil. In this study, the capacity and role of the endophytic Bacillus sp. D2, previously isolated from Commelina communis growing near a copper (Cu) mine, in assisting the phytoremediation were evaluated. Results showed that inoculation of Bacillus sp. D2 significantly enhanced the biomass production of C. communis by 131.06% under high level of Cu stress. Additionally, the oxidative damages caused by Cu toxicity in C. communis tissues were alleviated as evidenced by significant reductions in malondialdehyde (MDA), superoxide anion (O2 center dot-) and proline content following Bacillus sp. D2 inoculation. Meanwhile, the activities of antioxidant enzymes in plant leaves presented upward trends after Bacillus sp. D2 inoculation. Notably, Bacillus sp. D2 inoculation significantly decreased Cu uptake and translocation by C. communis, while enhancing the Cu stabilization in contaminated soils. Furthermore, soil enzyme activities (acid phosphatase, catalase, and urease), as well as the richness of soil bacterial communities in Cu-contaminated soil increased following Bacillus sp. D2 inoculation. Importantly, the inoculation specifically augmented the relative abundance of key bacterial taxa (including Pseudomonas and Sphingomonadaceae) in the rhizosphere soil, which was positively correlated with soil nutrients cycling and plant growth. Our findings suggest that the endophytic strain Bacillus sp. D2 can strengthen the phytostabilization efficiency of Cu by C. communis through its beneficial effects on plant physio-biochemistry, soil quality and bacterial microecology, which provides a basis for the relative application to Cu-contaminated soils.
Acid contamination has a notable influence on the geotechnical properties of soil and this influence is strongly dependent on contamination concentration (pH) and contamination duration. To fully investigate the effect of acid contamination on the microscopic and strength properties of natural clay, a series of micro- and macrolaboratory tests were performed in this study, and the mechanism of this effect was comprehensively revealed. Microscopic analysis indicates that acid contamination could lead to some mineral transformations in clay, such as illite-smectite transforming into chlorite and illite transforming into kaolinite. Besides, more large pores and a looser structure can be observed in the clay due to the erosional effects of acid contamination, which could effectively weaken the strength properties of natural clay. The experimental results also indicated that, when subjected to acid contamination, the lower contamination pH could lead to a notable decrease in clay's shear strength, while the clay's shear strength increased initially and then decreased as contamination duration increased. In addition, gray correlation analysis results demonstrated that calcite has a significant effect on cohesion, while also indicating a strong correlation between illite and the internal friction angle.
Hazardous waste from metal processing industries increases heavy metal contamination in ecosystems, threatening environmental health and regional sustainability. This study suggests a resilient and human-centered environmental monitoring approach that incorporates machine learning and decision analytics to address these challenges in line with Industry 5.0's goals. By utilising a PRINCIPAL COMPONENT REGRESSION (PCR)-based predictive model, the approach addresses variability in environmental data, predicting levels of heavy metals like lead, zinc, nickel, arsenic, and cadmium, frequently beyond regulatory thresholds. The suggested PCR-based model outperforms conventional models by lowering mean absolute error (MAE) to 2.9339, mean absolute percentage error (MAPE) to 0.0358, and nearly the same mean square error (MSE). This study introduces a more interpretable and computationally efficient alternative to existing predictive models by introducing a novel integration of PCR with machine learning for environmental monitoring. By predicting and optimising environmental outcomes, validation against test datasets confirmed its ability to optimise impurity control. After process adjustments, the average concentrations of lead, nickel, and cadmium were reduced from 13.23 to 11.26 mg/L, 2.83 to 2.70 mg/L, and 2.15 to 1.88 mg/L, respectively. This research supports sustainability, resilience, and decisionmaking aligned with Industry 5.0, offering scalable solutions and insights for global industries.HighlightsChemical plants' environmental risk is evaluated using a machine learning algorithmFor better monitoring, the PCR method forecasts process variables and interactionsIt identifies the key factors that affect the environmental risks in soil and waterAs a result, the local ecosystem's levels of toxic metals have notably decreasedInsights for managing environmental risks aligned with Industry 5.0 principles
Radioactive cesium was released into the environment from the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company, which was damaged by the Great East Japan Earthquake. The shiitake industry suffered various damages as a result. One type of damage is contamination by radioactive cesium in the cultivation environment, known as 'additional contamination'. Additional contamination is assumed to be caused by the transfer of radioactive cesium from the soil to the fruiting bodies via the bed-logs. We conducted a 15-month bed-log cultivation in a glasshouse on soil contaminated with radioactive cesium to verify the transfer of radioactive cesium from the soil to the fruiting body. The transfer was verified mainly using stable cesium, but no transfer of radioactive cesium from soil to the fruiting body was observed. This result indicates that additional contamination is caused by other factors.