90Sr is a representative anthropogenic radionuclide, widely released into the environment through atmospheric nuclear tests, nuclear accidents, and routine operations of nuclear facilities, resulting in long-term residual contamination in soils worldwide. Its long half-life, high mobility, and chemical similarity to calcium make it easy to enter the food chain through the soil-plant system, thereby posing a persistent threat to ecosystems and human health. Conventional physical and chemical remediation approaches are often costly, ecologically disruptive, and inefficient for large-scale applications, highlighting an urgent need for sustainable, in situ strategies. Moreover, existing knowledge on 90Sr behavior has largely been generated from isolated studies, lacking an integrated framework to guide remediation efforts. This review summarizes the migration mechanisms of 90Sr in the soil-plant system and the main factors influencing its transport and accumulation. In soil, the migration of 90Sr is jointly controlled by soil texture and mineral composition, competing cations, organic matter, soil pH, and moisture, with cation exchange acting as the main immobilization mechanism. Plant uptake and accumulation of 90Sr show distinct inter- and intra-species differences, and the distribution generally follows the pattern of vegetative organs > reproductive organs. This process is regulated by root activity, transpiration, and competition with Ca2+ transport channels. Agronomic practices such as liming, deep plowing, and balanced fertilization can effectively reduce the phytoavailability of 90Sr by promoting ion competition and modifying the rhizosphere environment. Meanwhile, phytoremediation offers a promising green approach for the remediation of contaminated soils. Overall, this review provides a theoretical basis and scientific reference for the risk management and bioremediation of 90Sr in soil-plant systems.
Persistent organic pollutants (POPs) pose significant ecological and human health risks due to their persistence, bioaccumulation, toxicity, and global distribution. Conventional remediation methods are often inadequate for achieving complete mineralization, demonstrating the need for advanced and substantial approaches. Recent studies have explored photocatalytic and biotechnological methods as promising alternatives; however, critical gaps remain regarding the toxicity of transformation products, implications for antimicrobial resistance (AMR), and the scalability of hybrid systems. This review assesses photocatalytic and biotechnological strategies for POP remediation, focusing on their mechanisms, performance, and environmental impacts. Photocatalysis enables the rapid degradation of recalcitrant compounds with reported removal efficiencies often exceeding 70%-95% under optimized conditions for pollutants. In contrast, biotechnological approaches facilitate selective and complete mineralization through microbial and enzymatic processes but are influenced by environmental conditions and pollutant bioavailability. Hybrid photocatalytic-biological systems demonstrate enhanced efficiency by coupling oxidative pretreatment with biodegradation, although their performance may vary depending on system integration and operational conditions. This review focuses on the formation and fate of intermediate by-products, their potential toxicity, and the influence of remediation processes on microbial communities and AMR dynamics. Unlike previous studies, this work integrates material science, environmental toxicology, and microbial ecology while emphasizing emerging tools such as omics technologies, synthetic biology, and digital optimization to advance risk-informed and sustainable remediation strategies.
Early identification and remediation of professionalism concerns in medical students remains a critical challenge in medical education, particularly when professionalism lapses occur alongside clinical skill deficits. This article describes a structured approach to remediating combined clinical and professionalism deficiencies in a first-year medical student through independent expert preceptorship, workplace-based assessments, and guided reflective practice. Drawing from established remediation frameworks and our program experience, the remediation model includes components of clear professionalism criteria, structured reflection with attention to self-assessment capacity, and serial evaluation to identify patterns of behavior over time. The framework also highlights key implementation considerations, including preceptor preparation, faculty development needs, and the use of practical tools such as reflection prompts and behavior-pattern classifications to support consistent remediation decisions. This approach emphasizes early intervention, transparent expectations, targeted feedback, and longitudinal assessment to support learner growth while maintaining educational standards and professional accountability.
The co-contamination of manganese ions (Mn2+) and ammonia nitrogen (NH4+) caused by the stockpiling of manganese residue poses a serious threat to the ecological environment. In this study, a series of the composite was prepared from red mud, bentonite, and corn straw via oxygen-limited pyrolysis. The effects of pyrolysis temperature and raw material ratio on the material properties were investigated, and the synergistic remediation performance of the composites for Mn2+ and NH4+ in manganese residue-contaminated soil was evaluated through a 180-day soil column experiment. The results showed that the composite prepared with a raw material ratio of 1:1:1 at a pyrolysis temperature of 700 °C exhibited the largest specific surface area and the most developed pore structure, achieving a Mn2+ removal rate of 92.72% ± 0.85% in aqueous solution. In the soil column experiment, the material prepared at 700 °C gave the highest immobilization rate for soil Mn2+ (96.22% ± 0.5%), whereas the combined addition of materials prepared at 700 °C and 500 °C achieved the best removal efficiency for NH4+ (99.33% ± 0.23%). Mechanistic studies revealed that the stabilization of Mn2+ is primarily attributable to alkaline precipitation and mineral lattice solid solution induced by the composite, leading to the formation of stable spinel phases (e.g., (Fe,Mn)3O4) and insoluble manganese phosphate-carbonate salts. The removal of NH4+ is proposed to proceed via adsorptive enrichment by the porous structure and Fe0-mediated Fenton-like catalytic oxidation, ultimately converting NH4+ to N2 gas. The 180-day monitoring results demonstrated that the remediation effect continuously increased over time, indicating good long-term stability of the composite. This study provides an efficient, low-cost functional material derived from solid waste for the remediation of manganese residue-contaminated soil and offers a theoretical basis for the synergistic resource utilization of multiple solid wastes.
Glyphosate (GLY), one of the most extensively applied broad-spectrum herbicides worldwide, frequently contaminates soil and aquatic ecosystems, posing serious threats to human health, non-target organisms, soil microbial communities, and environmental sustainability. In the present study, phytoremediation using Medicago sativa (MS) was evaluated for the removal of GLY from contaminated soil under greenhouse conditions, with remediation efficiency enhanced through inoculation with two bacterial bioagents, Bacillus sp. h10 (BS) and Pseudomonas aeruginosa KZFS4 (PA). Biochemical parameters, including superoxide dismutase (SOD), catalase (CAT), hydrogen peroxide (H2O2), and malondialdehyde (MDA), together with detoxification-related gene expression, were investigated in the roots and leaves of MS exposed to GLY stress. The combined application of MS with BS + PA, followed by MS + PA and MS + BS, significantly decreased GLY residues in soil and increased GLY accumulation in plant roots and leaves after 1, 3, 7, and 10 days compared with MS treatment alone. In vitro batch equilibrium experiments demonstrated that BS and PA desorbed 33.63 and 40.56 µg g-1 of GLY, respectively, thereby enhancing its removal from soil. The persistence of GLY was highest in contaminated soil without treatment, exhibiting a half-life (t1/2) of 52.66 days, whereas the shortest half-life (6.69 days) was recorded in soil treated with MS combined with BS and PA relative to sterilized contaminated soil. Furthermore, inoculation with BS and PA markedly increased SOD and CAT activities in MS tissues, while significantly reducing H2O2 and MDA accumulation, indicating alleviation of oxidative stress. GLY exposure also triggered substantial upregulation of detoxification-associated genes, including cytochrome P450, glutathione S-transferases (GST), glycosyltransferases (GTs), and ABC transporters in MS. These findings demonstrate that the integration of BS and PA with phytoremediation effectively accelerates GLY dissipation and reduces pesticide-associated toxicity in contaminated soils and plants.
Polycyclic aromatic hydrocarbons (PAHs) are persistent and toxic pollutants that accumulate in urban soils, reducing microbial diversity and compromising ecosystem functioning. Developing effective bioremediation strategies requires identifying native degraders and understanding their ecological dynamics under pollutant pressure. Here, we investigated fungal and bacterial communities from PAH-contaminated soil subjected to three consecutive enrichment steps using phenanthrene, fluoranthene, benzo(a)pyrene, benzo(g,h,i)perylene, and their mixture as the sole carbon sources. High-throughput sequencing of ITS2 and V3-V4 amplicons revealed a decline in alpha diversity and a strong restructuring of both communities during the enrichment. Distance-based redundancy analysis showed that contaminant type and enrichment progression jointly shaped community composition, selecting for stress-tolerant taxa. Culturomics yielded 102 fungal isolates, representing 19 taxa, predominantly within Ascomycota. The most represented taxa were Galactomyces pseudocandidus (19 strains), Fusarium oxysporum (five), Stilbella aciculosa and Exophiala attenuata (four each) and Fusarium solani (three). Approximately one-third of isolates harbored associated bacteria, mainly Stenotrophomonas, Bosea and Chitinophaga species. Functional assays identified biosurfactant-producing strains, while microplate screening highlighted Fusarium solani, Galactomyces pseudocandidus and Trametes versicolor as capable of growing under PAH-selective conditions. Overall, our results demonstrate that PAH-contaminated soils host fungal taxa able to persist under pollutant pressure together with recurrent fungi-associated bacteria of potential ecological relevance for bioremediation.
Heavy metal pollution has become a critical concern in agricultural ecosystems driven by a complex matrix of industrial practices, high-input fertilizers, metal-based agrochemicals, and wastewater irrigation. While the previous literature typically highlights general physiological symptoms of heavy metal stress, this review provides a novel, comprehensive framework that bridges three independent pillars: specific industrial applications dictating elemental pathway, localizes active root-zone transport kinetics, and an engineering-based evaluation of emerging remediation strategies. We systematically synthesized literature from 2000 to 2026 across major databases (WoS, PubMed and Google Scholar), applying strict inclusion criteria based on data validation, experimental reproducibility, and mechanistic depth. We examine the geochemical behavior, cellular toxicity, and plant resilience mechanics of seven priority elements like cadmium, lead, arsenic, aluminum, mercury, chromium and molybdenum. Rather than merely reiterating superficial visual damage like chlorosis or stunted growth, we focus on physiological and molecular root causes of phytotoxicity, including the structural hijacking of essential nutrient networks, intracellular reduction cascades and organelle-specific oxidative disruption. This review also discussed the discovery of specialized, energy-dependent eukaryotic transport mechanisms like ABC transporters and a comparative operational blueprint evaluating physical-chemical conventional remediation techniques against advanced in situ and ex situ biotechnological approaches, including biochar assistance, microbial engineering, rhizosphere synergies, and engineered nanomaterials. By systematically linking industrial source dynamics with cellular toxicological mechanisms and field-scale engineering feasibility, this review establishes an actionable roadmap for future genetic, agronomic, and management interventions aimed at securing global food.
New approaches are needed to address soil contamination by total petroleum hydrocarbons (TPHs), which poses persistent environmental risks. This study investigated the integration of electrokinetic (EK) remediation with cork-based permeable reactive barriers (PRBs) assisted by surfactants as a strategy for treating diesel-contaminated soils. The effects of surfactant type, soil texture (sand and sandy loam), and electric field strength (1.0 and 1.8 V cm-1) on diesel mobilization and retention in cork barriers were evaluated. Two surfactants with distinct ionic properties, sodium dodecyl sulfate (SDS, anionic) and Triton X-100 (non-ionic), were selected as representative models. The regranulated cork can sorb TPHs, with predicted maximum sorption capacities of (12 ± 4)×10-6 and (8 ± 0.5)×10-6 mol g-1 for SDS and Triton systems, respectively. Electrokinetic trials revealed that sand-based systems exhibited negligible retention of TPHs (<1%) due to short residence times and low cation exchange capacity. While sandy loam systems achieved up to 22% retention in the cork barrier in Triton-assisted setups, which exhibited substantially higher transport and PRB retention efficiency of TPHs than SDS, likely due to better electroosmotic compatibility and neutral micelle behaviour that favour retention in the hydrophobic cork matrix. In the SDS systems, the reduced contaminant transport observed may have limited the PRB interception. The effect of the electric field strength (1.0-1.8 V cm-1) was not significant. These findings highlight cork's potential as a natural, renewable, sustainable and low-cost medium for cork-based PRBs. The study provides useful insights into combining cork-based PRBs with EK remediation surfactant-assisted, which is a promising approach for capturing hydrophobic pollutants in situ.
Microbial fuel cells (MFCs) are emerging as biomimetic bioelectrochemical systems that emulate naturally occurring microbial electron-transfer pathways for stimulus bioenergy generation and wastewater remediation. In this study, food-vegetable leachate (FVL) and sugarcane bagasse-derived biol were evaluated in combination with carbon fiber (CF) and biochar-modified carbon fiber (BCF) electrodes used as membrane components in MFCs. Four configurations, in duplicate, were constructed by coupling two substrates (biol or FVL) with two membrane types (CF and BCF). All systems exhibited progressive anodic acidification and up to a 55% increase in electrical conductivity. The highest voltage output was achieved in MFC-BL-2 (404.59 mV), followed by MFC-FL-1, driven by synergistic interactions between the substrate and biochar-enhanced conductive networks. MFC-FL-1 also demonstrated superior contaminant removal performance, achieving 60% COD reduction, 36% BOD reduction, and 50% NH4+-N removal. SEM-EDS analysis confirmed that biochar-modified electrodes developed a porous structure and substantially enhanced microbial adhesion. FVL-fed systems formed dispersed electroactive biofilms that facilitated electron transfer, whereas biol-fed systems developed compact biofilms that constrained electron flux. By integrating waste-derived lignocellulosic materials with electroactive microbial consortia, this work advances a biomimetic circular bioengineering platform for sustainable bioelectrochemical recovery and wastewater remediation.
The extensive use of plastics in everyday life has exerted a significant influence on the environment, with the release of micro- and nanoplastics posing even greater ecological threats. Plastic contamination, particularly in these smaller forms, has emerged as a pressing environmental concern due to its persistence, bioaccumulation, and potential hazards. Traditional treatment systems are generally ineffective at removing such micro- and nano-scale complex pollutants. Recently, micro- and nanofiber-based materials have emerged as promising candidates due to their large surface area, porous structure, and adjustable functionality, enabling efficient adsorption, filtration, and photocatalytic degradation. The term micro/nanofibers in this study encompasses both electrospun nanofibrous membranes and nanofiber-based functional layers or additives incorporated into pre-existing membrane structures for performance enhancement. The incorporation of photocatalysts enables these materials to promote photocatalytic oxidation, degrading plastics into smaller, less toxic compounds. This paper outlines recent progress in developing micro- and nanofiber systems for environmental remediation, highlighting their design approaches, removal mechanisms, and multifunctional capabilities. Ultimately, the discussion explores emerging directions, existing limitations, and future opportunities, highlighting how these advanced materials can contribute to sustainable and efficient pollution control strategies.
The present study explores the impact of UV-B radiation on biochemical traits and phenolic profile of in vitro cultures (IC) and micropropagated plants (MP) of Lavandula viridis L'Hér and Thymus lotocephalus G. López and R. Morales. Two UV-B treatments were applied: a single 4 h exposure (UV-B 1) and repeated exposure over four consecutive days (UV-B 4). Additionally, the potential of phenolic-rich extracts loaded into alginate-based hydrogels for dye removal was also evaluated. UV-B exposure triggered oxidative stress in both species, particularly in MP, increasing hydrogen peroxide levels and lipid peroxidation, and affecting chlorophyll and carotenoid content. Both species responded by accumulating soluble sugars and phenolic compounds as a defense mechanism. Rosmarinic acid, the predominant phenolic compound, increased significantly under UV-B radiation in IC and MP. IC showed higher concentrations after UV-B 1 exposure, with L. viridis reaching 50.1 mg/g and T. lotocephalus 32.3 mg/g, increases of 16% and 41%, respectively, over the control. Polyphenol-loaded hydrogels showed high methylene blue adsorption efficiency, highlighting their potential as eco-friendly materials for wastewater treatment and environmental remediation. Optimal adsorption conditions were determined using Box-Behnken design and Response Surface Methodology, demonstrating the applicability of these natural hydrogels as sustainable and efficient materials for dye removal from contaminated wastewater.
Ligninolytic macromycetes are important producers of oxidative enzymes with potential applications in the mycoremediation of synthetic dyes. However, the enzymatic potential of native tropical lignicolous fungi and the optimization of enzyme production for dye degradation remain poorly understood. This study aimed to isolate and characterize native lignicolous fungi, evaluate their ligninolytic enzyme production and dye-degrading [malachite green (MG) and phenol red (PR)] capacity, and optimize enzyme production using response surface methodology. Five fungal isolates were identified as Trametes villosa, Trametes sp., Junghuhnia sp., Pycnoporus sanguineus, and Schizophyllum commune. On PDA, T. villosa exhibited the highest mycelial growth rate (1.16 cm day-1), whereas P. sanguineus showed the highest laccase activity (18.64 U L-1). Under submerged fermentation, P. sanguineus produced the greatest H2O2 (418.9 mg L-1), laccase (398.6 U L-1), and lignin peroxidase (618.3 U L-1) activities; while Junghuhnia sp. exhibited the highest manganese peroxidase (MnP; 32.9 U L-1). Crude enzymatic extracts degraded MG and PR by 94.57% and 47.84%, respectively, within 72 hr. Box-Behnken optimization revealed that high glucose concentrations (30 g L-1) enhanced laccase production in 0.86-fold increase, whereas low yeast extract (1.25 g L-1) favored MnP synthesis in 5.10-fold increase. These findings identify native tropical fungi, particularly P. sanguineus, as promising candidates for enzyme-based wastewater treatment and environmental remediation.
Despite increasing interest in fungal remediation systems for the treatment of persistent contaminants, the mechanisms governing fungal transformation of halogenated organic compounds remain poorly resolved. The aim of this study was to determine whether the transformation of halogenated nitrophenols is driven by isolated extracellular enzymes and cofactor-dependent oxidative activity or instead reflects coordinated system-level fungal metabolism. To address this question, we investigated the transformation of 2-chloro-4-nitrophenol (2C4NP) and 5-fluoro-2-nitrophenol (5F2NP) by ascomycete fungi Caldariomyces fumago (C. fumago) and Curvularia sp. under varying nutrient and cofactor conditions. Whole-culture transformation, crude supernatant activity, purified enzyme assays, intracellular detoxification responses, and genome-resolved functional annotation were integrated to evaluate the relative contributions of extracellular and intracellular processes. Transformation was strongly dependent on fungal species, substrate identity, nutrient availability, and cofactor composition. C. fumago achieved complete transformation of 2C4NP and up to 85.3% transformation of 5F2NP, whereas Curvularia sp. exhibited strict Na3VO4-dependent transformation of 5F2NP. Crude supernatants retained partial transformation capacity, achieving ~40-45% substrate depletion under conditions supporting whole-culture activity. Purified chloroperoxidase and laccase showed negligible independent activity and did not reproduce whole-culture transformation behavior. Lignin peroxidase activity was consistently induced during contaminant exposure and peaked during periods of maximum transformation. Cytochrome P450 inhibition did not prevent transformation. Baseline glutathione S-transferase activity was detected in both fungi, and comparative genome analysis identified conserved intracellular detoxification-associated enzyme alongside divergent extracellular oxidative enzyme repertoires. Together, these findings demonstrate that transformation of halogenated nitrophenols by fungi cannot be explained by isolated extracellular enzymes alone but is consistent with coordinated extracellular and intracellular system-level metabolism. These findings highlight an underexplored role for integrated fungal metabolic systems in bioremediation and provide a mechanistic basis for developing a scalable fungal platform for treatment of persistent halogenated contaminants.
Although microbial remediation is a promising strategy for PAH pollution control, its field application remains a significant challenge. PAH-degrading microbial consortia were enriched from contaminated sites in Nanjing. High-throughput sequencing was applied to analyze the community structure and functional characteristics of bacteria and fungi, and the phenanthrene degradation performance of free consortia and sodium alginate-activated carbon-immobilized composite beads was systematically evaluated. Results showed that the distance from the pollution source was the key factor driving the differentiation of microbial community structure. For bacteria, sites closer to the pollution source showed significantly lower bacterial diversity and richness, while an opposite trend was observed for fungi. Proteobacteria (40-87%) and Ascomycota (51-88%) were the dominant phyla of bacterial and fungal communities, respectively. Despite significant differences in genus-level community composition among samples, the functional gene abundance related to PAHs metabolism was highly similar across all consortia. The immobilized composite beads achieved a significantly higher phenanthrene degradation efficiency (94.70-99.26%) compared with free consortia (65.84-85.78%). The embedding material had a significant effect on degradation performance, while nutrient sources showed no significant impact on the degradation efficiency. This study provides theoretical support for the application of immobilized microbial technology in PAH-contaminated site remediation.
Graphene and its derivatives have attracted sustained research interest as adsorbent materials for environmental applications, driven by their large surface area, chemically tunable surface, and compatibility with a wide range of functional modifications. This review covers recent developments in the use of graphene-based materials for water, air, and soil remediation, focusing primarily on work published over the last five years. A concise overview of graphene, its derivatives, and other carbon nanostructures, such as carbon nanotubes and fullerenes, is also provided. The main graphene derivatives are briefly described (graphene oxide, reduced graphene oxide, graphene nanoribbons, and graphene quantum dots) together with a comparative overview of the principal synthesis methods, from mechanical exfoliation and chemical vapor deposition to liquid-phase exfoliation, oxidation/reduction, and flash Joule heating. The discussion then turns to how surface functionalization and composite formation affect adsorption performance in practice. In water treatment, the results are most developed: functionalized composites have reached adsorption capacities of 484.3 mg g-1 for organic dyes and 157.23 mg g-1 for Cr(VI). Air purification is a smaller but growing area, with plasma-treated graphene aerogels achieving CO2 capture capacities of 3.3 mmol g-1 and retaining performance over 40 cycles. Soil remediation remains the least explored compartment, though arsenic immobilization efficiencies of up to 99.3% have been reported. Remaining challenges around scalability, behavior in real environmental matrices, and long-term ecotoxicological impact are identified and discussed.
The present study evaluated bioaugmented floating treatment wetlands (FTWs) for the effective remediation of textile waste enriched with the azo dyes Synozol Red K3 BS (SR), Synozol Yellow K3 RS, and Synozol Ultra Black DR (SB). Six strains of bacteria (SZ1-SZ6) were isolated, characterized and tested for the ability to decolorize dyes. Of these, the SZ1 strain, Bacillus sp., was observed to have a maximum removal rate of 92% for SR, 89.96% for SY and 54% for SB dyes in shake flask assays. The performance of SZ1 was further optimized under different physicochemical conditions, pH (1, 3, 5, 7, 9, 11, and 13), incubation temperature (30-40°C), incubation days (1, 3, 5, and 7), and inoculum size (1, 2, 3, and 4%). The results indicated that optimum conditions for maximum decolorization were at pH 7, temperature 37°C and 2% inoculum size. SZ1 was then optimized and further introduced in FTWs vegetated with Typha domingensis. Bioaugmented FTWs (T. domingensis + Bacillus sp.) achieved significantly more dye removal up to 95% compared with FTWs with only plants or bacteria. Moreover, growth parameters (root and shoot length) were improved in bioaugmented systems indicating reduced toxicity. The results demonstrated that Bacillus Sp. and T. domingensis were complementary effective in the performance of FTWs to treat the dye-contaminated water, which provided an environmentally friendly FTW-based remediation solution as compared to the conventional one.
Nickel (Ni) toxicity in agricultural soils, stemming from industrial activities, fertiliser use, and sewage sludge, severely disrupts plant growth by inducing oxidative stress. Calcium-based soil amendments have emerged as promising strategies for mitigating heavy metal toxicity; however, their comparative effectiveness and underlying protective mechanisms remain insufficiently understood. This study evaluated the potential of lime and gypsum to mitigate Ni toxicity in maize (Zea mays). A pot experiment was conducted using Ni-contaminated soil amended with lime and gypsum applied at rates of 0.2%, 0.4%, and 0.6% of calcium. The results showed that both amendments effectively reduced Ni bioavailability in the soil, leading to improved maize growth and physiological performance. Among all treatments, the application of gypsum at 0.6% was the most effective, significantly increasing root and shoot biomass, enhancing chlorophyll content, and improving photosynthetic gas exchange parameters. This improvement was linked to the upregulation of antioxidant enzyme activities and increased osmolyte production, which together alleviated oxidative stress. Concurrently, calcium treatments substantially reduced Ni uptake and accumulation in plant tissues. These findings demonstrate that calcium-based amendments, particularly gypsum, serve as a cost-effective strategy for the remediation of Ni-contaminated soils. It was concluded that applying 0.6% gypsum mitigates Ni toxicity in maize by reducing metal bioavailability and uptake while simultaneously enhancing antioxidant defences and photosynthetic efficiency, thereby offering a practical solution for sustaining crop productivity and ensuring food security in heavy metal-polluted environments.
The widespread occurrence of antibiotics in the environment threatens public health and ecosystem safety. This review summarizes the global occurrence of antibiotic contamination across the different environmental media, i.e., water systems, solid wastes, and soils, and provides a comprehensive analysis of physical, chemical, and biological removal methods, including their mechanisms, application advantages and disadvantages. It is deduced that physical methods aid in antibiotic enrichment, which leads to residual accumulation and fails to achieve complete degradation. In comparison, chemical methods are more efficient and rapid, but they are largely limited by high costs and secondary pollution. Biological methods, despite being appealing due to their low costs and environmental friendliness, may generate and spread antibiotic-resistant bacteria. To overcome the disadvantages of these conventional treatment methods, this review emphasizes the significant potential of integrated antibiotic removal systems, such as coupled advanced oxidation processes (AOPs), physical methods combined with AOPs and chemical methods combined with biological methods, which could achieve superior treatment performance. Future research should focus on optimizing and simplifying coupled systems and developing innovative treatment methods to enhance removal efficiency, reduce operational costs, and minimize secondary toxicity, thereby enabling effective antibiotic pollution remediation. This review summarizes the global state of antibiotic residues and stresses the importance of combined treatment methods for enhancing antibiotic degradation and removal, providing the valuable insights for green and efficient antibiotic treatment.
Polymetallic mining severely disrupts farmland soil ecosystems, yet the vertical migration of heavy metals, interlayer pollution disparities between topsoil and deep soil, and quantitative source apportionment of composite pollutants remain poorly understood in mining-agricultural overlapping zones. Two core hypotheses were accordingly proposed: mining-derived heavy metals can migrate downward and accumulate in deep soil layers, and the coupling of geostatistical analysis and receptor modeling enables reliable differentiation between geogenic and anthropogenic pollution sources. To test these hypotheses, 512 topsoil and 148 deep soil samples were collected from the Fenghuang Mining Area for quantification of eight metals and metalloids (including As). Geostatistical approaches, the single pollution index (Pi), and Nemerow comprehensive pollution index (PN) were utilized to characterize spatial heterogeneity and evaluate pollution severity, while a coupled PCA-PMF receptor model was adopted for quantitative source identification; vertical comparisons of element concentrations across soil profiles further validated the robustness of source apportionment outputs. The results revealed extensive heavy metal enrichment in both soil layers, with only topsoil Cd exceeding China's risk screening value for agricultural land. Hg exhibited pronounced spatial variability and prominent anthropogenic fingerprints, and all target metals displayed consistent spatial distribution patterns along vertical soil profiles. Four distinct pollution sources were discriminated: geogenic sources dominating Cu, Zn, Cr, and Ni accumulation, mining-industrial emissions as the major contributor to Hg pollution, mixed industrial-agricultural inputs governing As and Pb enrichment, and traffic activities serving as the primary Cd source. Cd was identified as the priority pollutant threatening local farmland security. Confirmed downward percolation of anthropogenic metals creates persistent latent ecological risks across the study area, where mining and industrial discharges represent the dominant anthropogenic pollution inputs. This work systematically elucidates the geochemical signatures, vertical migration pathways, and quantitative source contributions of heavy metals in mining-disturbed farmlands, delivering solid scientific support for targeted source control, tiered risk management, and soil ecological remediation within the Fenghuang Mining Area. Moreover, the multi-method integrated analytical framework developed herein provides transferable guidance for heavy metal pollution mitigation in global polymetallic mining-agricultural regions with analogous geological and industrial backgrounds.
The agricultural and environmental application of Miscanthus × giganteus biomass ash (MBA) as a soil amendment requires a thorough assessment of its properties, nutrient potential, and associated risks. This study characterizes the elemental composition, pH, cation exchange capacity (CEC), and polycyclic aromatic hydrocarbons (PAHs) content of MBA in comparison with other common biomass ashes (crops, wood, and sewage sludge) referred to the international regulatory standards. The ash exhibits a strong alkaline pH (11.03), suggesting potential to improve soil pH in acid soils, but requires careful controlled application to prevent excessive alkalization. The main nutrients detected include K (5.54%), Ca (2.07%), Mg (0.37%), and P (0.86%), indicating its potential as a soil amendment, though long-term use may cause nutrient imbalances. Micronutrients such as Zn (240.67 mg·kg-1), Mn (297 mg·kg-1), and Cu (33.5 mg·kg-1) are found in concentrations suitable for agricultural use, while potentially toxic elements (PTEs), including Cd, Cr, Ni, and Pb, are below detection limits, thereby reducing the risk of pollution. As (8.3 mg·kg-1) and ΣPAHs (1.63 mg·kg-1) remain within safety thresholds, suggesting a low environmental toxicity of MBA. The low Na content (0.12%) indicates a minimal risk of salinity accumulation, distinguishing MBA from high-sodium biomass ashes. Soil alkalization, disruptions in nutrient balance, and element leaching are risks to be considered. Despite these concerns, its composition is in agreement with established safety guidelines, supporting its feasibility for valorization as a sustainable soil amendment and remediation material. To maximize agronomic benefits and mitigate environmental risks, it is important to utilize the ash, considering site conditions and carry out regular monitoring of the soil.