Journal of hazardous materials最新文献

With the growth of the selenium product market, the development and utilization of selenium resources have attracted widespread attention. Electroadsorption has emerged as an innovative method for adsorbing Se(IV) from saline systems. In this study, an electric potential was directly applied to the active material electrode to facilitate the adsorption and desorption of Se(IV) ions. Magnesium aluminum layered double hydroxide (LDH) is a cost-effective material with high selectivity and excellent adsorption performance. Herein, magnesium aluminum LDHs intercalated with SO₄^2- (MgAl-SO₄^2--LDHs) were synthesized via a hydrothermal reaction. The electrochemical and adsorption properties of MgAl-SO₄^2--LDHs were evaluated in a simulated brine containing 100 mg Se/L and natural selenium-containing brine from Daba Songnuo Salt Lake (Xinjiang, China).The results demonstrated that, compared with static adsorption, the Se(IV) adsorption capacity of MgAl-SO₄^2--LDHs increased by 60.82 % when a positive voltage of 1.0 V was applied. Furthermore, the MgAl-SO₄^2--LDHs electrode retained 93.51 % of its adsorption efficiency after five adsorption-desorption cycles. The adsorption mechanism of MgAl-SO₄^2--LDHs was analyzed using electrochemical measurements combined with characterization techniques including XRD, XPS, TGA, and FTIR. Theoretical calculation results revealed that a large number of Se(IV) adsorption sites within the interlayers of MgAl-SO₄^2--LDHs remain unutilized. It is anticipated that the Se(IV) adsorption capacity of MgAl-SO₄^2--LDHs can be further enhanced by adjusting their interlayer spacing.This study presents a novel method for the electrochemical adsorption of Se(IV) using magnesium aluminum LDH as an adsorbent and provides new insights into its underlying adsorption mechanism.

The recovery of soil health in multi-contaminated sites remains a critical environmental challenge due to the simultaneous presence of organic and inorganic pollutants. While laboratory-scale experiments provide promising insights, in-field long-term validation is essential to assess soil health recovery under real conditions. In this study, a previously optimized phytoremediation approach was applied in a multi-contaminated site to evaluate its effectiveness in reducing pollutant loads and restoring microbial communities. The design included three treated pilot areas and an untreated control. Metaproteomics analyzed microbial functional activity and taxonomic shifts, supported by a protein extraction protocol for complex matrix. Results showed a marked reduction of contaminants: the sum of polychlorinated biphenyls (PCBs) decreased from 8.35 to 7.68 mg/kg in the control after 5 years, while in treated pilots areas it dropped to 0.68 mg/kg. Among heavy metals, significant declines were observed when comparing the untreated bulk control (B1) with the pilot areas treated through the biotechnological phytoremediation approach, with average reductions of about 92 % for mercury, 70 % for cadmium, 56 % for zinc, and 61 % for lead. Metaproteomic analysis revealed a restored microbial metabolic profile in treated soils, with increased abundance of metabolic enzymes (e.g., GAPDH, isocitrate dehydrogenase), stress proteins (GroEL, HSP70), and biosynthetic enzymes for amino acid and nucleotide production. Microbial taxa enriched in treated areas included Pseudomonas knackmussii and Microbacterium hydrocarbonoxydans. Conversely, control soils showed stress-dominated proteomes with limited metabolic capacity. These findings support the efficacy of phytoremediation and demonstrate the power of metaproteomics in monitoring ecological recovery.

Heavy metal contamination, especially cadmium (Cd), in agricultural soils poses a severe threat to food security and sustainable agriculture. This study explores the spatial heterogeneity of Cd concentrations in soils across China and identifies the key influencing factors. We analyzed a dataset of 669 soil samples collected between 2010 and 2021 using GeoDetector and GeoTree models to examine spatial variations and the interactions among natural and anthropogenic drivers. Our results reveal substantial regional heterogeneity in the factors affecting Cd levels. Anthropogenic activities dominate Cd accumulation in North and Southwest China, while lithology and climatic interactions govern contamination in the Northeast and Central-South. Key nonlinear interactions between fertilizers, pesticides, and industrial emissions exacerbate the risks of Cd contamination. We propose region-specific mitigation strategies integrating soil lithology, agricultural practices, and industrial policies in accordance with Sustainable Development Goals (SDGs). This study advances the mechanistic understanding of Cd dynamics in heterogeneous environments and provides actionable frameworks for global agricultural sustainability.

Feroxyhyte is an Fe(III) oxyhydroxide mineral capable of immobilizing large amounts of Sb(V). However, the mechanisms governing the uptake of Sb(V) by feroxyhyte have not been systematically examined and are poorly understood. This study presents the first investigation of Sb(V) uptake by feroxyhyte through both sorption and coprecipitation processes across an environmentally-relevant range of Sb(V) loadings. Antimony K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy revealed that Sb(V) sorption and coprecipitation (at all loadings) involved the development of edge and corner sharing linkages between Sb^V(O,OH)₆ and multiple Fe^III(O,OH)₆ octahedra. The Sb K-edge EXAFS results indicate that Sb(V) coprecipitation involved incorporation into feroxyhyte's structure via heterovalent Sb(V)-for-Fe(III) substitution, while Sb(V) sorption likely involved occupancy of vacant octahedral sites in feroxyhyte's near-surface structure. As a result of these uptake mechanisms, both sorbed and coprecipitated Sb(V) displayed very strong resistance to desorption via ligand exchange when exposed to SO₄^2-- or PO₄^3--rich solutions (during a commonly-used sequential extraction scheme). Overall, these findings provide new insights into Sb(V) uptake by feroxyhyte and highlight the role that feroxyhyte can potentially play in treating Sb(V)-contaminated water or stabilizing Sb(V) in contaminated soil, sediment and geogenic waste.

In electrochemical oxidation (EO) wastewater treatment, the more recent 2.5D electrode system relying on appropriate amount of physically fixed micro/nano-scale particles on the main electrode surface offers several key advantages over conventional 2D/3D electrode system, such as prominent versatility and recyclability. However, the full potential of the 2.5D electrode system has not been released so far due to the insufficient utilization of the massive inner active sites. To overcome this challenge, in this study, a novel 2.5D electrode flow-through reactor coupling system (2.5D-FT system) was developed, which featured by a hierarchical porous electrode architecture (novel Sb-SnO₂ coated molecular sieve particles loaded on porous RuO₂-TiO₂ or Sb-SnO₂ main electrode) and a staggered-flow-enhanced mass-transfer paradigm, allowing pollutants to fully contact the numerous inner active sites. Results show that the molecular sieve based particles greatly increases the active sites and reduces the electrode impedance. Various model pollutants including acidic red G, bisphenol A, tetracycline, and ciprofloxacin could be degraded more efficiently (e.g., up to 100 % removal) by a single-pass EO process. The enhancement of radical pathway (•OH, •O₂^-) and non-radical pathway (¹O₂), as well as the direct electron transfer (DET) process originating from the hybrid composition and unique structure of the novel 2.5D-FT system, is confirmed by quenching experiment results and multiphysics simulation results. In addition, results of anti-inference and durability tests, energy consumption evaluation, real wastewater treatment and toxicity assessment demonstrate the competitive practicability of the novel 2.5D-FT system.

The rising incidence of multimetal contamination highlights limitations of static dose-addition (TU-CA) ecotoxicological models, which fail to capture concentration-dependent nonlinear interactions. Using short-term phytotests with Brassica napus and Sorghum bicolor in representative purple soils, this study quantifies concentration-dependent interactions among Cd, Pb and As under single and combined exposures, and develops a concentration-driven mechanistic framework. This study proposes the "functional dominance structure" and a nonlinear toxicity-regulation model driven by limitation-interference-reconfiguration, incorporating a sign function and TU-RGR residual correction to reconcile theoretical predictions with observed responses. Single Cd exposure elicited B. napus at low doses (EC₁₅₀ shoot/root = 6.75/1.62 mg·kg⁻¹) with attenuated effects at higher concentrations, whereas S. bicolor showed no significant response. Pb and As induced continuous dose-dependent inhibition in both species, with As exhibiting the highest toxicity (IC₅₀ for B. napus shoots/roots = 115/82 mg·kg⁻¹; S. bicolor = 218/134 mg·kg⁻¹).All metal combinations exhibited nonlinear shifts from low-dose buffering or synergy toward pronounced antagonism at higher doses (toxicity ranking: Cd-As > Cd-Pb > Cd-Pb-As > Pb-As). Functional dominance is characterized by As acting as the primary toxicant, Cd functioning as a modulator, and Pb serving as an auxiliary competitor; sensitivity patterns were consistent across species and organs, with roots generally more vulnerable.This concentration-driven framework enhances mechanistic risk assessment and can inform rapid field triage and prioritized remediation strategies for multimetal-contaminated soils.

PM_2.5 and its major component nitrate both pose serious threats to human health. Despite progress under China's Clean Air Action Plan since 2013, severe haze events still occur frequently, with nitrate aerosols showing limited response to NOx reductions. Quantifying trans-regional transport's contribution to nitrate pollution remains challenging. Here, we conducted dual isotopes of nitrate collected simultaneously during winter in the North China Plain (NCP) and the Yangtze River Delta (YRD). The results suggested that nocturnal chemistry dominated nitrate formation in both regions. The NO₃+HC process contributed ∼20 % NCP, but negligible in the YRD. While nitrate sources remained stable between clean and haze days in the NCP, local mobile sources showed a higher contribution during haze than during clean days in the YRD. Trans-regional NO₂ from the NCP contributed ∼30 % to the YRD on average (higher on clean days, lower on haze days). Crucially, at the onset of severe YRD haze, transported NCP nitrate particles contributed up to 90 %. Our findings underscore the significant role that trans-regional NO₂ transport from the NCP plays in nitrate aerosol formation in the YRD, emphasizing the need for regional coordination in air quality management.

Parental exposure to permethrin, a widely used insecticide, has been epidemiologically associated with metabolic disorders; however, whether parental permethrin exposure exerts long-term health consequences on offspring and the underlying mechanisms remain unclear. Here, we demonstrate that preconception permethrin exposure reprograms offspring metabolism via gut microbiota-mediated disruption of the tryptophan-indole axis. Offspring from exposed parents displayed increased adiposity, glucose intolerance, and dyslipidemia, with more pronounced effects in males. Multi-omics profiling revealed enrichment of Clostridia and sex-specific alterations in microbial tryptophan metabolism, including decreased levels of indole and indole-3-acetic acid (IAA) in males, and elevated 5-hydroxyindole-3-acetic acid (5-HIAA) in females. Microbiota-depleted mice receiving isolated Clostridia from exposed donors recapitulated the metabolic phenotype, establishing a causal role for gut microbes. Notably, the administration of Lactobacillus plantarum Y1 restored IAA levels, and reversed host metabolic dysfunction. Supplementation with IAA alone similarly ameliorated the phenotype. These findings identify the Clostridia-tryptophan-IAA axis as a critical microbiota-host interface disrupted by environmental toxicants and highlight its therapeutic potential for mitigating intergenerational metabolic risk.

Polyionenes are polymers with antibacterial properties that hold great promise for the development of applications aiming to preserve against microbial surface contamination. In this study, the effect of 6-6 polyionene (PI 6-6) on a model Gram-negative bacterium, Escherichia coli, was deciphered using next-generation, label-free shotgun proteomics. Cells were exposed to two sub-minimum inhibitory concentrations (MIC) of the polymer before performing comprehensive proteomic analysis. Under these conditions, the abundance of up to 30 % of the proteins detected was significantly modulated compared to untreated controls. The most strongly impacted biological processes were central metabolism and cellular information processing. Exposure to PI 6-6 induced the production of reactive oxygen species depending on the PI 6-6 concentration. At 0.5x MIC, enzymes involved in hydrogen peroxide detoxification, polyamine and hydrogen sulfide biosynthesis, and sulfur metabolism, were up-modulated. At 0.75x MIC, a higher level of oxidized methionine was detected than in controls. Up-modulation of CspA RNA chaperone alongside other proteins linked to RNA metabolism and ribosome biogenesis was also observed. A large fraction of proteins was also down-modulated under both concentration conditions, with the majority of the top ten down-modulated proteins overlapping between the two treatments. These proteins primarily participate in the glyoxylate/dicarboxylate metabolism and propanoate metabolic pathways, which are both key routes for energy production and carbohydrate metabolism.

Heavy metal(loid)s (HMs) solid-liquid partitioning is crucial for ecological risk assessment in large-scale rivers. However, the roles of microbial communities (generalists vs. specialists) and dissolved organic matter (DOM) composition in regulating HMs dynamics remain unclear. We investigated 77 aquatic sites across the Yangtze River (>1000 km), analyzed HMs distributions and DOM composition, as well as elucidated the mechanisms of HMs solid-liquid partitioning driven by microbial generalist-specialist. HMs primarily originated from natural sources, with limited anthropogenic influence. Community structures, diversity, and metabolic characteristics of bacteria and eukaryotes differed substantially between water and sediments. Bacterial specialists and eukaryotic generalists dominated their respective community formation. From sediments to water, changes in metabolic abundance of bacteria and eukaryotes are key drivers of HMs dynamics and DOM composition, and different taxa influence HMs distribution via distinct pathways. Bacterial specialists indirectly promote HMs retention in sediments through the mediation of protein-like substances. In contrast, eukaryotic generalists directly drive HMs migration into water. Although ecological risks in water were relatively low, most HMs still pose a migration risk from sediments to water, especially As, Cd, and Hg. This study highlights the key roles of microbes and DOM in regulating HMs dynamics, advancing riverine HMs fate understanding.