Industrial soil is susceptible to acid or alkali pollution, but studies focused on the remediation of such soil are still limited. This manuscript investigated the neutralization effect of five agents (hydrochloric acid, citric acid, ferrous sulfate, calcium superphosphate and raw gypsum) to alkali polluted soil. The results showed that regarding the initial pH after the neutralizing agent addition, it was better to set it lower than the target, as the pH would rebound. None of the five agents caused an obvious increase in the heavy metal contents of the leachates, but they all caused an increase in electrical conductivity, which indicated an increase in soil salinity. The leachates showed a luminous gain to Vibrio fischeri. However, remediation with hydrochloric acid would cause significant inhibition of germination and root elongation of pakchoi. In addition, the addition of neutralizing agents reshaped the soil microbial community structure in different patterns. Soils treated with hydrochloric acid and ferrous sulfate seemed to improve the microbial richness. The neutralization might be favorable for the biodegradation of polycyclic aromatic hydrocarbons (PAHs), which usually coexist in industrial contaminated soil. In general, the neutralization of alkaline industrial soils using ferrous sulfate, superphosphate and gypsum brought minimal environmental risk, among which ferrous sulfate was the first recommendation in industrial soil after a comprehensive comparison.

Alkali-activated persulfate (PS) is widely used in situ in chemical oxidation processes; however, studies on the innovation of the alkali activation process are very limited. Two supported solid superbases, namely KNO₃/γ-Al₂O₃ (KAl) and KNO₃/SBA-15/MgO (KSM), respectively, were prepared and used to activate persulfate to degrade DCF in this work. The results showed that the superbases elevated the solution pH once added and thus could catalyze persulfate to degrade diclofenac efficiently above pH 10.5. The catalytic efficiency of KAl was close to that of sodium hydroxide, and that of KSM was the highest. The mechanism might be that, in addition to raising the solution pH, some potassium existed as K₂O₂, which had a strong oxidizing effect and was conducive to DCF removal. Hydroxyl, sulfate and superoxide radicals were all found in the reaction system, among which hydroxyl might play the most important role. The material composition ratio, common anion and humic acid all had some influences on the catalytic efficiency. A total of five intermediates were found in the KSM/PS oxidation system, and six oxidation pathways, which were hydroxylation, dehydrogen, dechlorination, dehydration, decarboxylation, and C-N bond breakage, might be involved in the reaction process. Several highly toxic oxidation products that should be paid attention to were also proposed.

Developing efficient and recyclable periodate (PI)-based advanced oxidation processes (AOPs) for the removal of emerging organic pollutants (EOPs) has attracted considerable attention. However, the structure–activity relationship of single-atom catalyst in PI-AOP systems remains poorly understood. In this study, a hollow carbon-supported single-Fe atom catalyst (HCFe800) was synthesized and applied for PI activation toward bisphenol A (BPA) degradation. Under neutral pH and ambient temperature, HCFe800 enabled complete removal of BPA within 1 min, achieving a degradation rate constant (k) of 5.094 min⁻¹—approximately 3 and 10 times higher than that of Fe-free and solid control catalysts, respectively. After normalization, the apparent degradation rate constant was 1–3 orders of magnitude greater than those of previously reported catalysts. The optimized Fe doping amount and pyrolysis temperature facilitated the formation of atomically dispersed FeN₄ sites, which outperformed Fe clusters and iron oxides in catalytic activity. The hollow porous structure further enhanced the exposure of active sites, contributing to the exceptional performance. The HCFe800/PI system remained highly effective across broad pH (3–7) and temperature (5–35 °C) ranges and in the presence of 100-fold concentrations of common inorganic ions. Mechanistic studies revealed that the main reactive species were ¹O₂, O₂^•−, and IO₃^•, with negligible involvement of high-valent Fe species. Eight less-toxic BPA degradation products were identified. Moreover, the system was extendable to various other EOPs and exhibited excellent recyclability via thermal regeneration. This work provided fundamental insights into designing and applying single-atom catalysts for PI-based advanced treatment of EOPs.

The Erguna River, a Sino-Russian transboundary river, is vital for regional ecology, but land use impacts on its water quality remain unclear. This study aimed to reveal their response relationship. Using ArcGIS/ENVI, it classified land use in 2010 and 2016 into six types, and applied Pearson correlation to 10 monitoring sections’ water quality data. Results showed land use–water quality correlations were temporally and spatially variable: correlations weakened with increasing buffer distance, with the strongest associations within 1000 m. From 2010 to 2016, grassland shifted from a positive (water-purifying) to negative (pollutant-source) impact on water quality (BOD₅ and arsenic), which was driven by area reduction and overuse; forestland transitioned from no significant effect to a positive (pollutant-intercepting) role, attributed to area expansion. Arable and construction land showed no significant correlations with water quality, due to low proportions of construction land in cross-border areas, and arable land is mostly distributed in areas far from the riverbank. This study provides critical scientific support for transboundary water resource cooperation and targeted ecological management of the Erguna River Basin.

Antimony (Sb) is a toxic metalloid and has become an increasingly prevalent contaminant in ecosystems. Previous studies have reported that Sb has severe toxic effects on plant growth. However, the molecular mechanisms of the response to Sb stress in plants still remain unclear. In the present study, common bermudagrass (Cynodon dactylon [L.] Pers.), ‘Yangjiang’ cultivar, was treated with 200 mg/mL of antimony potassium tartrate solution. Integrated metabolomic and transcriptomic analysis was conducted to investigate the mechanisms of the Sb stress response of bermudagrass. The results showed that, after Sb stress treatment, soluble protein content, malondialdehyde (MDA) content, and catalase (CAT) activity increased by 180.56%, 280%, and 112.61%, respectively, compared to the control. Meanwhile, transcriptomic and metabolomic analyses identified numerous differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) that were involved in the Sb stress response of bermudagrass, and many pathways, such as the carbon metabolism, photosynthesis and alanine, aspartate, and glutamate metabolism pathways, were also identified to be related to the Sb stress response of the bermudagrass plant by KEGG and GO enrichment. Overall, the present study revealed that photosynthesis and amino acid metabolism pathways play important roles in the Sb stress response of bermudagrass.