The rapid, efficient, and thorough degradation of Bisphenol A (BPA) is challenging. In this study, we prepared an effective peroxymonosulphate (PMS) activation catalyst derived from sawdust containing calcium carbonate. The Co and Cu co-doped sawdust biochar (CoO/CuO@CBC) catalyst could activate PMS quickly, and the degradation rate of BPA reached 99.3% in 5 min, while the rate constant was approximately 30 times higher than in the CBC/PMS and CoCuO_x/PMS systems. Moreover, the interaction between CoO, CuO, and CBC endows the CoO/CuO@CBC catalyst with excellent catalytic performance under different conditions, such as initial pH, temperature, water matrix, inorganic anions, and humic acid, which maintained fast PMS activation via the cyclic transformation of Cu and Co for BPA degradation. The results demonstrated that both the radical (•O₂⁻ and •SO₄⁻) and non-radical (¹O₂) pathways participate in the degradation of BPA in the CoO/CuO@CBC/PMS system. The efficient and stable degradation over a wide range of pH, temperature, and aqueous matrices indicates the potential application of the CoO/CuO@CBC catalyst.

Zn-doped MnCO₃/carbon sphere (Zn-doped MnCO₃/CS) composites were synthesized using a simple hydrothermal procedure. Among various samples (ZM-50, ZM-05, and ZMC-0), the ternary Zn-doped MnCO₃/CS (ZMC-2) catalyst demonstrated excellent visible light-induced photocatalytic activity. This improvement comes from the Zn addition and the conductive CS, which facilitate electron movement and charge transport. The catalyst exhibited efficient degradation of methylene blue (MB) over a wide pH range, achieving a removal efficiency of 99.6% under visible light. Radical trapping experiments suggested that •OH and •O₂⁻ played essential roles in the mechanism of organic pollutant degradation. Moreover, the catalyst maintained good degradation performance after five cycles. This study offers valuable perspectives into the fabrication of carbon-based composites with promising photocatalytic activity.

Peroxymonosulfate (PMS)-based advanced oxidation processes have shown potential for the removal of organic contaminants; however, the preparation of catalysts with high degradation efficiencies and rapid reaction rates remains a challenge. In this study, we have successfully synthesized CoFe bimetallic modified corn cob-derived biochar (CoFe/BC) for the activation of PMS, achieving the rapid and efficient degradation of bisphenol F (BPF). The synthesized CoFe/BC catalyst demonstrated excellent catalytic performance, achieving over 99% removal within 3 min and exhibiting a removal rate of 90.0% after five cycles. This could be attributed to the cyclic transformation of Co and Fe, which sustained rapid PMS activation for BPF degradation, and Co⁰/Fe⁰ played a significant role in the cyclic transformation. Furthermore, the electron paramagnetic resonance tests confirmed that •SO₄⁻ and •OH were the primary reactive oxygen species, while •O₂⁻ played a minor role in BPF degradation. This study highlights the high degradation efficiency, rapid reaction rate, excellent magnetic separation properties, and exceptional reusability of CoFe/BC catalysts for BPF removal, providing valuable insights for practical wastewater treatment.

The fate and risk identification of cyantraniliprole (CYA) and lufenuron (LUF) in pak choi were systematically analyzed through an investigation comprising field trials, dissipation kinetics, and dietary risk assessment. Initially, field experiments across ten Chinese provinces revealed half-lives of 3.04–5.41 d for CYA and 2.02–5.13 d for LUF, with dissipation following single first-order (SFO) kinetics or double first-order in parallel (DFOP) kinetics. Terminal residues (<limit of quantification (LOQ) to 0.29 mg/kg) were below maximum residue limits. Dissipation rates were significantly influenced by temperature, climate, and crop growth stage. Additionally, the multidimensional dietary assessment using deterministic and probabilistic models revealed acceptable long-term risk levels for CYA and LUF among consumer groups (risk quotients < 28.4%). Overall, this first comprehensive study from cultivation to consumption provides crucial insights for rational pesticide use in pak choi.