Enhanced atrazine degradation in water by N, P co-doped biochar based on peroxymonosulfate: Performance, mechanism and phytotoxicity reduction

Atrazine (ATZ), a commonly used herbicide, poses significant environmental and health risks due to its persistence in aquatic environments. This study applied peroxymonosulfate-based advanced oxidation technology using N, P-doped rice straw biochar (NP@RSBC700), prepared via one-step pyrolysis, to degrade ATZ. The biochar produced at 700 °C exhibited optimal performance due to its enhanced graphitic structure (I D /I G = 0.77) and physicochemical properties. The NP@RSBC700-activated PMS system achieved a 100 % degradation efficiency of ATZ within a short period of just 2 h. N and P doping synergistically improved active sites, including C O, P-O, graphitic N, pyridinic N, and pyrrole N, alongside a porous structure (180.75 m 2 ⋅g −1 ) and defects, demonstrating the potential of this approach in environmental remediation applications. Liquid chromatography-mass spectrometry revealed three potential ATZ degradation pathways, with reduced intermediate toxicity and bioaccumulation confirming effective detoxification. Hydroponic experiments demonstrated that the biochar not only degraded ATZ efficiently but also mitigated its toxicity on plant seedlings. These findings highlight the multifunctional potential of N, P-doped biochar in PMS-based advanced oxidation processes, combining pollutant degradation with plant health protection.