Geochemical Drivers Govern Redox-Mediated Arsenic Transformation in Multivariate Sourced Organic-Amended Paddy Soils

作者：Muhammad Mahroz Hussain, Xing Yang, I. Bibi, Maham Shahid, H. X. Wang, Shengsen Wang, Sabry M. Shaheen, Nabeel Khan Niazi, Jörg Rinklebe · 发表于：ACS Omega · 年份：2025 · DOI：10.1021/acsomega.5c07082 · 被引用次数：2 · 研究领域：Arsenic contamination and mitigation、Heavy metals in environment、Mine drainage and remediation techniques

High Resolution Image Download MS PowerPoint Slide Sustainable remediation of toxic metal(loid)-contaminated paddy soils using biowastes is of great importance from both agricultural and environmental perspectives. The redox-mediated interactions between organic amendments, with multivariate sources (i.e., biogas slurry (BGS), rice husk-biochar (RH-BC), cow dung (CD)) and geochemical drivers may influence arsenic (As) mobilization under dynamically changing redox situations, such as in paddy soils. Here, we explored the impact of BGS, RH-BC, and CD on the mobilization pathway of As in a contaminated paddy soil under a wide range of soil redox potentials ( E h: −252 mV to +512 mV), using an automated biogeochemical microcosm system. The partial least-squares-path model (PLS–PM) was used to identify geochemical drivers, which govern As mobilization under reduced and oxidized conditions. Results revealed that As mobilization in the unamended (control) soil was higher under reduced conditions ( E h ≤ +100 mV; dissolved As = 4.2–9.2 mg L –1 ) than that in oxidized conditions ( E h ≥ +100 mV; dissolved As = 3.8–6.7 mg L –1 ). With CD addition, the concentration of dissolved soil As decreased significantly by 19–62% at E h < 0 mV, followed by RH-BC (12–54%) and BGS (34–49%) compared to control. Temporal increase in pH under moderately reduced conditions ( E h > +100 mV) led to a maximum decrease in dissolved As concentration with CD (36–77%), and it ranged from 18 to 75% and 29 to 4...