Molecular Regulation of Sulfur Metabolisms Induced by Low-Molecular-Weight Organic Acids on the Diffusion of Perfluoroalkyl and Polyfluoroalkyl Substances at the Water–Soil Interface in Paddy Fields

• • Acetic acid enrichment suppressed PFASs release into overlying water more effectively than oxalic, citric, or lactic acids, with sulfur metabolism contributing 26.06% to PFASs immobilization as determined by ABT modeling. • • Acetic acid reshaped the soil microbial community, enriching sulfate-reducing bacteria and upregulating sulfur reduction gene SULT1A and nitrogen transformation genes nifN, nirI, nthB, promoting sulfate reduction to sulfite and sulfide. • • Sulfite (SO3^2−) oxidation indirectly altered dissolved organic matter (DOM) composition, weakening PFASs–DOM binding and significantly reducing PFASs concentrations in overlying water, as verified under varying sulfur redox conditions. • • The study integrated soil enzyme activity assays, XPS, 3D-EEM, microbial amplicon sequencing, and metagenomics to elucidate the molecular mechanisms, providing a multi-omics framework for assessing PFASs fate in paddy soils.