Ammonium dibutyl dithiophosphate (ADD) is one of the most important flotation reagents in sulfide mineral processing, causing severe environmental pollution. In this study, natural pyrrhotite (NP)-activated peroxydisulfate (PDS) was applied to treat ADD, which can alleviate mine tailing problems and reduce the cost of treating mine wastewater. PDS can be efficiently activated by NP for ADD degradation, achieving complete ADD removal with 0.35 g/L NP and 1.0 mM PDS. The PDS activation not only occurred in solution but on the NP surface. Dissolved Fe²⁺, dissolved Fe³⁺, surface-bound Fe²⁺, and surface-bound Fe³⁺ had been undergoing interconversion as the degradation reaction proceed. The generated sulfate radicals and hydroxyl radicals synergistically remove ADD in the NP/PDS system over a wide pH range. The excess O₂ might cause the transformation of ${\mathrm{S}{\mathrm{O}}_4}^{\bullet -}$ to ${\mathrm{S}{\mathrm{O}}_3}^{\bullet -}$ in the NP/PDS/ADD system. Based on the density functional theory (DFT) calculation and the identification of intermediates, a pathway of ADD degradation in the NP/PDS system is proposed.

二丁基二硫代磷酸铵（ADD）是硫化物矿物加工中最重要的浮选剂之一，对环境造成严重污染。在这项研究中，天然硫铁矿（NP）活化的过氧二硫酸盐（PDS）用于处理ADD，可减轻矿山尾矿问题并降低处理矿山废水的成本。NP可以有效地激活PDS来降解ADD，用0.35 g / L NP和1.0 mM PDS可以完全去除ADD。PDS活化不仅发生在溶液中，而且发生在NP表面。溶解的Fe ²⁺，溶解的Fe ³⁺，表面结合的Fe ²⁺和表面结合的Fe ³⁺随着降解反应的进行，己进行了相互转化。所产生的硫酸根和羟基在很宽的pH范围内协同去除NP / PDS系统中的ADD。过量的O ₂可能导致${\mathrm{小号}{\mathrm{Ø}}_4}^{\bullet --}$ 至 ${\mathrm{小号}{\mathrm{Ø}}_3}^{\bullet --}$在NP / PDS / ADD系统中。基于密度泛函理论（DFT）的计算和中间体的鉴定，提出了NP / PDS系统中ADD降解的途径。