Due to the lack of affordable and green disposal technologies, high arsenic-containing waste acid from the heavy nonferrous metallurgical smelter causes serious environmental pollution and threatens human health. In this study, a cost-effective and environmentally-friendly solution for simultaneous oxidation and precipitation of arsenic as well as formation of scorodite by adding ferrous sulfate as an iron source is proposed under elevated temperature (170 °C) and pressurized oxygen (1 MPa) conditions. And that the total reaction can be interpreted as 4Fe²⁺ + 4HAsO₂ + 3O₂ + 10H₂O → 4FeAsO₄·2H₂O + 8H⁺. Consequently, the final oxidation and removal efficiency of arsenic reached 98.95% and 97.42%, respectively, resulting in scorodite with an arsenic leaching concentration of 1.4 mg/L in the TCLP leaching test. The results prove that the HO^•, Fe(III) and Fe(IV) produced by the oxidation of Fe(II) is of capable oxidizing As(III) to As(V). Most importantly, the synthetic transformation mechanism of scorodite via a four-stage process is revealed, including the oxidation of As(III), formation of a mixture of amorphous hydronium jarosite and iron arsenate as precursors, partial dissolution of the precursor as well as nucleation and growth of scorodite particles.

由于缺乏可负担的绿色处理技术，重有色冶金冶炼厂的高砷废酸造成严重的环境污染，威胁人类健康。在这项研究中，提出了一种在高温（170°C）和加压氧气（1 MPa）下添加硫酸亚铁作为铁源同时氧化和沉淀砷以及形成臭葱石的经济高效且环保的解决方案。 ） 条件。并且总反应可以解释为 4Fe ²⁺ + 4HAsO ₂  + 3O ₂  + 10H ₂ O → 4FeAsO ₄ ·2H ₂ O + 8H ⁺. 结果，砷的最终氧化和去除效率分别达到98.95%和97.42%，在TCLP浸出试验中得到砷浸出浓度为1.4 mg/L的臭葱石。结果证明，Fe(II)氧化生成的H2O ^{• 、Fe(III)和Fe(IV)能够将As(III)氧化成As(V)。}最重要的是，通过四阶段过程揭示了臭葱石的合成转化机制，包括As（III）的氧化，作为前体的无定形水合黄钾铁矾和砷酸铁混合物的形成，前体的部分溶解以及成核和臭葱石颗粒的生长。