采用硫化沉淀法从酸性废水中除砷及其水热成矿稳定化（英文）

Removal of arsenic from acid wastewater via sulfide precipitation and its hydrothermal mineralization stabilization

为实现对含砷酸性废水的安全处理,本文作者提出硫化法沉砷和水热成矿稳定砷的新工艺。在硫化沉淀最佳条件下,废水中99.65%的砷以无定形As2S3的形式沉淀。由于该沉淀在TCLP试验中砷的浸出浓度高达212.97 mg/L,因此,采用水热成矿法提高As2S3的稳定性。结果表明,经矿化的As2S3的砷浸出浓度仅为4.82 mg/L。此外,在矿化剂Na2SO4的作用下,无定形As2S3可转变为As2S3晶体,且砷浸出液浓度进一步降至3.86 mg/L。水热成矿法是稳定硫化砷的有效方法。因此,该工艺在含砷废水的处理中具有较大应用前景。

To achieve a safe treatment of arsenic-containing acid wastewater,a new process was proposed,including arsenic removal via sulfide precipitation and hydrothermal mineralization stabilization.Under optimal conditions of sulfide precipitation,99.65%of arsenic from wastewater was precipitated in the form of amorphous As2S3.The As leaching concentration of amorphous As2S3 in TCLP(toxicity characteristic leaching procedure)test was up to 212.97 mg/L,therefore,hydrothermal mineralization was adopted to improve the stability of amorphous As2S3.The results showed that the As leaching concentration of mineralized As2S3 was only 4.82 mg/L.Furthermore,the amorphous As2S3 could be transformed into crystallized As2S3(orpiment)in the presence of mineralizer Na2SO4.Simultaneously,the As leaching concentration of crystallized As2S3 was further reduced to 3.86 mg/L.Hydrothermal mineralization was an effective method for the stabilization of As2S3.Therefore,this process has a greater application in the treatment of arsenic-containing wastewater.