Clean and effective removal of Cl(-I) from strongly acidic wastewater by PbO2.
Clean and effective removal of Cl(-I) from strongly acidic wastewater by PbO2.
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DOI：
10.1016/j.jes.2022.01.004
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发表时间：
2022-01
影响因子：
6.9
通讯作者：
Jinmin Zhao;Linghao Kong;Xingyun Hu;Xianjia Peng
中科院分区：
文献类型：
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作者：
Jinmin Zhao;Linghao Kong;Xingyun Hu;Xianjia Peng
强酸性废水中含有的污染物Cl（-I）难以去除，严重影响了回收的H2SO 4质量。本文研究了PbO 2对Cl（-I）的去除作用，并探讨了其作用机理。当PbO 2/Cl（-I）摩尔比为2：1时，在50℃下，Cl（-I）的去除率可达93.38%。反应产物的鉴定表明，Cl（-I）被氧化为Cl 2，PbO 2被还原为PbSO 4。用NaOH吸收Cl 2生成NaClO，用于从生成的PbSO 4中再生PbO 2。Cl（-I）通过两种途径去除，即，表面氧化和·OH自由基氧化。PbO 2与OH−反应生成的·OH在Cl（-I）去除中起着重要作用。再生PbO 2经6次再生后，对Cl（-I）的去除效果良好。本研究对氧化法有效去除Cl（-I）提供了深入的认识。
Recycling strongly acidic wastewater as diluted H2SO4after contaminants contained being removed was previously proposed, however, Cl(-I), a kind of contaminant contained in strongly acidic wastewater, is difficult to remove, which severely degrades the quality of recycled H2SO4. In this study, the removal of Cl(-I) using PbO2was investigated and the involved mechanisms were explored. The removal efficiency of Cl(-I) reached 93.38% at 50℃ when PbO2/Cl(-I) mole ratio reached 2:1. The identification of reaction products shows that Cl(-I) was oxidized to Cl2, and PbO2was reduced to PbSO4. Cl2was absorbed by NaOH to form NaClO, which was used for the regeneration of PbO2from the generated PbSO4. Cl(-I) was removed through two pathways, i.e., surface oxidation and •OH radical oxidation. •OH generated by the reaction of PbO2and OH−plays an important role in Cl(-I) removal. The regenerated PbO2had excellent performance to remove Cl(-I) after six-time regeneration. This study provided an in-depth understanding on the effective removal of Cl(-I) by the oxidation method.