锰氧化物负载聚苯胺选择性氧化硫化物的效能及机理

目前关于含硫废水处理技术的研究已取得有效进展，但难以在去除含硫污染物的同时实现硫资源的回收利用。为此，通过化学浸渍法制得了锰氧化物负载聚苯胺(Mn_xO_y-PANI)催化剂。XRD、FTIR、XPS和SEM表征结果表明，Mn_xO_y已成功负载于PANI载体。以空气为氧化剂，探究了该催化剂对含硫废水(以Na₂S为模拟污染物)的选择性氧化性能。结果表明：Mn_xO_y-PANI催化剂表现出优异的Na₂S选择氧化性；当催化剂用量为0.2 g∙L⁻¹、Na₂S初始质量浓度为100 mg∙L⁻¹时，240 min内S²⁻可被完全氧化为单质硫(S₀)。Mn_xO_y-PANI反应后的XPS、XRD、Raman表征结果证明，S₀在催化剂上稳定存在。此外，考察了催化剂投加量、Na₂S初始浓度、反应温度、初始pH和不同反应气氛对催化氧化Na₂S的影响。循环实验结果表明，Mn_xO_y-PANI具有较好的稳定性。最后，提出了选择性氧化的可能反应机理，为含硫废水的治理和回收提供参考。

Efficiency and mechanism of sulfide selective oxidation by manganese oxides supported polyaniline

An effective progress has been made for sulfide wastewater treatment technology development, but the recovery of sulfur resources is hard to be achieved while alleviating environmental pollution. Here a manganese oxides supported polyaniline material(MnxOy-PANI) was prepared by a chemical impregnation method. XRD, FTIR, XPS and SEM results indicated that manganese oxides were successfully loaded on the polyaniline substrate. When air was taken as the oxidant, effect of catalyst on sulfide wastewater (Na2S as simulated contaminant) selective oxidation was investigated. The results demonstrated that MnxOy-PANI catalyst had an excellent catalytic activity and selectivity on Na2S oxidation. When the catalyst dosage was 0.2 g∙L-1 and the initial Na2S concentration was 100 mg∙L−1, S2− could be completely oxidized to element sulfur(S0) within 240 minutes. S0 existence on catalyst was confirmed by XPS, XRD and Raman detection of used MnxOy-PANI. Besides, the influences of catalyst dosage, reaction temperature, initial Na2S concentration, initial pH and different reaction atmospheres on the catalytic oxidation of Na2S were studied. Cycling experiments suggested that MnxOy-PANI had a superior stability. Finally, the possible mechanism of selective oxidation was proposed, providing a new insight into the treatment and recovery technology of sulfide wastewater.