改性赤泥负载氧化钴催化剂活化过一硫酸盐降解罗丹明B

Degradation of rhodamine B using peroxymonosulfate activated with cobalt oxide supported on acid-treated red mud

赤泥是制铝工业排放的强碱性固体废弃物,利用改性赤泥制备类芬顿催化剂可以实现赤泥资源化利用。以酸化改性赤泥为载体,采用浸渍法制备了负载氧化钴催化剂。以罗丹明B为目标物,研究了酸化改性赤泥负载氧化钴催化剂活化过一硫酸盐(peroxymonosulfate,PMS)处理罗丹明B的性能,考察了催化剂用量、PMS浓度、罗丹明B初始浓度以及反应温度的影响。结果表明,在催化剂用量为0.05 g/L、PMS浓度为0.1 mmol/L、溶液初始pH为4.8、反应温度为65℃、罗丹明B质量浓度为10 mg/L、反应时间为50 min的条件下,罗丹明B的去除率达到95.9%。淬灭实验结果表明,反应体系中同时存在SO^(-·)_(4)、·OH和单线态氧^(1)O_(2),其中^(1)O_(2)的氧化反应起主导作用。4次循环实验后罗丹明B的去除率仍能维持在80.0%以上。

Red mud is an alkaline solid waste produced during aluminum production,and can be recycled by converting acidified red mud into Fenton-like catalyst.In this study,red mud was acidified using hydrochloric acid and then loaded on cobalt oxides via impregnation method to prepare a heterogeneous catalyst.Peroxymonosulfate(PMS)was activated by the as-prepared catalyst to remove Rhodamine B.The effects of catalyst dosage,PMS concentration,initial Rhodamine B concentration,and reaction temperature on the removal efficiency were investigated.Results show that the removal efficiency of Rhodamine B was 95.9%at the catalyst dosage of 0.05 g/L,PMS concentration of 0.1 mmol/L,initial solution pH of 4.8,temperature of 65℃,Rhodamine B concentration of 10 mg/L,and reaction time of 50 min.Free radical scavenging experiment confirmed the presence of SO^(-·)_(4),·OH,and singlet oxygen(^(1)O_(2))in the reaction system,where ^(1)O_(2) played a major role in the oxidation of Rhodamine B.Even in the third reuse of the catalyst,the removal efficiency of Rhodamine B remained above 80%.