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

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SO₄^-· 、·OH和单线态氧¹O₂，其中¹O₂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。

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

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 SO₄^-·,·OH, and singlet oxygen (¹O₂)in the reaction system, where ¹O₂played 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%.