以硫酸亚铁(FeSO4·7H2O)和红茶渣为原料，采用限氧高温热解技术制备了系列磁性生物炭（Fe-BC0.72、Fe-BC0.55、Fe-BC0.25）并将其用于活化过二硫酸盐（PS）降解罗丹明B（Rh B)）。考察了Fe3O4（Fe）与生物炭(BC)的质量比、Fe-BC投加量、过硫酸钾用量、溶液pH、温度等参数对BC-Fe活化PS降解Rh B效果的影响。结果表明，当Fe3O4与生物炭(BC)的质量比为0.55、Fe-BC用量为0.021 3 g、PS用量为0.030 2 g，pH为5、反应温度为30 ℃时Fe-BC0.55对RhB (40 mg·L-1)的降解效果最佳，反应90 min时的降解率为98.8%。将Fe-BC0.55磁性分离、循环使用5次，对RhB的降解率为75%。
Series of magnetic biochar (Fe-BC0.72, Fe-BC0.55 and Fe-BC0.25) were prepared by solid-phase grinding coupled with pyrolysis of ferrous sulfate and red tea residue. The effects of mass ratio of Fe3O4 and BC, Fe-BC and persulfate (PS) dosages, solution pH and temperature on rhodanine B(Rh B) degradation were investigated in the system of Fe-BC and PS. The results showed that the degradation rate of Rh B was ideal as the mass ratio of Fe3O4 and BC was 0.55, Fe-BC0.55 dosage was 0.021 3 g and PS mass was 0.030 2 g at pH5 and the reaction temperature of 30 ℃. The degradation rate of RhB was 98.8% at the reaction time of 90 min. The degradation rate of Rh B was 75% after BC-Fe0.55 was recycled for 5 times via magnetic separation.