硅藻土负载MnFe_(2)O_(4)纳米颗粒活化PMS降解金橙Ⅱ

MnFe_(2)O_(4) NANOPARTICLES SUPPORTED BY DIATOMITE FOR REMOVAL OF ORANGE Ⅱ THROUGH ACTIVATING PMS

采用溶胶-凝胶法制备硅藻土/MnFe_(2)O_(4)复合型催化剂(DMF),以金橙Ⅱ为目标污染物,分析DMF活化过一硫酸盐(PMS)的性能和作用机制。结果表明:1)MnFe_(2)O_(4)颗粒均匀负载于硅藻土上,使DMF具有更好的分散性和活化性;2)DMF对PMS的活化能力优于单一MnFe_(2)O_(4),DMF(1∶1)/PMS体系降解金橙Ⅱ符合准一级动力学模型,且降解速率是MnFe_(2)O_(4)/PMS体系的2.16倍,0.5 g/L DMF和0.5 mmol/L PMS在40 min内对50 mg/L金橙Ⅱ降解率达到93.1%;3)反应体系中存在·OH、SO^(-)_(4)·、~1O_(2)、·O^(-)_(2)4种活性物种,其中·OH和SO^(-)_(4)·起主导作用;4)DMF复合材料具有更好的结构稳定性,金属离子溶出量远低于MnFe_(2)O_(4)。研究结果可为新型高效PMS催化剂在处理工业废水的实际应用提供参考。

Diatomite/MnFe_(2)O_(4) composite catalyst(DMF) was rationally synthesized by sol-gel method.The performance and reaction mechanism of DMF activated peroxymonosulfate(PMS) were degraded with orange Ⅱ as the target pollutant.The results showed that:1) MnFe_(2)O_(4) particles were uniformly loaded on diatomite and DMF had better dispersion and stability;2) DMF had a better catalytic activity to PMS than MnFe_(2)O_(4) so that the degradation rate of DMF/PMS system for orange Ⅱ removal was 2.16 times that of MnFe_(2)O_(4) system,the reaction process could be fitted by the pseudo-first-order kinetic pattern.A degradation rate of 93.1% could be achieved within 40 min for 50 mg/L AO_(2) by 0.5 g/L DMF and 0.5 mmol/L PMS;3) there were four active radicals ·OH、SO^(-)_(4)·、~1O_(2) and ·O^(-)_(2) in the reaction system,and OH and SO^(-)_(4) play the main role;4) DMF had better structural stability and its metal ion dissolution was much lower than MnFe_(2)O_(4).This study paved a way for the practical application of the new PMS activators in industrial wastewater treatment.