亚甲基蓝光度法研究基于CaO2的Fenton反应条件

Study on condition of CaO_2-based Fenton reaction by methylene blue spectrophotometric method

The potential of calcium peroxide(CaO₂)as a source of hydrogen peroxide(H₂O₂)in Fenton oxidation has been gradually taken note.In order to understand the characteristics of CaO₂-based Fenton reactions, experiments were conducted using methylene blue spectrophotometric method to investigate effect of catalyst type, initial pH, CaO₂ dose,molar ratio of catalyst to CaO₂ (n_Fe/n_CaO2), and phosphate buffer concentration on production of hydroxyl radicals(HO·).The results showed that under the experimental conditions Fe²⁺ had better catalytic ability than Fe³⁺ and Cu²⁺.The optimal Fenton reaction conditions were:Fe²⁺ as catalyst,initial buffer pH=4,CaO₂ dose 1 mmol·L^-1,n_Fe/n_CaO2=1/5,phosphate buffer concentration 40 mmol·L^-1.It was also indicated that the release of H₂O₂ and Fenton reaction were regulated by the dissolution process of CaO₂ that could be a potential substitute for H₂O₂ in in-situ Fenton oxidations, because of decrease of H₂O₂ loss as well as negative impact of Fenton processes on the environment.