Abstract:

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.

摘要：

CaO₂作为原位Fenton 氧化修复中H₂O₂持续供源的作用逐渐受到关注。利用亚甲基蓝分光光度法评价了基于CaO₂的Fenton反应中催化剂种类、初始pH值、CaO₂用量、催化剂和CaO₂比例、磷酸缓冲溶液浓度对羟基自由基（HO·）产率的影响。结果表明，采用Fe²⁺作为催化剂，在pH值为4、CaO₂