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 (nFe/nCaO2)

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

nFe/nCaO2=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.