Stimulated Growth of Aerobic Microbes Using Calcium Peroxide

With continuous and slow oxygen-release characteristic, calcium peroxide （CaO2） has been a new source of supplying oxygen for aerobic microbes in bioremediation of contaminated groundwater. Batch experiments were conducted to evaluate the oxygen-release rate of CaO2reacting with water, the regulation of high pH, as well as the growth of mixed aerobic microbes in the medium containing CaO2, The results show that the oxygen-release process of CaO2 comprises three phases. In the first phase, dissolved oxygen levels of water increased sharply, and average oxygen-release rates increased as the adding weight of CaO2 increased, However, the rates almost kept invariable in the latter phases and were approximately 0.48; and 0. 084 mg O2·h^-1, respectively. As the necessary components of medium, potassium dihydrogen phosphate （KH2PO4 ） and amrnoniurn sulphate （（NH4）2SO4） at a certain ratio could regulate pH caused by CaO2 from 12, 1 to the range of 6.5 -8.5, which is helpful for microbial growth, In addition, diauxic growth curve observed in the medium containing CaO2 suggested that the growth of mixed aerobic microbes could be stimulated by the addition of CaO2.