재활용 패각의 산-염기치환 반응을 통한 과산화칼슘의 제조와 산소발생 특성

Abstract

The Korean coastal sediment area is apt to be contaminated by prevailing aquafarming and inland eutrophic sources. Furthermore, oyster shells are being overproduced every year with little recycling. Oxygen-releasing compounds (ORCs)are paramount in bioremediation or bioaugmentation. Calcium peroxide, one of the primary ORCs, was prepared usingrecyclable oyster shells via acid?base reactions based on double replacement, and this was followed by oxidation withhydrogen peroxide. Hydrogen peroxide, which is known to be effective as oxidizing agent, required an optimum dosefor higher content of oxygen in the final product, because the literature shows that the oxidative reaction is reversible. A variety of concentrations of HCl and NaOH were examined in stoichiometry for the breakdown of calcium carbonates(or CO2 production) and formation of calcium hydroxide in the initiation reaction. Acid and base overdoses helped theoxygenation reaction to be extended further, thus leading to calcium peroxide with the highest content of oxygen at acombination of 6 N-12 N acid-base treatment. With an elevated temperature, more oxygenated calcium peroxide was likelyto be formed. Carbon dioxide and free oxygen during the experiments were determined with DO probing and gas capturein a water bath.