Development of Control Technology of Phosphorus in Water

수중의 인 제어기술 개발

In this study the feasibility of usage of raw sludge (sludge from water treatment plant) and chalk from schools and institutes was investigated to remove the phosphorus in water and wastewater. In this study phosphorus removal efficiencies of sludge and chalk were investigated by changing various factors. The time to reach the equilibrium using chalk and raw sludge under different pHs was obtained. Based on this result, Freudlich adsorption isotherm was applied. Results showed that a portion of phosphorus was removed by adsorption to chalk and raw sludge. The phosphorus removal efficiency using calcinated chalk was about three times higher than that of chalk. It means that some portion of $CaCO_3$ contained in chalk was converted to CaO by calcination and this was proved by X-ray diffraction experiment. About 90% phosphorus removal was observed using sludge and calcinated chalk respectively while about 20% phosphorus removal efficiency was achieved using chalk from the water sample in Lake Sihwa.