微生物担持石こう－炭酸カルシウム系複合硬化体のリン除去および有機物除去能

抄録

A crystallization-type phosphorus removal agent was prepared by carbonating a composite consolidated body containing gypsum, calcia and calcium carbonate in the wet condition. We tried to give organic substances removal ability as well as phosphorus removal ability to the composite consolidated bodies by supporting useful microorganisms on the surface the bodies. Microorganisms were supported by immersing samples in a culture solution containing lactobacillus, bacillus natto and saccharomyces. In this study, the effect of water content during carbonation on the water purification property of the consolidated body supported with microorganisms was examined. For the samples immersed in the culture solution, adhesion of microorganisms was confirmed on the surfaces by SEM observation, and therefore, 85% organic substances in a model sewage could be removed efficiently. However, the ratio of phosphorus removal decreased by 30% by immersing in the culture solution, resulting from the collapse of calcium carbonate crystals on the surface as a crystallization site of calcium phosphate. So, the degree of decrease in phosphorus removal ability varied greatly depending on the state of calcium carbonate precipitated on the surface. When carbonation was performed at 30% water content, the large number of fine calcium carbonate crystals precipitated on the surface of the consolidated body. That is, the area of the crystallization site of calcium phosphate was probably large. Therefore, the degree of decrease in phosphorus removal ability was almost 0% in case of carbonation at 30% water content because the surface of calcium carbonate that acts as a crystallization site of calcium phosphate sufficiently remained even after immersing in the culture solution.