2017 年 66 巻 6 号 p. 383-388
Recently, phosphorus and organic substances are the origin of water pollution and have caused various diseases in closed area. Therefore it is essential to establish a method for the removal of phosphorus and organic substances in waste water. In this study, we attempted to support microorganism onto gypsum-calcium carbonate composite bodies and discussed the removal properties for phosphorus and organic substances. Microorganisms were supported on the gypsum-scallop shell composite bodies by immersing a culture solutions containing saccharomyceto, bacillus natto and lactobacillus for various time. The effects of particle size of scallop shell powder and immersing time in the culture solution were investigated on the removal properties for phosphorus and organic substances. The removal performance for organic substances of the gypsum bodies increased with increasing the immersing time in the culture solution. However, the phosphorus removal capacity decayed on immersing in the culture solution. The lowering rate of the phosphorus removal capacity increased with increasing the particle size of scallop shell powder and immersing time in the culture solution. When the amount of adhering microorganism increased, the coarse gained scallop shell exposed on the surface of the gypsum bodies, which act as the site for the precipitation of calcium phosphate, was fully covered with microorganisms. Therefore, the phosphorus removal efficiency drastically decreased on immersing in the culture solution for longer durations. On the other hand, because fine scallop shell powder effectively exposed on the surface, the decreasing rate phosphorus removal capacity was relatively small. There is the optimum at particle size of scallop shell powder and the immersing time of culture solutions in producing phosphorus and organic matter removal properties.