微生物を担持した晶析型脱リン材の水質浄化能にコーティングが及ぼす影響

抄録

Gypsum board is widely used as an excellent building material, but in recent years the amount of waste has been increasing due to the rebuilding of buildings, so it is required to establish a new reuse method. The purpose of this study was to develop a water purification material that can remove phosphorus and organic matters at the same time using a waste gypsum board. In order to improve the shape retention of the gypsum board in water, polyvinyl butyral (PVB) or silica coating was applied to the gypsum board, and the effect of the type of coating materials on the phosphorus and organic substances removal abilities was investigated. After coating, samples were immersed in a sodium carbonate aqueous solution to precipitate calcium carbonate on the sample surface, and then immersed in activated sludge for 5 days to carry microorganisms on the sample surface. Phosphorus and organic matters could be removed with both silica and PVB coated samples. However, when the silica coating was applied, the calcium carbonate layer on the surface was peeled off after the removal experiment, and a decrease in the phosphorus removal ability after carrying microorganisms was observed as compared with the case of the PVB coating. On the other hand, for the PVB-coated sample, no peeling of the sample surface was observed after removal of phosphorus and organic matters, and the decrease in phosphorus removal ability after carrying microorganisms was small. Therefore, PVB coating is considered to be effective in reusing waste gypsum board as a water purification material.