Phosphorus Adsorption Property of Baked Granulated Substance of Weathered Soil of Tuff

Abstract

  Since the structure of the weathered soil of tuff, which is generated as excavated soil by farm road improvement projects in Mt. Daisen area in Tottori, is easily destroyed, it cannot be reused and is dumped as industrial waste. The soil also easily becomes muddy and pollutes rivers. In this study, we made a baked granulated substance of the soil (BGD) and evaluated its adsorptive capacity for dissolved phosphorus and clarified the following points. 1) The phosphate absorption coefficient of BGD was changed by sintering treatment temperature and became maximum: 6.22gP₂O₅/kg at 500℃. 2) We found that active aluminum played an important role in the phosphorus adsorption of BGD. 3) The concentration of the dissolved phosphorus in the solution was decreased by immersion treatment of BGD. However, the effect failed to continue in repeated uses. 4) BGD can be reused in farmland after adsorption treatment because the amount of available phosphorus in BGD reached 70 to 80% of the amount of the absorbed phosphorus.