抄録
Using heated volcanic ash soil with ferrous sulfate that adsorbed phosphoric acid ions, phosphorus regeneration is experimentally examined, and the reuse of used phosphorus adsorbent is investigated. The phosphate adsorption quantity of the used phosphorus adsorbent is high, similar to that of phosphate rock. The phosphorus adsorbent pattern is aluminum-type phosphorus > iron-type phosphorus > calcium-type phosphorus. The ideal desorption liquid for used phosphorus adsorbent is sulfuric acid solution. It completely (100%) desorbs phosphate, but needs a sixfold increase in the amount of what to regenerate phosphate. Additionally, the effect of volcanic ash soil on the growth of Brassica campestris cv. komatsuna is investigated using used phosphorus adsorbent, and the reuse of the adsorbent in agriculture is also discussed. The application of used phosphorus adsorbent to the subsoil of andosol facilitates the growth of komatsuna; this effect is higher than that of superphosphate application. Therefore, used phosphorus adsorbent offers promising advantages for reuse in agriculture.
