抄録
The effect of addition to the gypsum was investigated on phosphorous removal properties of wollastonite-type adsorbent. Typical calcium silicate powder, wollastonite, was mechano-chemically activated in air for 24h with a vibration ball-mill. The cakes of the vibration ball-milled wollastonite added with a fair amount of water and gypsum were carbonated at 80°C in 0.33MPa CO2 for 3h. The removal efficiencies of phosphorus for the carbonated specimens were investigated by immersing them in Na3PO4 aqueous solution containing 5ppm phosphorus. After immersing the specimens for prescribed duration in the test solution, the remaining amount of phosphorus in a supernatant liquid was measured by a molybdenum blue method. Ca ion concentrations dissolved from specimens were measured with a selective electrode instruction. In addition, various consolidated bodies were investigated by immersing them in Na3PO4 aqueous solution containing various amounts phosphorus. The obtained results are the following:
(1) The addition of gypsum increase released Ca ion amounts compared with consolidated bodies without gypsum, so, the removal efficiencies of phosphorous for the specimens markedly improve, and we can produce specimens available for Na3PO4 aqueous solution containing various amounts phosphorus by addition of gyrpsum.
(2) Released Ca ion amounts more affect the removal efficiencies of phosphorous than wollastonite amounts.
