Phosphate removal by column packed blast furnace slag ‐ I. Fundamental research by synthetic wastewater

Abstract

Abstract In order to remove phosphate ion of secondary effluent, a process consisting of decarbonation by contact CO2‐stripping and phosphate removal using column packed with blast furnace slag was developed, and a synthetic wastewater prepared by K2SO4 , NaHCO3, CaCl2 and KH2PO4 without COD, BOD, SS and TN was used. The decarbonated wastewater was fed to the slag column by upflow, and the retention time in the column, the pH, the concentrations of calcium ion, phosphate ion and total carbonate in influent, were varied and these effects on phosphate removal were investigated.