The Removal of Phosphate and Arsenate from Aqueous Solution Using Silica Based Materials

Abstract

Three silica modified materials (diethyl phenoxy ethyl amine silicate, L1, methylated diethyl phenoxy ethyl amine silicate, L2, and 25,27-bis[N-2(-hydroxy-1,1-bis hydroxymethyl-ethyl) amino-carbonylmethoxy]-calix[4]arene-26,28-diol silica, L3) were synthesised. The extracting properties of L1 and L2 for the removal of phosphates and arsenates from aqueous medium were investigated taking into account several parameters such as mass of materials, anion salt concentration and the pH of the aqueous solution. Experimental data on the uptake of phosphate and arsenate from aqueous solution at 298 K against time were used to calculate the rate constants and the half-life of the extraction process by L1 and L2. The removal capacities of L1 and L2 for these anions from water were found to be 2.35 and 4.48 mmol/g respectively. Final conclusions are given.