Abstract

• This research was aimed to examine the adsorption behaviour of phosphate ion on modified coal fly ash under different operating conditions to determine the optimum condition to remove phosphate ion. The coal fly ash was treated with hydrochloric acid and optimal conditions were found to be 2 M HCl solution, the ratio of coal fly ash and acid solution is 1:2 (w/v) and for 2 h of acid treated time at ambient temperature. Batch adsorption experiments were performed to evaluate phosphate removal efficiency of acid treated coal fly ash. The effect of various adsorption parameters, i.e. pH, adsorption time, adsorbent dose and initial phosphate ion concentration using the acid treated coal fly ash was studied. The maximum removal percent of phosphate ion was achieved 94.03 % at an adsorbent acid treated coal fly ash loading weight of 0.1 g/100 mL, 1 mg L -1 of initial concentration of phosphate solution, pH of 3 and 90 min of contact time at ambient temperature. Coal fly ash (CFA), acid treated coal fly ash (ACFA) and phosphate ion sorpted acid treated coal fly ash (PACFA) were characterized by using modern techniques such as SEM, EDXRF and XRD. According to widen applicability of the proposed method, it can be used for the removal of phosphate from eutrophicated surface water.