Coagulation Performance of Hydrolysed (Alum) and Pre-Hydrolysed (PAC) Coagulants for Ammoniacal Nitrogen (AN) Removal from Matured Leachate

Abstract

Coagulation is commonly used in removing pollutants from matured leachate because of the low biodegradability of leachate that only suits the physical-chemical treatment method. Coagulant types are affecting the removal of pollutants as a consequence of leachate variability characteristics. This research aimed to assess the performance of hydrolysed alum (aluminium chloride) and pre-hydrolysed PAC (polyaluminium chloride) coagulants in AN removal from matured leachate under dosage, pH and settling time. It was found that the optimal conditions for hydrolysed alum were obtained at a dosage of 3000 mg/L, pH 4, settling time 30 minutes with 22% AN removal meanwhile for pre-hydrolysed PAC coagulants were obtained at a dosage of 2000 mg/L, pH 7, time of 20 minutes with 29% AN removal respectively. In conclusion, pre-hydrolysed PAC coagulants performed better in AN removal than hydrolysed alum coagulants.