Use of alternative aluminium based chemicals in coagulation with particular reference to phosphorus removal

Abstract

Abstract Four raw sewage samples from various parts of England and containing moderate and high phosphate levels have been subjected to chemical flocculation, using a range of aluminium based chemicals, under standard laboratory jar test procedures. Total and orthophosphate levels, as well as pH, suspended solids, floc size and COD have been measured after treatment with aluminium sulphate, polyaluminium chloride (PAC) and aluminium chlorohydrate (ACH) over a wide dose range. The superior flocculation with PAC gave the best overall performance, aluminium sulphate was second and ACH third.