Wastewater treatment by Wastewater Treatment Plant, named (INGECO) in Doura refinery suffers from the elevated level of sulphate ion concentrations compared to the recommended EPA  specified (250 mg/L). The annual rate, maximum and peak sulphate concentrations that found to be 360; 425 and 550 mg/L respectively. In this study samples prepared from industrial wastewater and the average, maximum and peak sulphate concentrations to be used in chemical precipitation process by using BaCl2 or Al(OH)3. Results obtained from BaCl2 treatment refer to the optimum (dosage, mixing time and mixing speed) to be used in sulphate removal for reuse purpose were (1.5 g/L, 1.2 hr and 80 rpm), (2.25 g/L, 1.5 hr and 90 rpm) and (3.0 g/L, 2 hr and 90 rpm) for each of average, maximum and peak concentrations respectively. Whereas for disposal purpose, were (0.36 g/L, 15 min and 100 rpm), (1.1 g/L, 15 min and 70 rpm), (1.72 g/L, 15 min and 90 rpm) respectively. This process was achieving of highly sulphate removal, but expensive. Whereas the results obtained by using Al(OH)3 indicated unsuitability for treated refinery wastewater treatment of low sulphate concentrations and neutral pH.