Use of Wheat Germ and Chitosan as the Natural Coagulant in Oleochemical Wastewater Treatment

Abstract

Malaysia’s oleochemical processing industry uses crude palm oil as the main source of process feedstocks. Physical–chemical treatment methods such as coagulation and flocculation processes are widely used to pre-treat oleochemical effluent followed by biological treatment to meet Standard A/B as required by the Department of Environment (DOE). Established chemicals that are used include aluminium sulphate and iron chloride as coagulants while the aluminium chloride, iron salts, and polyelectrolytes are used as flocculants. The industry is in constant effort to look into alternative chemicals that are friendly to both human and environment. Natural coagulants such as wheat germ and chitosan are proposed to treat the effluent. The investigations related to the removal rate of turbidity and chemical oxygen demand (COD) between natural and chemical coagulants were carried out. The effluent samples were analysed with the aluminium content. The results showed that the optimum dosage of wheat germ, chitosan, aluminium sulphate and iron chloride were: 2000, 20, 167 and 169 mg/L respectively. The turbidity reduction efficiency percentage using the wheat germ, chitosan, aluminium sulphate and iron chloride were reported at 80.2 ± 30.2, 78.8 ± 32.9, 96.2 ± 2.0 and 90.3 ± 3.9% respectively. The COD reduction efficiency by using wheat germ, chitosan, aluminium sulphate, and iron chloride were reported at 11.4 ± 5.8, 15.7 ± 6.6, 15.7 ± 3.1 and 15.9 ± 3.3% respectively. The findings showed that the effluent samples from natural coagulation process contains of lower aluminium concentration (0.1 ± 0.1 and 0.2 ± 0.1 mg/L) as compared to effluent samples from chemical coagulation process with the aluminium concentration of 2.4 ± 0.4 and 5.5 ± 0.3 mg/L. Thus, the use of wheat germ and chitosan are less hazardous to human health and environment.