Separation Science and Technology, Vol.47, No.5, 700-708, 2012
Reduction of COD and TSS from Paper Industries Wastewater using Electro-Coagulation and Chemical Coagulation
The objective of the present study was to investigate experimentally the removal of total suspended solid (TSS) and chemical oxygen demand (COD) of wastewater from paper industries by electrocoagulation techniques solely, or with the aid of chemical flocculants. Electro-coagulation experiments were carried out using iron electrodes and either iron sulphate or calcium carbonate as chemical coagulants. A parametric study including the effect of the type of coagulant, initial pH, current density (CD), circulating flow rate, and electro-coagulation time, on the percent removals of TSS, and COD was considered to explore their role in improving the treatment performance. Without the aid of flocculants, electro-coagulation treatment was able to reduce TSS and COD concentrations up to 80%. In particular, electro-coagulation with the aid of iron sulphate or calcium carbonate as flocculants was found to have the highest removal levels that reach values in the range of 90-97%.