Fig. (1) shows the schematic diagram of the electrocoagulation system. In an 800-mL beaker, the calculated volume of the standard zinc or copper stock solution was placed together with deionized water to make 500 mL of the working solution of (10-50 mg.L^-1) initial concentration. Two electrodes were made from commercially available steel slabs with dimensions of 3x50x140 mm. The electrodes were suspended and fixed in place with the aid of a perplex bar with rectangular holes of the dimensions of the steel slabs and placed on the beaker lid. Clamps were employed to ensure electrical contact with the power supplier. Almost 5.5-cm of the electrode length was dipped in the working solution. This made a working area of 27.5 cm².