Removal of Scale Forming Species from Cooling Tower Blowdown Water by Electrocoagulation Using Different Electrodes20191214 78750 1ly32w (original) (raw)

tThis work investigates the effect of electrocoagulation (EC) using Al, Fe, and Zn electrodesfor removing hardness ions and dissolved silica from cooling tower blowdown (CTB) water.The real samples were collected from urea fertilizer factory (Helwan Fertilizer Company),Cairo, Egypt. The effect of operational parameters, such as current density, electrolysis time,inter-electrode distance and stirring rate were studied and evaluated for the maximumefficiency. At the optimum operational conditions, Al-electrode removed the scale formingspecies from CTB water more efficiently than Zn and Fe electrodes. Al, Fe, and Zn electrodesremoved 55.36% and 99.54%, 36.99% and 98.93% as well as 38.63% and 95.62% for the totalhardness and silica ions, respectively. In order to rationalize the removal mechanism, the ECgenerated sludge was characterized by SEM-EDX, XRD, and FTIR. The present investigationinferred that Al-EC generates amorphous nature crystalline and other anode materials (Feand Zn) forms definite crystalline particles. EDX showed the presence of Ca2+, Mg2+, and silicaions in the sludge which proved the removal of these scale species from CTB water. As aconclusion, this study revealed that EC process using Al-electrode is a promising technologyfor the removal of scale forming species from CTB water.