ELECTROPHOTOCATALYTIC PROCESS OPTIMIZATION FOR REMOVING FORMALDEHYDE BY TAGUCHI MODEL

Contamination of industrial wastewater with formaldehyde as the priority pollutant is the most serious environmental problem in several countries worldwide. Discharging of industrial effluent with formaldehyde concentration of 100-1000 mg/l in to any natural water is considered as toxic substance to human beings. The goal of this applied - analytical research is to investigate of formaldehyde removal from urban drinking water by batch electrophotocatalytic (EPC) reactor with using zinc oxide (ZnO) nanoparticles immobilized on zinc (Zn) sheet-copper electrode, and lamp emitting dynode (LED) ultraviolet-A (UV-A) lamp. The studied variables are pH (4-10), the formaldehyde concentration (100-300 mg/L), the lamp intensity (360-600 mW / cm2), radiation time (7.5-30 min), the distance between lamp and electrode (1.5 cm), layering of zinc oxide nanoparticles (1-3), and current density (3-9 mW/ cm2). The results show the correlation between removal of formaldehyde and UV-A lamp intensity, current density, and radiation time. Optimal removal (0 mg/L) is obtained at pH 10, radiation time: 7.5 minutes, 2- layer of ZnO nanoparticles, and current density of 6 mW / cm2. The findings indicate that removal efficiency is increased with increasing current density, radiation time, and lamp intensity

کلیدواژه ها:

Electrophotocatalytic ، Formaldehyde ، Lamp emitting dynode ، Urban drinking water