V.K Kamal - Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, Tehran, Iran, P.O. Box: ۱۴۱۵۵-۶۱۳۵
A Torabian
F Janpour
G Hoshyaripour

Electrocoagulation (EC) process using aluminum electrodes is proposed to remove fluoride from treated industrial wastewater originated from steel industry. Its efficacy is investigated under different conditions. Effects of temperature, pH, voltage, hydraulic retention time (HRT) and number of aluminum plates between anode and cathode plates on removal efficiency are investigated. Experimental results showed that by increasing HRT, removal efficiency increases but after 5 min changes are negligible. Therefore, the total HRT required is only 5 min. The more HRT, the more electrical current is needed in order to achieving constant voltage and temperature in system. In addition, it is found that pH value decreases within first 10 min from 6.91 to 4.6 but it increases up to The influent pH value is found to be a very important variable that affected effective defluoridation be achieved, but also no pH readjustment is needed after treatment. Moreover, increasing number of aluminum plates between anode and cathode plates in bipolar system does not significantly affect fluoride removal.

Electrocoagulation, Fluoride Removal, Treated Industrial Wastewater, Hydraulic Retention Time