New Electrodes Design for Oily Wastewater Treatment Using Electro-Chemical Techniques

Abstract

Electrocoagulation (EG) is effective in breaking oily water emulsions. New anode design in the EG of oily wastewater lube oil emulsion is investigated. In this study, EG using aluminum sacrificial anode was used for the treatment of oily emulsion. A multi layers 5 discs rotating Al disc with 7 cm in diameter and each layer is 0.5 cm apart is designed to be used as an anode. Variables considered were the disc anode rotational speed (from 250 to 1000 r.p.m), NaCl amount as electrolyte dose (1, 3, 5, 7, 9 g/3litre), pH (ranged from 3 to11), oil emulsion concentration (250 to 1000 ppm). It was found that the percent of oil removal is decreased by the increase of rotating speed (> 750 r.p.m) and NaCl dose (1g/3lit.) while it increase by the increase in pH of the emulsion (>3). The maximum percent removal (79 %) is obtained at pH=9, initial oil concentration = 1000 ppm and r.p.m=750. A comparison of the obtained results were another values of anodes of different shape is held. A treatment of the considered cutting oil is completed at initial concentration of 10 mg Al/g oil, with a slight positive effect of the liquid flow rate. Best results are also obtained with initial pH near 7. Other comparison was carried out with different EG techniques.