Indian Journal of Science and Technology

Abstract

This paper deals with removal of finely dispersed oil from oily-effluents of different fields of North Gujarat, India by Electroflotation method. Experiments were carried in electrolytic cell equipped with a set of perforated aluminium electrodes & variable DC voltage using batchwise process. The parameters investigated are voltage, salinity, pH, oil concentration and flotation time. The batch experiment has been conducted to optimize electrical input & its duration in the effluent. The optimum conditions for all the three fields studied are 5.0 V voltage, 0.4 to 0.9 A current and 40 min flotation time, the corresponding energy consumption is in the range of 0.44 to 0.59 kWh/m3 . Also on decreasing the pH to 4.54, the percentage oil removal decreases and on increasing the pH to 9.54, the percentage oil removal increases. The oil removal is 90.7% at 4.54 pH and 97.9% at 9.5 pH in 40 min flotation time for 145mg/l of initial oil concentration. It is observed that, as the salinity increases the amount of oil removal decreases and the period of treatment and power consumption increases.
Keywords: Oil-in-water emulsion, Effluent , Oily effluent treatment, Electroflotation; Oil removal