Separating oil from oil-water emulsions by electroflotation technique

The separation of finely dispersed oil from oil-water emulsions was carried out in an electroflotation cell which has a set of electrodes, a lead anode acid stainless steel screen cathode. The effect of operating parameters on the performance of the batch cell was examined. The parameters investigated are electrical current, oil concentration, flotation time and flocculant agent concentrations. A well-fitted empirical correlation represents the change in percentage oil removal with wide range of operating conditions was obtained. The oil separation reached 65% at optimum conditions; 75% in the presence of NaCl (3.5% by wt. of solution); and 92% with the presence of NaCl and at optimum concentration of flocculant agent. Electrical energy consumption varied from 0.5 to 10.6 KWh/m(3) according to experimental conditions. An equation relates the K with I was obtained. The general form of the equation is K = constant (I)(n); where the n values are 0.64 and 0.62 for solutions with and without NaCl, respectively. The previous relation is valid only for current values from 0.3 to 1.2 A. The effect of emulsion flow rate on the separation process was determined on continuous scale.