Electroflotation of emulsified oil in industrial wastes evaluated with a full factorial design

Abstract - The use of electroflotation in emulsified oil wastes was studied. A rectangular electroflotation cell was designed and constructed in acrylic with stainless steel cathode and DSA ® anode with a nominal composition of Ti/Ru 0.34 Ti 0.66 O 2 . The variables studied in the present work were current density and oil, flocculant and electrolyte (NaCl) concentrations. The experiments were carried out in accordance with 2 4 full factorial experimental designs with two center points. The STATISTICA 5.5 software was used for calculations in order to relate experimental data to a statistical model. The best results, yielded 99.71% oil removal were obtained from 1050ppm of emulsified oil feed. Keywords : Electroflotation; Emulsified oil; Industrial waste water; Factorial design. INTRODUCTION The development of new techniques for treatment of wastewater with high salinity from the petroleum industry has been a challenge due to the increase in production in Brazil. Voluntary or involuntary spilling of oil in different kinds of water is an issue of environmental concern. The high salinity and large volumes normally involved prevent the use of traditional biological processes. Conventional biological processes are there ruled out due to the requirement of large plant and skilled technicians. In the electroflotation process, bubbles are generated by water electrolysis (Chen et al, 2002 and Ben Mansur et al, 2006) to produce hydrogen and oxygen at the cathode and anode respectively. Compared with conventional flotation, electroflotation has many advantages. Firstly, it is characterized by a fast rate of removal pollutant particles. Secondly, it is able to achieve simultaneous flotation and coagulation, with less sludge produced. Thirdly, the electroflotation equipment is very compact and thus suitable for installation where the available space is rather limited. Furthermore, the convenience of dosing