Electro-kinetic dewatering of oily sludges.
An oily sludge from a rendering facility was treated using electro-kinetic (EK) techniques employing two different experimental designs. The bench scale used vertical electrodes under different operational conditions, i.e. varied electrode spacing at 4, 6 and 8 cm with electric potential of 10, 20 and 30 V, respectively. The highest water removal efficiency (56.3%) at bench scale was achieved at a 4 cm spacing and 30 V. Comparison of the water removal efficiency (51.9%) achieved at the 20 V at 4 cm spacing showed that power consumption at 30 V was 1.5 times larger than that at 20 V, suggesting a further increase of electric potential is unnecessary. The solids content increased from an initial 5 to 11.5 and 14.1% for 20 and 30 V, respectively. The removal of oil and grease (O&G) was not significant at this experimental design. Another larger scale experiment using a pair of horizontal electrodes in a cylinder with 15 cm i.d. was conducted at 60 V at an initial spacing of 22 cm. More than 40.0% of water was removed and a very efficient oil separation from the sludge was achieved indicating the viability of electro-kinetic recovery of oil from industrial sludge.
Yang
Lin
L
Department of Chemical & Biochemical Engineering, The University of Western Ontario, London, Ont., Canada.
Nakhla
George
G
Bassi
Amarjeet
A
D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D005374:Filtration / Q000295:instrumentation / Q000379:methods; D007220:Industrial Waste / Q000517:prevention & control*; D007700:Kinetics; D009821:Oils / Q000302:isolation & purification; D012722:Sewage / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D007220:Industrial Waste; D009821:Oils; D012722:Sewage; D014867:Water