Effectiveness evaluation of a flat smectite membrane for wastewaters purification: Characterization, cost and energy estimation

This paper investigates the assessment of a smectite flat microfiltration membrane. X-ray fluorescence, X-ray diffraction, thermogravimetric analysis and differential thermal techniques were utilized for the raw powder characterization. The flat membrane was elaborated by a uniaxial pressing method and sintered at a low temperature of 800 degrees C. This membrane presents a very low shrinkage (<= 2.5%), a good mechanical strength of 25 MPa and a good chemical resistance in acidic and basic media. Additionally, the surface contact angle of 61.3 degrees indicates a relatively low hydrophilic character. This property was evaluated by the low water permeability value of 121 L.h-1.m(-2).bar(-1) despite the high average pore diameter of 1.66 mu m found for this microfiltration membrane. Its use in the treatment of three different effluents at a pressure of 2 bar, Methylene Bleu (MB) dye solution, reel textile effluent and oily wastewater, shows stabilized permeate fluxes of 30.2 L.h(-1).m(-2), 42.3 L.h(-1).m(-2 )and 47 L.h(-1).m(-2) respectively. The elaborated membrane exhibited high COD removal (> 93%) and almost total retention in turbidity, color and oil. The energy consumption and the membrane cost were estimated at 2.47 kJ.L(-1 )and 3.357 $.m(-2). All these values demonstrate the competitiveness of this new membrane.