Effect of Coagulant Agents on Oily Wastewater Treatment Performance Using Mullite Ceramic MF Membranes: Experimental and Modeling Studies

In this paper, fouling mechanisms of mullite ceramic membranes for treatment of oily wastewaters in hybrid coagulation-microfiltration (MF) process presented. Hermia's models for cross flow filtration were used to investigate the fouling mechanisms of membranes with various coagulating chemicals concentrations. Four coagulating chemicals (FeCl2·4H2O, FeSO4·7H2O, AlCl3·6H2O and Al2(SO4)3·18H2O) plus Ca(OH)2 of the same concentration were evaluated in the coagulation-MF hybrid process with different concentrations (0, 50 mg·L−1, 100 mg·L−1 and 200 mg·L−1). To determine whether the data agree with models under consideration, the coefficients of determination (R2) of all models were compared with one another. In addition, average prediction errors of models were calculated. The results showed that cake filtration model can be applied for prediction of permeation flux decline for MF and coagulation-(MF) hybrid process with the best average error equal to 0.09%. Results indicated that pore blocking behavior changes as time of filtration increases, and one model cannot predict pore blocking behavior in all filtration time with very good precision.