Biosurfactant Based Micellar Enhanced Ultrafiltration for Separation of Organic Compounds and Heavy Metal Ions from Aqueous Solution

Abstract

MEUF experiments were conducted in dead-end stirred cell under batch concentration mode according to experimental design for all the three systems. Response surface methodology (RSM) was used to optimize the feed conditions of MEUF by the simultaneous maximization of the permeate flux and pollutant (single/binary) rejection. Eigenvalue analysis was performed to evaluate the nature of optimal condition. The second order polynomial regression model gave a satisfactory explanation of most of the experimental data. Analysis of variance (ANOVA) was performed for each response to evaluate the effect of the independent variables and the possible interactions between them, and also to assess the statistical importance of the regression model. The suitability of the model for predicting the optimum response value was checked by confirmative test. The effects of various feed parameters on the permeate flux and pollutant removal efficiency were illustrated. For all the three systems, the performance of MEUF process was assessed through estimation of the distribution coefficient, RHL vesicle loading and RHL vesicle binding constants for the pollutants. Under the optimal feed conditions, the effects of various hydrodynamic conditions such as transmembrane pressure, stirrer speed/cross flow velocity and feed temperature on permeate flux and solute rejection were studied during dead-end/cross-flow MEUF process. Results of RHL based MEUF process were compared with chemical surfactant (sodium dodecyl sulfate) based MEUF process in terms of pollutant removal efficiency, process throughput and processing cost. Abstract Understanding of underlying mechanisms of membrane fouling and modelling for prediction of permeate flux and solute rejection were very important for the successful application of any MEUF studies. During cross-flow MEUF of aqueous solution of CV, experimental flux data revealed the involvement of more than one type of fouling mechanism and shifting of fouling mechanism