Effects of Hydraulic Conditions on Effluent Quality, Flux Behavior, and Energy Consumption in a Shear-Enhanced Membrane Filtration Using Box-Behnken Response Surface Methodology

Abstract

A systematic study has been carried out to get insight into the effect of hydraulic conditions (feed flow rate (Q), transmembrane pressure (TMP), and rotating speed (N)) on the treatment of dairy wastewater with shear-enhanced membrane flirtation using Box-Behnken response surface methodology (BBRSM). Performances of three types of ultrafiltration (UF) membrane (UH005P, UH030P, and PES050) were compared to choose the optimal membrane. A 1.5 h test was conducted on the analysis of kinetics of permeate flux decline under various hydraulic conditions. With the help of the BBRSM method, the influence and interactions of three hydraulic factors were investigated and regression models were built, while data on effluent quality, flux behavior, and energy consumption as the response values were collected. The results showed that TMP, rotating speed, and their interaction effects could improve significantly effluent quality and flux behavior, reduce several irreversible and total filtration resistancess and greatly decrease energy consumption. The optimal hydraulic conditions obtained by BBRSM were as follows: Q = 75.81 L/h, TMP = 7 bar, and N = 2250 rpm. Under these conditions, the best effluent quality, optimal flux behavior, and minimal energy consumption have been observed.