Interactions of Factors for Effluent Quality in Membrane Bioreactor

Abstract

A new-type membrane module was designed for this project. The permanent hydrophilic macromolecular polymer was adopted as membrane material in the membrane bioreactor (MBR). This MBR combined structural advantages of both hollow fiber membranes and flat sheet membranes. These advantages were large membrane flux, no aeration blind area, and extremly high loading density to allow backflushing. The membrane does not break easily. It is able to swing freely in the water under aeration to reduce membrane fouling. The experimental design was chosen to estimate the influence of several variables. The dyed wastewater was disposed as delegate of refractory industrial effluent with batch operation in this work. The four variables were influent loading, duration of effluent, duration of anoxia and duration of aeration. Then the influence of interaction of factors was studied on the condition that removal rates of COD, TN and membrane flux were considered as response variables. The results showed that influent loading was the most obvious factor affecting the removal rate of COD, and duration of anoxia had the most obvious impact on the removal rate of TN. The removal rate of COD and TN were 94.3% and 81.9%, respectively. The other two factors were more effective for the membrane flux.

Keywords: membrane bioreactor, factorial design, interaction, dyeing wastewater