A Rotating Hollow Fiber Module for Fouling Control in Direct Membrane Filtration of Primary Settled Wastewater

Abstract

Direct membrane filtration (DMF) has emerged as an attractive option to treat municipal wastewater; however, this technology suffers from severe membrane fouling. In this paper, a rotating hollow fiber module for enhancing the fouling control is proposed. The experimental study was conducted at lab scale, filtering a primary settled municipal wastewater. The effectiveness of this technology coupled with physicochemical pretreatment was also evaluated. Results showed the existence of a threshold permeate flux (32−36 L/h·m 2 ), below which the shear rates exerted by membrane rotation prevented supramicron size particle deposition, regardless of the application of physicochemical pretreatment, even at low rotational speeds (w = 120 rpm). At higher fluxes (40−48 L/h·m 2 ), the rotational speed had to be increased to 340 rpm to achieve sustainable conditions. Even when applying physicochemical pretreat- ment, the internal residual fouling was found to be the main fouling contribution, probably associated with the submicron particles