Influence of bio-attapulgite on dissolved organic matters (DOM) removal in dynamic membrane reactor

Abstract

Membrane bioreactor (MBR) fouling is influenced not only by the concentration of dissolved organic matters (DOM) but by their characteristics. This paper examined the effect of bio-attapulgite on DOM removal mechanisms in a dynamic membrane bioreactor (DMBR). Results indicated the dissolved organic matters (DOM) in the attapulgite-added DMBR system decomposed obviously faster than in the DMBR system. Hence, the attapulgite-added DMBR system had a higher DOM removal rate in term of DOC and UV 254 concentration. Due to the hybrid effect of adsorption and co-precipitation on dissolved organic matters after the addition of attapulgite, the positive effects of attapulgite adjunction allowed mitigation of membrane fouling. The characteristics of DOM in the two bioreactors considerably differed as excitation-emission matrix (EEM) fluorescence spectroscopy revealed. The molecular weight distribution analyzed by gel permeation chromatography (GPC) was affected by attapulgite-addition. The microorganisms and their extracellular polymer substances could bind attapulgite particles tightly to form bio-attapulgite particles. The attapulgite-added DMBR system could more effectively remove the hydrophilic fraction of dissolved organic matters than the DMBR system.