Mitigation of organic fouling on ceramic membranes by selective removal of microbial-oriented organic matters in wastewater effluents

Abstract

The fouling propensity of organic matter categorized by their origins has been investigated during the reuse of tertiary wastewater effluent by a ceramic ultrafiltration membrane with molecular weight cut-off (MWCO) around 1 kDa. Selective removal of organic matter was carried out with three carbon-based adsorbents including granular activated carbon (GAC), expanded graphite (EG), and multi-walled carbon nanotubes (MWNTs). Analysis on the residual organic matter after the adsorption revealed that EG and MWNTs mainly adsorbed microbial-oriented organic matters (MOOMs) such as the soluble microbial products (SMP)-like and aromatic protein (AP)-like organic compounds, while GAC showed non-selective organic removals. At the identical organic loading, feed solution treated by EG and MWNTs exhibited significantly lower fouling propensity than that of the GAC-treated sample. Consequently, the selective removal of MOOMs from tertiary effluents can provide an effective strategy to reduce organic fouling on ceramic membranes.