Relating solute properties of contaminants of emerging concern and their rejection by forward osmosis membrane

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>To elucidate the transport of emerging contaminants (CECs) in forward osmosis (FO) membrane process according to their solute properties, the rejections of CECs with various molecular weight, octanol/water partition coefficient (log <I>K</I>ow), and dissociation constant (p<I>K</I> <SUB>a</SUB>) were investigated. Among 12 selected CECs, negatively charged CECs exhibited the highest rejection efficiency than neutral or positively charged CECs due to the electrostatic repulsion between negatively charged CECs and membrane surfaces as well as diffusional hindrance by reversely transported salts from draw stream. The statistical analysis showed that the molecular weight was strongly correlated with the rejection of neutral CECs by size exclusion. Moreover, the correlation between adsorption and log <I>K</I>ow value of neutral CECs was observed due to the hydrophobic interaction. Positively charged CECs exhibited higher adsorption, but lower rejection than the negatively charged CECs due to the locally increased concentration by adsorption, and subsequent migration in FO membrane.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Molecular weight is the most significant factor in the rejection of neutral CECs. </LI> <LI> Rejection of negatively charged CECs is highest due to the electrostatic repulsion. </LI> <LI> Hydrophobicity of CECs is strongly correlated with the adsorption. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>