Influence of the Solution pH on Adsorption and Rejection of Race Organic Contaminants from Wastewater by a Nanofiltration Membrane

This study investigated the influence of the feed solution pH on the adsorption and rejection of the trace organic contaminants by a loose nanofiltration membrane NF270. The compounds examined were tested using a cross flow NF/RO cell membrane filtration system for 24 hours under three different pH conditions (4.7, 7 and 11). The feed solution pH effected considerably on the hydrophobicity, charge and the adsorption of dissociable organic compounds and therefore it affected the rejection efficiency of these compounds. Experimental results showed that most of the hydrophobic trace organic contaminants significantly adsorbed onto the membrane, whereas hydrophilic trace organic contaminants less adsorbed compared with hydrophobic compounds at the experimental conditions. Results reported in this study also indicated that thehydrophilic compounds exhibited better rejection values compared to hydrophobic compounds. The rejection efficiency of all these compounds was different depending on the feed solution pH as well as the physicochemical properties of each compound.

Keywords:

Nanofiltration (NF) , Trace organic contaminants (TrOCs) , Adsorption , Rejection efficiency