Table 4: Effect of ionic strength on rejection of compounds by the two NF membranes (transmembrane pressure 500 kPa, pH 7.5; initial concentration of compounds 0.5–0.8 mg L−1).

Membrane/ionic strengthFlux (L m−2 h−1)Dimethyl phthalate (%)Diethyl phthalate (%)Acenaphthylene (%)Phenanthrene (%)

NF90
 10 mM34.695.096.091.296.0
 20 mM37.193.095.091.293.1
NF270
 10 mM72.365.875.687.392.5
 20 mM87.325.033.382.488.6