ID Membrane material Zeta potential Water permeability Salt rejection Recovery rate mV Lm-2day-1Kpa-1 (%) (%) NF(LES90) Polyamide -8.6 1.6 90 80 RO(ES10) Polyamide -15.3 1.2 95.5 80

Table 2: Characteristics of NF and RO membranes.