Application of the Spiegler–Kedem–Kachalsky model to the removal of 4-chlorophenol by different nanofiltration membranes

Positively-charged nanofiltration membrane formed by quaternization and cross-linking of blend PVC/P(DMA-co-MMA) precursors

“…9(a), the permeation flux for optimized NF membrane of M4-XDC(0.8%) performed linearly dependence on loaded TMP during a TMP rise-drop cycle of 0.1-0.5 MPa. This was in accordance with the typical Spiegler-Kedem-Kachalsky (SKK) model [37]. This indicated that the PVC/P(DMA-co-MMA) NF membrane was pressure-proof.…”

Rejection prediction of isopropylantipyrine and antipyrine by nanofiltration membranes based on the Spiegler–Kedem–Katchalsky model

“…(3), which contains two parts, the first term represents diffusion and the second term represents convection [30]. In general, convection occurs because of the pressure gradient on both sides of the membrane, and the concentration gradient leads to diffusion [1,31]. However, solvent transport is due to the pressure gradient across the membrane, and solute transport is due to the concentration gradient and convective coupling to the volume flow.…”

Application of low-pressure reverse osmosis for effective recovery of bisphenol A from aqueous wastes

“…L p is pure water permeability, C s is the logarithmic averaged of solute concentration between feed and permeate sides, C m is the solute concentration at the membrane surface, and C p is the solute concentration in permeate side [35].…”

“…According to the Spiegler-Kedem-Katchalsky model, pressure is the driving force for solvent transport and concentration is the driving force for solute transport. According to this model, the solute flux is lower pressure dependent than water flux [35]. Thus, it is reasonable that the water flux (J w ) is increased directly with pressure.…”

“…This behavior was observed at all of feed concentrations. Polyamide membranes at alkaline solutions is hydrolyzed from free carboxylic acid groups, so the membrane ionization is occurred at pH values above 7 and makes the membrane surface negatively charged [35]. At pH 8, BPA molecule is ionized to bisphenolate with one negative charge.…”