Electrokinetic, structural and surface chemical characterizations of both active and porous sublayers of a composite (polyamide/polysulfone) reverse osmosis membrane were carried out by different techniques: (i) electrochemical impedance spectroscopy (EIS) allows both electrical and geometrical characterizations using equivalent circuits as models; (ii) surface chemical composition of the activ...

Entrapment of methane-producing microorganisms between semi-permeable synthetic membranes in a multi-layer membrane bioreactor (MMBR) was studied and compared to the digestion capacity of a free-cell digester, using a hydraulic retention time of one day and organic loading rates (OLR) of 3.08, 6.16, and 8.16 g COD/L·day. The reactor was designed to retain bacterial cells with uprising plug flow...

Changes in the transport parameters and the chemical nature of the surface of composite polyamide/polysulfone membranes due to both aging and treatment with chemical products (HCl, H(3)NO, and NaOH) have been considered. Hydraulic and salt permeability were obtained from water flow and salt diffusion measurements, respectively, and their values seem to indicate a modification in the structural ...

Carboxyls are inherent functional groups of thin-film composite polyamide nanofiltration (NF) membranes, which may play a role in membrane performance and fouling. Their surface presence is attributed to incomplete reaction of acyl chloride monomers during the membrane active layer synthesis by interfacial polymerization. In order to unravel the effect of carboxyl group density on organic fouli...

A novel work was performed for fabrication and modification of composite nanofiltration (NF) membrane by polymerization reaction between polyethyleneimine (PEI) and triphthaloyldechloride (TPC). the main purpose of this work was water treatment. polysulfone was applied as a main polymer of substrate. The result of reaction between PEI and TPC would be formation of polyamide layer on the membran...

this paper reports on preparation of polyamide membrane with addition of silver nanoparticles (agnps). agnps act as antibacterial agents that are less susceptible to membrane’s biofouling by interfacial polymerization (ip) method. agnps was synthesized via green route which has been reported previously. attenuated total reflectance-fourier transform infrared spectroscopy (atr-ftir), field emiss...

This study investigated the effect of Cloisite15A (C15A) organoclay in the substrate layer on the performance of reverse osmosis (RO) membranes. The substrate of the RO membranes was modified using different loading of C15A (ranging from 0.3 - 0.7 wt%) within polysulfone (PSf) substrate and the polyamide (PA) selective layer was formed on the top. Effect of the modified substrate layer on the w...

This paper reports on preparation of polyamide membrane with addition of silver nanoparticles (AgNPs). AgNPs act as antibacterial agents that are less susceptible to membrane’s biofouling by interfacial polymerization (IP) method. AgNPs was synthesized via green route which has been reported previously. Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Field emiss...

We computationally demonstrate that two-dimensional covalent triazine frameworks (CTFs) provide opportunities in water desalination. By varying the chemical building blocks, the pore structure, chemistry, and membrane performance can be designed, leading to two orders of magnitude higher water permeability than polyamide membranes while maintaining excellent ability to reject salts.

the efficiency of diazinon (as insecticides) and nitrate (related to nitrogen fertilizer) removal from contaminated water is investigated through nf membrane technique. the effects of nitrate concentration (40-160 mg/l), diazinon concentration (10-1000 µg/l) and ph (5-9) on the efficiency of a commercial polyamide nanofilter membrane at a constant pressure of (800 kpa) are investigated. the res...