REMOVAL OF HUMIC ACID IN WATER USING MODIFIED COMPOSITE MEMBRANE

Abstract

    Humic acid (HA) is a major organic matter in surface water sources. It can cause foulingphenomena during membrane filtration processes for water purification. In this work, thepossibility for removal of humic acid in water by modified thin film composite membrane(BW30) was investigated. The modification of membrane surface was performed by UVinduced-grafting polymerization technique using poly- ethylene glycol (PEG) for grafting.Membrane surface characteristics were determined through the attenuated total reflection-Fourier transform infrared (FTIR-ATR) spectroscopy and atomic force microscopy (AFM)images, which showed the changes in membrane surface functionality and its morphologyafter graft polymerization. The experimental results indicated that the humic acid can beremoved well by modified composite membrane BW30. The retention of modified membranesgrafted with PEG under appropriate conditions is almost maintained meanwhile its flux ishigher than that of unmodified one. The antifouling property of modified membranes is alsoimproved with the higher flux maintained ratio and the lower irreversible fouling factorsduring filtration.

Keywords: humic acid, surface grafting, poly-ethylene glycol, thin film composite membrane.