Removal of natural organic matter by ultrafiltration: Characterisation, fouling and cleaning

Organic matter in natural brown water as well as humic acids from a commerc ial sample were characterised by ultraviolet-visible light-spectroscopy and used in ultrafiltration studies. During ultrafiltration the pure water flu x and the operational flux were measured continuously to determine the degr ee of membrane fouling. The natural organic matter and commercial humic aci d concentrations of the feed and permeate solutions were determined spectro photometrically. These variables were used in conjunction with conventional flux measurements, to determine the colour-removal efficiency of ultrafilt ration as well as the degree of foulant adsorption onto the membranes. Foul ed membranes were cleaned with alkaline chemical agents normally used to ex tract natural organic matter from soil samples. The cleaning efficiency and the effect of cleaning solutions on the membrane selectivity were studied. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All righ ts reserved.