HUMIC MEMBRANE FOULANTS IN NATURAL BROWN WATER - CHARACTERIZATION ANDREMOVAL

Organic matter in natural brown water as well as humic acids from a co mmercial sample were characterised by ultraviolet-visible light-spectr oscopy and used in ultrafiltration studies. During ultrafiltration the pure-water flux and the operational flux were measured continuously t o determine the degree of membrane fouling. The natural organic matter and commercial humic acid concentrations of the feed and permeate sol utions were determined spectrophotometrically. These variables were us ed in conjunction with conventional flux measurements, to determine th e colour-removal efficiency of ultrafiltration as well as the degree o f foulant adsorption onto the membranes. By calculating the ratio betw een the light absorbance at 465 and 656 nm, the relative sizes of the molecules in the feed and permeate solutions were monitored. Fouled me mbranes were cleaned with alkaline chemical agents normally used to ex tract natural organic matter from soil samples. The cleaning efficienc y and the effect of cleaning solutions on the membrane selectivity wer e studied.