Comparison of the performance of ultrafiltration and nanofiltration membranes for recovery and recycle of tannins in the leather industry

ESTELA ROMERO DÓNDIZ; JORGE E. ALMAZÁN; VERÓNICA B. RAJAL; ELZA CASTRO VIDAURRE

JOURNAL OF CLEANER PRODUCTION

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2016 vol. 135 p. 71 - 79

0959-6526

The tanning industries are characterized by generating large volumes of wastewater. The largest volumeof effluents comes from the tanning stage and has a high concentration of tannins and a low ratio tannin/non-tannin (T/NT). Membrane processes are appropriate technologies for treating these effluents. Theaim of this study was to evaluate the performance of polymeric membranes in the treatment ofexhausted vegetable tannin liquor from a tanning industry for its reuse. Different ultrafiltration (UF) andnanofiltration (NF) membranes were tested. Permeate flux decline, fouling resistances, fouling index,rejection for tannin (T) and non-tannin (NT) and increasing of the T/NT ratio in the retentate stream wereevaluated. NF membranes had better characteristics than those of UF. The MPF-34 membrane showedthe best separation properties with an increasing of the T/NT ratio from 1.68 to 1.80, for a volumereduction factor of 1.04. DK presented the best permeation properties and the lowest fouling, with anaverage permeate flux of 17.17 L/(m2 h) and a fouling index (If) of 27.3%. The results were promising, sothis clean technology could be implemented to minimize the negative environmental impact caused bytanning industry.