Research And Application Of Membrane Separation Technology In Treating Wool Scouring Wastewater

Wool scouring wastewater is a kind of high concentration organic wastewater. It usually is brown, cloudy, and it contains lots of impurity such as lanolin, cleaning agent, bedload and so on. CODCr is 4.0×10~4~ 6.0×10~4mg/ L, BOD5 1.0×10~4 ~ 1.5×10~4 mg/ L, cleaning agent is 100 ~ 500 mg/ L, and pH is 8 ~ 11. After studying detailedly all kinds of methods for treating wool scouring wastewater at home and aboard, hollow fiber ultrafiltration was adopted to treat the wastewater through laboratory and middle experiments in this paper, membrane material is PES, the interior diameter and MWCO of the hollow fiber ultrafiltration is 1.4mm and 4.0×10~4 Dolton respective. Retention property of CODCr, lanolin and turbidity and effect of transmembrane pressure, feed temperature ,feed velocity and geometry dimension on membrane flux and membrane fouling were reviewed in the ultrafiltration, and Dean vortex was used to improve membrane flux and to reduce membrane fouling; PAC and PAM as for composite flocculation was applied for treating ultrafiltration retentate, the effect of flocculation concentration, rotate speed, and temperature on flocculation effect was researched and optimized with orthogonal experiment, at the same time, the process of extracting lanolin was reviewed and optimized with orthogonal experiment; Nanofiltration equipment was adopted to farther attempt to treat ultrafiltration permeate based on the permeate recycled to scour wool through middle experiment. The effect of concentration process on membrane flux and the retention properties of CODCr and ionic strength were reviewed. According to the results of laboratory and middle experiments, 40 ultrafiltration modules, which isΦ160×1260, were adopted to treat 200t/d wool scouring wastewater. The engineering practice result as follows: the elimination coefficient of CODCr was as to 90.4% ~ 91.1%, the retention of lanolin was as to 91% ~ 91.7%, and the elimination coefficient of turbidity was as to 99.2% ~ 99.3%. The treatment power could be satisfied. Water, heat energy and cleaning agent were saved. Lanolin was extracted, so it increased economy income, the number could be as to 1.0×10~6RBM/a.