Mechanism of degradation of wool wax in the anaerobic treatment of woolscouring wastewater

Abstract

Results of the anaerobic digestion of a woolscouring wastewater treatment and some considerations about the anaerobic degradation mechanisms of wool wax, are presented. A 57 litre anaerobic baffled reactor (ABR) was operated with woolscouring effluent. When organic load varied from 3 to 5 kg COD/m 3 d, COD and grease removal ranged from 40 to 55% and 50 to 65%, respectively. With centrifuged effluent, COD removal was 45% to 60%. A 300 m 3 ABR was built and operated during two years based on the previous laboratory results. COD removal was between 45% to 18% with organic load of 3 to 10 kg COD/m 3 d. With centrifuged effluent, COD efficiencies ranged between 72% and 47%. No inhibition by long chain fatty acids was observed. Considering the results of grease content determination and TLC analysis in both reactors, it could be assumed that wool wax is hydrolyzed forming sterols and free fatty acids and that free fatty acids are degraded while sterols are accumulated in the sludge.