Treatment of waste water from distilleries with chitosan

Purification of vinasse-containing water by an anion-exchange process has b een described. The biopolymer chitosan has been used as anion-exchanger, Mo del experiments with different amounts of Chitosan and different time of co ntact between the substrate and the waste water have shown a chitosan conce ntration of 10 g l(-1) and a contact time of 30 min to be the most suitable for the purification of the model waste water with a chemical oxygen deman d (COD) of 2800 mg O-2 l(-1). A laboratory column process of water purifica tion has been realized on the basis of these parameters. The possibility of subsequent biomethanation of adsorbed organic acid anions on the ion excha nger by a direct adding of chitosan to an anaerobic bioreactor before and a fter preliminary hydrolysis has been demonstrated. (C) 2000 Elsevier Scienc e Ltd. All rights reserved.