Treatment of waste water from distilleries with chitosan

Purification of vinasse-containing water by an anion-exchange process has been described. The biopolymer chitosan has been used as anion-exchanger. Model experiments with different amounts of chitosan and different time of contact between the substrate and the waste water have shown a chitosan concentration 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 demand (COD) of 2800 mg O2 l−1. A laboratory column process of water purification has been realized on the basis of these parameters. The possibility of subsequent biomethanation of adsorbed organic acid anions on the ion exchanger by a direct adding of chitosan to an anaerobic bioreactor before and after preliminary hydrolysis has been demonstrated.