INFLUENCE OF WATER-CONTENT ON DEGRADATION RATES FOR ETHANOL IN BIOFILTRATION

Treatment of ethanol vapor in a peat biofilter with various initial wa ter contents (70%, 59%, 49%, and 35%) was studied. For water contents ranging from 49% to 70%, elimination rapacity was about 30 g/m(3)/h. F or a water content of 35%, elimination capacity decreased to 4 g/m(3)/ h A low mean CO2,yield coefficient (0.35 g CO2,produced per g ethanol consumed) was found for all of the initial water contents. The value w as only 20% of the yield coefficient (1.91 g/g) predicted by stoichiom etry. When the packing material was dried from 70% to 59% water conten t during the biofiltration process, elimination capacity dropped from 27 g/m(3)/h to 4 g/m(3)/h. After 24 hours of drying, the biofiltration experiment was restarted and run for two more weeks. During this peri od, the biofilter did not recover. At 59% water content, the rate of w ater evaporation was estimated at 59.6 g/m(3)/h. A simplified mass bal ance permitted calculation of the biological water production rate, ap proximately 22.1 g/m(3)/h.