CHARACTERISTICS OF METALLIC TOXICITY-RESISTANCE BETWEEN BED AND BLANKET SLUDGES IN UASB SYSTEMS

摘要

This study was undertaken to compare the toxicity-resistance of upflow anaerobic sludge blanket (UASB) systems' bed and blanket sludges to heavy metals (cadmium, chromium, copper, nickel. lead and zinc). Experiments were conducted by serum vial assays. The results indicate that total volatile fatty acids (VFA) production and degradation activities decreased with an increasing metal concentration for both sludges. The metallic toxicity-resistance of UASB biogranules was related to zones of sludge, kinds of heavy metal, types of individual VFA, and phases and hydraulic retention time (HRT) of an UASB system. Acidogenic and conventional bed sludges were more resistant to the above noted heavy metals than blanket sludges. For VFA degradation, the toxicity-resistance of both bed and blanket sludges at HRT 2 days was higher than those at HRT 1 day.