Degrading sludge with cellulase complex
Abstract
The ability of indigenous and commercial cellulase complexes to degrade native and pretreated sludge was evaluated. Indigenous enzyme was produced in our laboratory, where as commercial cellulase was purchased from a chemical supplier. Pretreatments included detergent solutions, sodium hydroxide, hydrochloric acid, sulfuric acid, sulfur trioxide, alkaline peroxide and sonification. Glucose production was used to infer degradability. Compared controls (no glucose produced), hydrochloric acid and sodium hydroxide treatment resulted in most degradation. Other treatments were much less effective. The commercial cellulase degraded standards (cellulose) much more rapidly and extensively than indigenous. Although commercial cellulase and either sodium hydroxide or hydrochloric acid treatment increased degradability of sludge considerably above the controls, improvement was much less than expected. Physical appearance of sludges was altered greatly by pretreatment but the implications of this are unclear.