POTENTIAL FOR THE PSYCHROPHILIC ANAEROBIC TREATMENT OF SWINE MANURE USING A SEQUENCING BATCH REACTOR

The feasibility of psychrophilic anaerobic digestion (PAD) in intermit tently fed sequencing batch reactors (SBR) was investigated during the start-up run of an ongoing laboratory study. The start-up run results indicated that PAD in SBRs was efficient in stabilizing and deodorizi ng swine manure slurry. The digester effluents had little odour when c ompared to the raw manure. Total chemical oxygen demand (COD) was redu ced by 58 to 73% and soluble COD (SCOD) by 85 to 96%. Methane producti on varied from 0.30 to 0.66 L CH4/g volatile solids added and methane concentration in the biogas ranged from 50 to 80%. The biogas producti on rate continued to increase even when concentrations of acetic acid and ammonia nitrogen were as high as 5500 mg/L and 3700 mg/L, respecti vely.