(258c) Hydraulic Retention Time and Temperature Impacts on Biogas Production in Expanded Granular Sludge Bed Reactor
An expanded granular sludge bed reactor, updated from the up-flow anaerobic sludge reactor, has been used to investigate the effect of hydraulic retention time and temperature on biogas production rate and methane composition of the biogas. The process consists of a two-stage reactor with a pre-acidification stage where hydrolysis and acidogenesis steps occur followed by the main reactor where the acetogenesis and methanogenesis steps occur.
Equivalent specific values of organic loading rates for industrial waste water with different COD levels (20, 30 and 40 g COD/l) have been used. The biogas production increases with decreasing hydraulic retention time (i.e. 24 gallons/ day) and decreases when biogas production is inhibited by lower residence times below that required to complete degradation of the wastes and eventually affect the activity of the overall biodigestion process.
Methane composition and COD removal efficiency are (65-78%) and (90-96.5 %) respectively. A detailed analysis has been conducted for the process effluent using a Benchtop Spectrophotometer to monitor the process stability.