Determine the optimal parameters for biogas production from common reed (Phragmites australis)

A series of batch assays have been conducted to investigate the optimal factors that can be adopted to improve the anaerobic digestion (AD) performance of Phragmites australis (P. australis ) and increase biogas production. The assays were carried out using 125 ml microcosm reactors with a working volume of 80 ml and incubated at mesophilic conditions 37 C. The effect of particle size (10, 5, 2, and < 1 mm) and alkaline pre-treatment of P. australis using various concentrations of sodium hydroxide concentration (0.5, 1, 2, and 4%) on biogas production were examined. Furthermore, the best pre-treatment incubation time (12, 24, 48, 72, 96, and 120 hours) and the optimal inoculum to substrate ratio (ISR: 4:1, 2:1, 1:1, 1:2 and 1:4) were also assessed. The results revealed that the highest biogas production from P. australis was achieved at: particle size < 1 mm; 2% NaOH concentration for pre-treatment; 120 hours treatment incubation time; and ISR of 1:2.