Anaerobic treatment of phenol in a two-stage anaerobic reactor: a renewable source of energy

This work was selected in a national contest (UK) for the event SET FOR BRITAIN at the House of Commons. Presentations in 2004 by younger engineers at the House of Commons Anaerobic digestion converts organic matter in wastewater to biogas (fuel), and it also produces sludge (fertiliser). However, biogas production can be inhibited by phenolic compounds in wastewater. Phenol is an intermediate product of the anaerobic biodegradation of protocatechuic, 4-Hydroxybenzoic acid, tyrosol, caffeic acid, catechol and gallic acid. The aim is to degrade phenol in a two-stage anaerobic digester operating at 35 0C and 101 KPa. The reactor design separates acidogenic bacteria and methanogenic bacteria to improve the biodegradation efficiency and methane production Methane production was 3 times higher than the CO2 production at a concentration of 67%; 99.2% of phenol was degraded by the two phase anaerobic digester; Phenol is highly degraded by methanogenic bacteria but not by acidogenic bacteria; Biomass concentration was not affected by the addition of phenol.