High rate anaerobic digestion of a petrochemical wastewater using biomass support particles

Anaerobic digestion of wastewater from a dimethyl terephthalate plant was studied in continuously stirred tank reactors with plastic net biomass support particles (BSP) at a level of 20% (v/v). The experimental results showed that the BSP system could treat the wastewater at a hydraulic retention time as low as 1.5 d, organic loading as high as 20 kg COD/m(3)/d and at acidic feed pH as low as 4.5 with 95% COD reduction and biogas production of about 8 l/l/d, while the control system without support particles could not treat the wastewater above a 5-d hydraulic retention time, 5 kg COD/m(3)/d organic loading and a feed pH of 6.0. Thus, augmentation of BSP upgraded the performance of the conventional suspended growth system to an equivalent level to advanced reactors.