Treatment of starch wastewater using UASB reactor with hydraulic circulation and biomass screen

Hydraulic circulation system and biomass screen plate were used to modify a labortary-scale UASB for higher upflow velocity and biomass. The effects of influent concentration, hydraulic retention time, organic volume loading rate and upflow velocity on removal of organic matter from starch wastewater were investigated. The results revealed that biomass screen and hydraulic circulation system accelerated the growth of the anaerobic granular sludge; the modified UASB reactor was successfully started after 30 days operation, COD removal rate reached to 72.2%; the COD removal of starch wastewater increased to 80.2% when the organic volume loading rate is 3.59 kg COD/(m3 d) at reactor operation 48 days; hydraulic retention time of the reactor should be maintained over 20 hours.