Degradation of PTA wastewater in a internal loop three phase anaerobic fluidized bed reactor

Using lava rock as carrier, the anaerobic bioreactor is set up with the method of aerobic precoating treatment of carrier and rapid clean up of sludge. The start-up phase is 47 days. In the operation period, when the COD of PTA wastewater is (4752.3±41.2) mg/L, the HRT of the AFBR is (17.3±1.2) hours and the organic loading rate (OLR) is 6.5 kgCOD/(m³·d), the COD removal rate and TA removal rate are (64.0±4.4)% and (65.1±1.3)%, respectively. The biomass on the carrier is (13.3±0.2) mg VSS/g carrier. Analyzed by scanning electron microscope(SEM), the interior pores of the lava rock is hermetic and the anaerobes is mainly grown in the pores of exterior surface. The observed sludge yield (Yobs) is 0.057 g VSS/g removal COD and the carrier substrate utilization is 0.83 g removal COD/(g VSSd).