Abstract:
This research investigated the use of crumb rubber as a media in the Anaerobic Fluidized Bed (AFB) process for treating synthetic wastewater. The synthetic wastewater was prepared from tap water using sucrose as carbon source with sufficient nutrients. High COD concentration about 2,500, 5,000, 7,500, and 10,000 mg/l, which equal to 5, 10, 15, and 20 kg COD/m3-d organic loading rates (OLRs) respectively, were fed into a 12 hr hydraulic retention time AFB reactor. The efficiencies in term of COD removal and biogas production were investigated. For the OLRs 5, 10, 15 and 20 kg COD/m3-d, the average COD removal were 78.38, 94.80, 97.70 and 94.60%, respectively ; whereas the biogas production was approximately 0.60, 0.61, 0.62, and 0.60 l/g.COD removed, respectively. For the organic loading rate of 15 kg COD/m3-day, the result indicated the highest COD removal and biogas production, which percentage of methane in the biogas was 55.30%. Moreover, Fluorescent In Situ Hybridization (FISH) results showed that the quantity of archaea adhered throughout the whole support materials was significantly greater than bacteria. These outcomes are consistent with the result of COD removal efficiencies and biogas production. Moreover, the determination of lipid phosphate concentration and results from SEM (Scanning Electron Microscope) found that the biomass adhesion on the media was higher when OLRs increased from 5 to 20 kg COD/m3-d, which were consistent with the previous results.