Comparative performance of high rate anaerobic thermophilic technologies treating industrial wastewater

The performance of two high rate technologies, anaerobic filter and fluidized bed at laboratory-scale, for treating distillery wastewater (wine vinasses) at anaerobic thermophilic conditions, have been compared in this study. Two kinds of media, corrugated plastic tubes and open-pore sintered glass pearls (SIRAN) were used as support on reactors. Experimentally, it was confirmed that the maximum organic load rate feed was 32 kg COD m−3 d−1 for the fluidized bed reactor with the porous packing (SIRAN), 23 kg COD m−3 d−1 for the stationary packed bed on SIRAN and 20 kg COD m−3 d−1 for the anaerobic filter on corrugated plastic tubes. Under these conditions, the organic removal efficiency was 81.5, 75 and 50% respectively and the maximum organic removal efficiency was 97, 84 and 75%, respectively. The anaerobic fluidized bed technology is more effective than the anaerobic filter technology due, fundamentally, to this technology favouring the transport of microbial cells from the bulk to the surface and enhancing the contact between the microorganism and substrate phases. In this sense, the stationary packed bed technology is adequate for the treatment of easily biodegradable wastewater or for cases where elevated percentages of COD removal are not required, while the fluidized bed technology is especially suitable for treatment of hazardous wastes with recalcitrant compositions.