Biogas Production and Metagenomic Analysis in a New Hybrid Anaerobic Labyrinth-Flow Bioreactor Treating Dairy Wastewater

Increasing worldwide milk manufacturing and dairy processing resulted in producing more effluents, thus effective management of wastewater is now the most important issue. This study used a new design pilot plant-scale hybrid anaerobic labyrinth-flow bioreactor (AL-FB) to increase efficiency biodegradation biogas productivity improve microflora performance. In addition, effluent recirculation was boost treatment wastewater. Metagenomic analyses microbial community were performed. It found that an organic loading rate (OLR) 4.0–8.0 g COD/L·d contributed highest CH4 yield 0.18 ± 0.01–0.23 0.02 L CH4/g COD removed, which corresponded high removal 87.5 2.8–94.1 1.3%. The evenest distribution microorganisms’ phyla determined production. all tested samples, Bacteroidetes Firmicutes abundance highest, Archaea accounted for about 4%. studies showed methane mainly produced acetoclastic methanogenesis; however, higher OLRs favorable enhanced hydrogenotrophic methanogenesis. Effluent overall treatment. Thus, at OLR 10.0 COD/L·d, 89.2 0.4%, production achieved 0.20 0.01 by 25% compared achievements without recirculation.