Hydrodynamic performance of a hybrid anaerobic baffled reactor (HABR): effects of number of chambers, hydraulic retention time, and influent temperature

Hydrodynamic performance of a biological reactor is an important design concern since it directly affects the treatment efficiency. In this research, a hybrid anaerobic baffled reactor (HABR) was proposed with improved design concepts and principles. The HABR consisted of a front sedimentation chamber, four regular baffled chambers followed by two floated filter media chambers. The effects of operating variables 5–20 hr hydraulic retention time (HRT) and 10–40 °C of influent temperature, as well as their interactive effects, on the hydrodynamic behaviour were investigated by residence time distributions study and response surface methodology. The study suggests that the hydrodynamic performance is greatly influenced by the number of chambers in the reactor rather than HRT and influent temperature. The influence of HRT and feed temperature were mainly observed on the front chambers (1–4) rather than rear chambers (5–7). The optimum reactor performance – low dead space (<10%), excellent hydraulic efficiency (>0.75), and intermediate mixing pattern (Peclet number > 10) – were achieved using the proposed HABR with more than five chambers.