Performance Evaluation of a Pilot-scale Microbubble-aerated Biofilm Reactor

Abstract

A pilot-scale microbubble-aerated biofilm reactor was operated to treat campus domestic wastewater and its performance was evaluated and compared with conventional biological treatment processes. The results indicated that when the raw campus domestic wastewater was treated in the pilot system, the average COD removal efficiency and loading rate removed were 57.0% and 2.68 kg·(m3·d)-1; the average ammonia nitrogen removal efficiency and loading rate removed were 17.4% and 0.17 kg·(m3·d)-1; the average total nitrogen (TN) removal efficiency and loading rate removed were 15.8% and 0.21 kg·(m3·d)-1; and the average oxygen utilization efficiency reached 100%. When the effluent of biological contact oxidation tank with poor biodegradability was treated in the pilot system, the average COD removal efficiency and loading rate removed were 46.0% and 1.53 kg·(m3·d)-1; the average ammonia nitrogen removal efficiency and loading rate removed were 17.1% and 0.32 kg·(m3·d)-1; the average total nitrogen (TN) removal efficiency and loading rate removed were 14.1% and 0.28 kg·(m3·d)-1; and the average oxygen utilization efficiency was higher than 50%. Furthermore, the contaminant removal performance of the pilot system was much more efficient than conventional biological contact oxidation tank and biological aeration filter tank with the same influent quality, since oxygen transfer and oxygen utilization could be enhanced by microbubble aeration.