Field study of moving bed biofilm reactor technology for post-treatment of wastewater lagoon effluent at 1°C

Abstract

The goal of this study was to investigate the potential use of moving bed biofilm reactor (MBBR) systems as ammonia removal post-treatment units for wastewater (WW) treatment lagoons that demonstrate large temperature changes throughout their operational year (1−20°C). The study was carried out over a six-month period using laboratory-scale MBBR reactors fed with incoming effluent from a full-scale lagoon. The study shows that significant average ammonia removal rates of 0.26 and 0.11 kg N/m3·d were achieved at 20°C and 1°C. The increase in the ammonia removal rates with increasing temperature from 1°C to 20°C showed a strong correlation to an applied temperature correction coefficient model. No significant accumulation of effluent nitrite was observed at 1°C or after being fed with synthetic wastewater (SWW); indicating that cold temperatures and transitions from real WW to SWW did not stress the nitrifiers. Furthermore, the study demonstrates that changes in temperature or changes from real WW to SWW do not affect the mass of biofilm attached per MBBR carrier. Hence, based on the results of this study, it is concluded that MBBR is a promising technology for post-treatment ammonia removal of WW lagoon effluent.