This work presents a novel bioscrubber configuration for the treatment of high ammonia loads at short contact times. The biological reactor was designed to work as a moving-bed biofilm rector (MBBR) increasing biomass retention time. This configuration is still unexplored for the treatment of waste gases. Long-term operation of a lab-scale bioscrubber under different inlet concentrations of ammonia (60-570 ppmv) and a gas contact time of 4 s was performed to study the system operational limits during 250 days. The effect of the dissolved oxygen concentration on the nitrification rate was also evaluated. Under these conditions, a critical elimination capacity (EC) of 250 NH3·m-3·h-1 and a maximum EC of 300 g NH3·m-3·h-1 were obtained. The maximum nitrification rate obtained was 0.5 kg N·m-3·day-1. However, this nitrification rate only was possible to be achieved under partial nitrification. For complete nitrification, the critical nitrification rate was 0.3 kg N·m-3·day-1. These results confirm that bioscrubber coupled to a MBBR is a good alternative to treat high ammonia loads with remarkable advantages, such as the retention of properly biomass concentration without auxiliary equipment.
Keywords: Ammonia; Bioscrubber; Electrical conductivity; High loads; MBBR; Nitrification rates.
© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.