Wastewater treatment in a hybrid biological reactor (HBR) : Nitrification characteristics

Objective To investigate the nitrifying characteristics of both suspended- and attached-biomass in a hybrid bioreactor. Methods The hybrid biological reactor was developed by introducing porous ceramic particles into the reactor to provide the surface for biomass attachment. Microorganisms immobilized on the ceramics were observed using scanning electron microscopy (SEM). All chemical analyses were performed in accordance with standard methods. Results The suspended- and attached-biomass had approximately the same nitrification activity. The nitrifying kinetic was independent of the initial biomass concentration, and the attached-biomass had a stronger ability to resist the nitrification inhibitor. Conclusion The attached biomass is superior to suspended-biomass for nitrifying wastewater, especially that containing toxic organic compounds. The hybrid biological reactor consisting of suspended- and attached-biomass is advantageous in such cases. Key words: Attached biomass; Hybrid biological reactor, Nitrification; Suspended biomass; Nitrification inhibitor.