Biofiltetration of Nitrogen Oxides by Immobilized Nitrifying Bacteria Cells

The biofilter packed with immobilized nitrifying bacteria cells (INBC) could be used to removal of nitrogen oxides (NO_x)in low concentration. Nitrifying bacteria were immobilized using sodium alginate and polyvinyl alcohol as entrapped materials. The experimental results showed that NO_x removal efficiency achieved 80.8%; the optimal pH, sprinkling amount and empty bed residence time (EBRT) are 7.3, 0.0906 l/h and 29.3 s, respectively. Nitrogen oxides (NO_x)biodegradation reaction rate follows enzymatic catalytic kinetics. The use of the immobilization microorganism technique proves to be an efficient way to achieve NO_x removal.