STUDY ON THE CHARACTERIZATION OF NITROGEN-FIXING BACTERIAL COMMUNITY IN ACTIVATED SLUDGE AND EFFECTS OF RATIO C:N:P ON REMOVAL OF AMMONIA FROM WASTEWATER TREATMENT PLANT

Abstract

Many groups of microorganisms in nature are able to convert nitrogen compounds in wastewater into non-toxic compounds to the environment. It is necessary to exactly determine the bacterial community that posed abilities to remove nitrogen in activated sludge and the effect of the C:N:P ratio to efficiently convert ammonia of the bacterial community. This study was aimedto investigate the bacterial community which can treat nitrogen in the sludge samples by the DGGE method and investigated the effect of the relationship between COD, N-NH4+, and P -PO43- on the formation and oxidation ability of bacteria in activated sludge. This research results show that the bacteria community in the sludge sample from the domestic wastewater treatment system is highly diverse, including the presence of two bacteria capable of converting ammonia including Nitrosomonas sp and Anammox. A ratio of C:N:P of 100:15:1 yielded the highest ammonia removal efficiency for 89.5% in 4 experimental periods.
Keywords: Ammonium, domestic wastewater, DGGE method, nitrogen treats bacteria.