Heterogeneity of ammonia-oxidizing community structures in a pilot-scale drinking water biofilter

Drinking water biofilters have been widely used for ammonia removal. Knowledge about the structure of ammonia oxidizing communities can aid in understanding of nitrification process. Terminal restriction fragment length polymorphism (TRFLP) analysis of amoA genes in combination with cloning and sequencing analysis were used to investigate spatial heterogeneity of ammonia oxidizing archaea (AOA) and ammonia oxidizing bacteria (AOB) communities in a pilot-scale granular activated carbon (GAC)-sand dual media filter. The results illustrate the diversity of AOB communities on GAC samples and their changes along the filter depth. Moreover, Nitrosomonas-like microorganisms were the dominant AOB species in GAC samples. However, AOA was not detected in the biofilter. This work could add some new insights into the nitrification in drinking water biofilters. (C) 2012 Elsevier Ltd. All rights reserved.