Applied Microbiology

Biography

Biography: Hui-Ping Chuang

Abstract

Cyclic Low Energy Ammonium Removal (Cleargreen) System is one type of the energy-saving de-ammonification system. A pilot scale Cleargreen system, with a feeding rate of 6.9 m3/day effluent water from a secondary wastewater treatment, has been tested in South Australia for 2 years. During a 450-day operation, the system gave a high ammonia removal of 80-85% with nitrite up to 150 mg N/L in the effluent. During the operation, 30 samples were taken for analysis of 454 pyrosequencing and quantitative PCR (qPCR). Analysis of 454 pyrosequencing showed that four nitrogen-related groups, family Nitrosomonadaceae, Nitrospiraceae, Brocadiaceae and Rhodobacteraceae, were detected, although all of them werebelow 4% of total bacterial population. Furthermore, the decrease of Comamonadace population was observed with the increasing of NH4+-N removal; while Brocadiaceae population was found to increase as NH4+-N removal was higher than 50%. qPCR results indicated that Nitrospira and other denitrifying groups containing nirS gene dominated in the system with the abundance of 5×1010 cell/mgVSS. Two ammonia-oxidizing bacteria and archaea groups, Nitrobacter and anammox were detected at 103 - 106 cell/mg VSS. Ammonia-oxidizing archaea increased with increasing NH4+-N removal when NH4+-N oxidation ratio was below 50%, while anammox bacteria group positively related withthe removal of ammonia and total nitrogen removal. For microbial diversity of targeted nitrogen-related microbes, results from both 454 pyrosequencing and qPCR methods indicated that anammox bacteria could be enriched in the Cleargreen system, accompanying with the vicissitudes of other nitrogen-related microbes.