Development of a novel deammonification process for cost effective separate centrate and main plant nitrogen removal

Abstract

With an increasing need to reduce nitrogen loads from wastewater discharges, the wastewater industry is developing treatment processes that can effectively remove nitrogen with reduced chemical and energy costs. Technologies for standard deammonification are available for removing nitrogen from ammonia-rich streams produced during sludge dewatering. These processes use partial nitritation coupled with anaerobic ammonia oxidation (Anammox) to simultaneously remove ammonia and nitrite. These technologies use 34% of the air and no supplemental carbon as compared to conventional nitrogen removal processes. However, standard deammonification processes require effective suppression of Nitrite Oxidizing Bacteria (NOB) to be effective, which can require sophisticated operations. The discovery of a Glycerol Acclimated Biomass (GAB) that carries out accelerated denitratation led to the development of a novel deammonification process that produces the required nitrite via partial denitratation. The nitrite and residual ammonia is converted to nitrogen gas via anammox activity. This novel process removes up to 80% of the total nitrogen from centrate without the need for NOB suppression. The process uses 50% less energy and 75% less carbon than conventional BNR processes.