Affiliations: College of Environmental and Energy Engineering,
Beijing University of Technology, Beijing 100022, China | Department of Chemistry, Fuling Normal University,
Chongqing 408003, China | School of Civil Engineering and Architecture, Zhejiang
University of Technology, Hangzhou 310014, China
Abstract: The principal aim of this paper is to develop an approach to realize
stable biological nitrogen removal via nitrite under normal conditions.
Validation of the new method was established on laboratory-scale experiments
applying the sequencing batch reactor (SBR) activated sludge process to
domestic wastewater with low C/N ratio. The addition of sodium chloride (NaCl)
to influent was established to achieve nitrite build-up. The high nitrite
accumulation, depending on the salinity in influent and the application
duration of salt, was obtained in SBRs treating saline wastewater. The
maintenance results indicated that the real-time SBRs can maintain stable
nitrite accumulation, but conversion from shorter nitrification-denitrification
to full nitrification-denitrification was observed after some operation cycles
in the other SBR with fixed-time control. The presented method is valuable to
offer a solution to realize and to maintain nitrogen removal via nitrite under
normal conditions.
Keywords: nitrite accumulation, salt selective inhibition, real-time control of nitrification, biological nitrogen removal via nitrite, nitrite-oxidizers, ammonium-oxidizers
