Nitrogen removal from an AAO pilot plant with nitrifier bioaugmentation after seasonal deterioration

Abstract

A B S T R A C TNitrogen removal was studied in a pilot-scale anaerobic-anoxic-oxic (AAO) system that was bioaugmented with nitrifiers cultivated from reject water after seasonal deterioration. The process of nitrogen removal was evaluated with increased temperature from 11 to 24˚C. Nitrification efficiency rapidly recovered with increased temperature from 12 to 15˚C, and the nitrification rates at 18˚C were 3.1 times that at 12˚C, higher than the report in ASM1. Bioaugmentation may shorten the recovery time of nitrification activity in WWTPs. The nitrification activity and microbial ecology of the full-scale system operating parallel with the pilot-scale were correspondingly studied, and similar community structures were observed. Despite the lower nitrifying bacteria count, the nitrification activity of the bioaugmented pilot-scale plant was still higher than that of the full-scale one.

Enhanced Nitrogen Removal in a Pilot-Scale Anoxic/Aerobic (A/O) Process Coupling PE Carrier and Nitrifying Bacteria PE Carrier: Performance and Microbial Shift

“…Despite the aforementioned advantages of IFAS systems, there were limited studies investigating the possibility of enriching nitrifying bacteria on a suspended carrier by culturing it with anaerobic digestion liquor. In order to shorten the recovery time of nitrification activity in WWTPs, some studies have investigated the feasibility of enhancing nitrogen removal in a pilot-scale A 2 O system by adding nitrifiers cultured from anaerobic digestion liquor [25]. However, the bioaugmentation effect of nitrifiers gradually disappeared with the long-term operation of BNR systems [26,27].…”