Startup of a Pilot-scale Anammox Reactor by Granular Sludge Inoculation for Treatment of Waste Brine from a Natural Gas Plant

摘要

The goal of this study was to develop a startup strategy for a high-rate anaerobic ammonium oxidation (anammox) reactor for treatment of brine water. Waste brine, generated from a production process of natural gas (methane) and iodine in the Southern Kanto gas field, was subject to the anammox startup test. During a startup period, an upflow anaerobic sludge blanket (UASB) anammox reactor with an effective volume of 294 L was continuously fed with waste brine with salinity of 3% and NH/ of 180 mg-N/L mixed with NaNO_2 solution. Inoculation of methanogenic granules as a carrier allowed emergence of anammox reaction. The reactor eventually attained a volumetric nitrogen removal rate (NRR) of 10.7 kg-N/m~3/day on day 209, 1.7 times higher than the hitherto highest NRR for nitrogen stream with comparable salinity. High-throughput sequencing based on 16S rRNA gene amplicons for the granules revealed that Candidatus Scalindua wagneri was successfully enriched, which replaced methanogens mainly present in the inoculum. The doubling time of the enriched anammox bacteria was calculated to be 4.91-5.32 day. This value is shorter than the previously reported value of Ca. Scalindua (14.4 days).