Abstract
Nitrogen removal using a polyethylene (PE) sponge biomass carrier was evaluated in a fixed-bed reactor for nitrogen removal by the anammox process. The fixed-bed reactor was operated continuously for 240 days. T－N removal efficiencies increased from 38 %, 67 %, 72 %, 74 % to 75 % with stepwise increases in volumetric T－N loading rates. A T－N removal rate of 2.8 kg N/m3/day was obtained after 240 days of operation. After 3 months, anammox biomass fully covered the surface of the PE sponge carrier and the color of the material changed from white to red. Following 5 months of operation, biomass proliferated on the surface of the material and a dark-red color was observed. With the obtained results, PE sponge is auspicious biomass carrier for growth of anammox bacteria.
