Research On The Combine Nitritation-ANAMMOX Process And Its Treatment On Ammonium-rich Wastewater

Accumulation of ammonia in water environment has induced serious deterioration to the quality of water environment. Nitrogen from the wastewaters with low C/N ratio and high strength ammonia, such as digested sludge supernatant and landfill leachate , add up to over 50% total nitrogen form wastewater. Due to the fact that these wastewaters often are riddled by an extremely unfavourable C/N ratio, for the conventional biological nitrification-denitrification, C/N ratios below 4 increase the denitrification volume by a factor of 1.5 to 1.7, with a ratio below 2.5, sufficient denitrification cannot be achieved at all without the use of external carbon sources. Due to the fact that these wastewaters often are riddled by an extremely unfavourable C/N ratio, it is unfit to removal nitrogen from these wastewaters by biological nitrification-denitrification.Based on the latest research findings on biological nitrogen removal on low C/N ratio and high strength ammonia wastewater in both domestic and abroad, start-up and optimization of partial nitrification matched with ANAMMOX(Anaerobic Ammonium Oxidation) was studied in CSTR (Continuous Stired Tank Reactor) with different dissolve oxygen level by using normal activated sludge as inoculating sludge, the ANAMMOX reactor was started up from the deammonification biofilm, finally the combine nitritation -ANAMMOX process for treatment low C/N wastewater with high strength ammonia was achieved.The experiment results show that 50% of the ammonium in the liquor was converted to nitrite with the temperature about 28 +1℃ at the DO (dissolve oxygen) concentration of 0.5-1.0 mg/L in the nitritation reactor, the nitritation was also obtained with the condition of the DO about 0.3-0.5 mg/L, but its ability of resistance to load impact was comparatively feeble, the bicarbonate (NaHCO3) was the buffer dosage and limiting substrate for the autotrophic bacteria without addition of organic carbon source (COD). The optimum temperature in the range of 28 and 32℃ and pH about 7.0-7.9 adapted to the nitritation, furthermore ,DO concentration at 0.5-1.0 mg/L and a HRT (hydraulic retention time) of 1 day were favourable conditions of nitritation matched with ANAMMOX.Start-up of the ANAMMOX reactor was achieved relatively fast by using the the deammonification biofilm. When the organic carbon source was added in the influent, heterotrophic bacterium increased rapidly, as a result, ANAMMOX was inhibited by...