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Abstract: The performance of high-loaded anaerobic ammonium oxidizing (ANAMMOX) upflow anaerobic sludge bed (UASB) reactors was investigated. Two ANAMMOX reactors (R1 with and R2 without effluent recycling, respectively) were fed with relatively low nitrite concentration of 240 mg-N L−1 with subsequent progressive increase in the nitrogen loading rate (NLR) by shortening the hydraulic retention time (HRT) till the end of the experiment. A super high-rate performance with nitrogen removal rate (NRR) of 74.3–76.7 kg-N m−3 day−1 was accomplished in the lab-scale ANAMMOX UASB reactors, which was 3 times of the highest reported value. The biomass concentrations in the reactors were as high as 42.0–57.7 g-VSS L−1 with the specific ANAMMOX activity (SAA) approaching to 5.6 kg-N kg-VSS−1 day−1. The high SAA and high biomass concentration were regarded as the key factors for the super high-rate performance. ANAMMOX granules were observed in the reactors with settling velocities of 73–88 m h−1. The ANAMMOX granules were found to contain a plenty of extracellular polymers (ECPs) such as 71.8–112.1 mg g-VSS−1 of polysaccharides (PS) and 164.4–298.2 mg g-VSS−1 of proteins (PN). High content of hemachrome (6.8–10.3 μmol g-VSS−1) was detected in the ANAMMOX granules, which is supposed to be attributed to their unique carmine color. [ABSTRACT FROM AUTHOR]

Abstract: The effect of organic matter on the nitrogen removal performance of anaerobic ammonium oxidation (Anammox) process was investigated in an upflow anaerobic sludge blanket (UASB) reactor fed with nitrogen loading rate of 13.92kgNm−3 day−1 at an HRT of 0.83h. Mass balance showed that the heterotrophic denitrification prevailed in the UASB reactor, and became the dominant reactions when high influent COD/–N ratios of 2.92 were applied. The Anammox bacterial growth was significantly suppressed by denitrifying communities under high organic matter content due to the weaker competition for nitrite (electron acceptor) and living space. Long-term operation of the Anammox UASB reactor under relatively high organic content resulted in weak recovery performance. [Copyright &y& Elsevier]

Abstract: Vigorous anaerobic ammonium oxidation (anammox) activity was realized by seeding with diverse sludge contents. Granules taken from a 2-year old methanogenic reactor loaded with high organic and methanol contents were used as inoculum to enrich anammox biomass in a 1.1L upflow anaerobic sludge blanket reactor. Anammox activity appeared after an operation of 83d resulting in the final nitrogen removal rate of 11.7kgNm−3 d−1 with the efficient granulation of anammox sludge. The analysis based on 16S rDNA sequencing confirmed that Candidatus “Brocadia” was the dominant population in the enriched biomass. [Copyright &y& Elsevier]