Biological nitrogen removal with the Anaerobic-ammonium-oxidation(Anammox) process

An up flow anaerobic sludge blanket(UASB) reactor was operated in order to investigate the effects of hydraulic retention time(HRT) on nitrogen removal performance over the Anammox process as shortening HRT to improve the system load.Results showed that(1) the reactor seeded with granular sludge biomass enriched Anammox was started up rapidly(within 14 days),(2) the nitrogen removal performance appeared good steadily during the HRT tests(in 91 days) and the nitrogen removal efficiency fluctuated in growth with the shortening of HRT.The average NH4+-N,NO2--N and total nitrogen removed efficiency were over 70.0%.(3) The biggest total nitrogen loading rate and total nitrogen removal rate were 2.04 kg N·m-3·d-1 and 1.56 kg N· m-3·d-1 respectively.(4) The reactor could strictly follow the principles of anammox denitrification process,as the ratio of NH4+-N(removal biomass),NO2--N(removal biomass) and NO3--N(product biomass) was 1:1.15:0.22 during the whole experiment,which was very closed to the theory values of anammox process(1:1.32:0.26).