[Effect of Element Sulfur Particle Size and Type of the Reactor on Start-up of Sulfur-based Autotrophic Denitrification Reactor]

The effect of element sulfur particle size and type of the reactor on sulfur autotrophic denitrification reactor start-up was researched at room temperature(19-24℃) by using sulfur autotrophic denitrification bio-membrane reactor and anaerobic sludge bed biofilm reactor and inoculating anaerobic sludge. The research indicated that after 65 d operation, the bio-membrane reactor gained steady denitrification efficiency. With an influent NO₃^--N of 150 mg·L^-1, and an HRT of 3.3 h, the removal efficiencies of NO₃^--N and TN were 91% and 77%, and the removal rate of TN was 0.67-0.83 kg·(m³·d)^-1. The increase of volumetric loading rate of NO₃^--N and production of nitrogen gas led to the floating of sludge in the anaerobic sludge bed biofilm reactor. With an influent NO₃^--N of 185 mg·L^-1 and an HRT of 3.3 h, the maximum removal rate of NO₃^--N of 1.1 kg·(m³·d)^-1 was attained in anaerobic sludge bed biofilm reactor. But the increase of effluent NO₃^--N and NO₂^--N lowered the quality of effluent water seriously, and the floating of sludge affected the steady operation of the anaerobic sludge bed biofilm reactor. Sulfur particles with particle size of 0.8 mm and 3.0 mm were used as electron donors for start-up of two batch reactors. The experiment results indicated that the reactor which used sulfur particle size of 0.8 mm attained higher removal efficiency of NO₃^--N and TN, and its effluent accumulated less NO₂^--N compared with the reactor which used particle size of 3.0 mm.