The Removal of Ammonia Nitrogen in Sewage by Hollow Fiber Bioreactor

The hydrophilized polysulphone hollow fiber(pore size 0.2µm)was used as supports for immobilization of the bacteria.The nitrification and denitrification bacteria isolated from sewage treatment plant were immobilized as thin film on the surface of the hollow fibers.The hollow fiber bioreactor was possible to supply the oxygen to the surface bacteria from the imer side of the fiber by diffusion，The capacity coefficient value(KLa)when the oxygen was transferred to the water attained1 70h^&lt；-1&gt；。Continuous nitrification was carried out at a loading rate of 18a mg-N/h.The nitrificatian rate increased in proportion to the concentration of ammonia nitrogen，The dependenee of ammonia nitrogen concentration on the nitrification rate correlated as follow.γ=103C^&lt；0.142&gt；The rate was also affected by oxygen amounts supplied from inner side of the hollow fiber.The high efficiency was attained at pressure of over 0.2 MPa。On the other hand，the rate decreased by the soluble BOD.It wa…More s considered that BOD oxidation bacteria had advantage over the nitrification bacteria at high level of BOD.In conclusion，high efficiency of the hollow fiber bioreactor was brought about by the synergistic effects of the high value of KLa，the large.Driving force.(C^&lt；*&gt；-O in oxygen diffusion at high air pressure and the high value of the effectiveness factor(η)of immobilized biocatalist。The denitrification bacteria were also immobilized on the surface of the hollow fiber through the medium of PVA。The rate increased in proportion to the TOC ratio，and was attained to maximum(1 30 mg-N·h)at 1.0 of TOC ratio in case of ethanol，methanol and ethanolamine。This was assumed by stoichiometry in the denitrification reaction。The dependence of nitrate concentration(C)on the denitrification rate(R)was investigated。Best fit was found for the@equation as follow，r=1.15C^&lt；0，77&gt；The denitrification ability of hollow fiber reactor was effective in wide range of nitrate concentration(500 mg-N/l)of waste water.The hollow fiber reactor in this research indicated the highest denitrification rate of 287 mg-N/l·h.This novel hollow fiber reactor was considered very effective for removal of nitrate in the waste water.The field test using the true sewage carried out at the sewage plant。In the empirical plant installed the continuous denitrification/nitrification reactor，140 mg-N/l·h of nitrification rate and 120 mg-N/l·h of denitrification rate were obtained and the denitrification efficiency of 80%and the nitrification efflciency of 100%attained。Less：Less

The hydrophilized polysulphone hollow fiber (pore size 0.2 μm) was used as supports for immobilization of the bacteria. The nitrification and denitrification bacteria isolated from sewage treatment plant were immobilized as thin film on the surface of the hollow fibers. The hollow fiber bioreactor was possible to supply the oxygen to the surface bacteria from the imer side of the fiber by diffusion, The capacity coefficient value (KLa) when the oxygen was transferred to the water attained 1 70 h^<-1>. Continuous nitrification was carried out at a loading rate of 18a mg-N/h. The nitrificatian rate increased in proportion to the concentration of ammonia nitrogen, The dependenee of ammonia nitrogen concentration on the nitrification rate correlated as follow.γ = 103 C^<0.142> The rate was also affected by oxygen amounts supplied from inner side of the hollow fiber. The high efficiency was attained at pressure of over 0.2 MPa. On the other hand, the rate decreased by the soluble BOD. It wa … More s considered that BOD oxidation bacteria had advantage over the nitrification bacteria at high level of BOD. In conclusion, high efficiency of the hollow fiber bioreactor was brought about by the synergistic effects of the high value of KLa, the large. driving force. (C^<*>-O in oxygen diffusion at high air pressure and the high value of the effectiveness factor (η) of immobilized biocatalist. The denitrification bacteria were also immobilized on the surface of the hollow fiber through the medium of PVA. The rate increased in proportion to the TOC ratio, and was attained to maximum (1 30mg-N・h) at 1.0 of TOC ratio in case of ethanol, methanol and ethanolamine. This was assumed by stoichiometry in the denitrification reaction. The dependence of nitrate concentration (C) on the denitrification rate (r) was investigated. Best fit was found for the equation as follow, r = 1.15 C^<0, 77> The denitrification ability of hollow fiber reactor was effective in wide range of nitrate concentration (500mg-N/l) of waste water. The hollow fiber reactor in this research indicated the highest denitrification rate of 287 mg-N/l・h. This novel hollow fiber reactor was considered very effective for removal of nitrate in the waste water.The field test using the true sewage carried out at the sewage plant. In the empirical plant installed the continuous denitrification/nitrification reactor, 140mg-N/l・h of nitrification rate and 120mg-N/l・h of denitrification rate were obtained and the denitrification efficiency of 80% and the nitrification efflciency of 100% attained. Less