Research On Outside Cycle Reactor Treating Low Concentration Sewage Water Under Regular Temperature

Water environment in China was badly polluted with the development of economy. The treatment of sewage in the small town is one of the most urgent problems. The traditional aerobic biologic technology is not widely used to treat the small town sewage because of its high energy consumption and high capital expenditure. As the energy crisis break out in the late years, the sewage treating technology with low energy consumption and low cost are searched. Anaerobic biologic method is one of the best technologies. The anaerobic reactor has been used to treat the urban sewage since 1980s.The treatment effect was comparatively researched between the outside cycle reactor and the Expanded Granular Sludge Bed (EGSB) to treat the make-up municipal wastewater under the normal temperature in this paper. Conclusions are as follows.Both the reactors are started up when the COD of influent is 300mg/L and the room temperature is separately 13℃ and 30℃. The result showed that both reactors are more easily to start up under the higher temperature. After seven days running, the steady and high organic matter removal efficiency can be reached in both the reactors, besides the better treatment effect is put up in the outer cycle reactor.In the following shock test the average organic matter removal efficiency in the EGSB is 80.6%, the average organic matter removal efficiency in the outer cycle reactor is 82.6%, when the COD of influent is changing from 500mg/L to 1000mg/L. It also can be found that the better treatment effect is put up in the outer recirculation reactor although the removal efficiency is not so steady. When the COD of influent is constantly changing, the outer cycle reactor can endure the change better and remove the organic matter more steadily. The study on the granular sludge which is taken out from the bottom of reactor showed that the particle diameter of granular sludge is well-proportioned. It can be concluede that the granular sludge can not be washed out to be broken when the reactor endure the high organic load shock because of its certain intensity.Research on stable operation of two reactors showed that: processing effect of two reactors became better and better when the velocity of upflow increased from 1.70m/h to 9.00m/h, although the increasing speed is lower. When the reactor is under...