Research On Nitrogen And Phosphorous Removal For Low Temperature Waste Water

Biological nutrient removal (BNR) technology is always being the research development and application focus in the domestic and foreign wastewater treatment domain,and more and more new technics were devised in these years.Now the research of BNR is concentrated on the moderate temperature (25～35℃).But micro-organism was sensitivity to temperature,which the growth was restrained .That made the N and P of outwater not achieved the standard at low temperature (≤10℃). Therefore how to solve the problem that the N and P of outwater were not reached the standard in winter of north is the emphases of this research.The micro-organism was separate into the low temperature ,the moderate temperature and the high temperature micro-organism base on the different of temperature.The cold-adapted nitrobacteria were separated from the actived-sludge which was domesticated at low temperature,and carried through physiological appraisal. By using the method of embedding and soft PU foam,the immobilized cold-adapted nitrobacteria carrier were prepared,and the remove rate of NH3 can reach 70%.Compound technics to remove the N and P was designed to attain the application purpse of project base on the research of different technics to remove the N and P.This technics added contact-oxidation cell compared to invered A2/O which the carrier were plough into,and adopted biofilm technique in anaerobic cell. This technics achieved the separation of nitrobacteria, denitrifying bacteria and phosphate accumulating organisms(PAO) by controlling the sludge age strictly.It solve the contravention of the sludge age of these three microorganism in formerly reactor. The treating effect of this system was study at low and moderate temperature.The remove rate of NH3,COD and T-P can reach 90%,90% and 80% eachly at moderate temperature;and the remove rate of NH3,COD and T-P can reach 85%,85% and 70% eachly at low temperature.The remove rate of T-N was only 35% at low temperature because of the infection temperature.The best condition of running was ascertained by researching the effect of C:N,pH and tmperture change at low and moderate temperature. It have immensity meaning to the remove of N and P in the cold temperature field because this technics breached the limit of temperature and wided the scope of N and P remove. It also provided one way to research the N and P removing by microbiology at low temperature.