Research On Improving Sewage Dephosphorization Efficiency Of Water Treatment Plant

Eutrophication is one of the most serious water pollution at home and abroad. In recent years, the sewage treatment ratio is rising ceaselessly with the development of the biological treatment system, but the eutrophication problem caused by the nitrogen and phosphorus still could not be solved effectively. Therefore, how to improve the phosphorus removal efficiency in the traditional biological dephosphorization process becomes an important topic to be solved at the present stage.PAOs is the main part of activated sludge technique in phosphorus removal. As a biological selector of PAOs, anaerobic zone plays an important role in biological phosphorus removal. To improve the efficiency of biological phosphorus removal, it is necessary to improve the content and activity of PAOs and reduce the factors that affect the anaerobic state. So the subject has done a research on how to improve biological phosphorus removal efficiency with the method of bench simulation experiment and confirm the feasibility of the designed equipment at the same time.The equipment has set hydrolysis pool to hydrolyze and Pre acidize the waste water, after being hydrolyzed and acidized, the content of micromolecule and biodegradable organisms—VFA increase obviously which have provided enough substrate for the PAOs to absorb these substances to combine PHB in anaerobic state and then improve the release effect of phosphorus in the anaerobic state and provide enough PHA for the follow-up phosphorus uptake in the aerobic condition. In addition, the organics biochemical qualities have improved after being hydrolyzed and acidized, then it will be much more easier to remove these organics in the follow-up process. The equipment has also set the high-load aerobic biological pool. According to the contrast test of the release of phosphorus in the anaerobic state and the absorb of phosphorus in the aerobic state and the test of the change of the activated sludge population increment, we find that the high-load aerobic biological pool can not only improve the content of PAOs, but also increase its activity. It can improve the phosphorus removal effect from 75% to more than 90%.The equipment has set a mud bank, according to the experiment study, the tank can reduce the factors that affect the release of phosphorus in the anaerobic state and reduce the dissolved oxygen and nitrate nitrogen, then the anaerobic tank as a biological selector can supply a beneficial anaerobic environment for the release of phosphorus and a beneficial condition to improve the phosphorus removal effect.