Research Of Shortcut Nitrification-denitrification And Denitrifying Phosphorus Removal In SBR Under The Real-time Control

The eutrophication of water environment has drawn increasing attention because of the excess emissions of nitrogen and phosphorus,as one of the most environmental problems human concerns.To improve nitrogen and phosphorus removal efficiency in the traditional nitrogen and phosphorus removal process,and to develop efficient,energy-saving wastewater treatment technology,become hot spots in sewage nitrogen and phosphorus removal technology.The subject investigates the self-simulated sewage,to realize the whole on-line control of shortcut nitrification-denitrification process in SBR system.The results show that in the shortcut nitrification-denitrification process,DO,ORP and pH change with the COD and the concentration of NO_X~-.There is a good correlation among different changes.The nitrification and denitrification process can be controlled basing on DO,ORP,pH changes in real-time control.In the stage of nitrification,the second time DO value increases and maintains stability, a platform of ORP,pH value turns to the low point and then rises up,can be used as the responses to the end of the shortcut nitrification stage.Also in the denitrification stage,pH value turns to the peak value and then decline,combining with the value of ORP declining rate slowed,these changes can point to the end of the denitrification.Running through real-time control of shortcut nitrification-denitrification process,nitrification shortened to 210 minutes, denitrification shortened to 45 minutes.Compared with the traditional fixed-time mode of the process,it has saved reaction time and energy.At the same time the subject study the real-time control process of denitrifying phosphorus removal on the different electron acceptors,using pH and ORP as control parameters.The results obtained,whether nitrite or nitrate as the electron acceptor in nitrifying phosphorus removal system,there is a close correlation among the changes of pH and ORP,the concentration of COD and phosphate.ORP can be used as a control parameters in denitrifying phosphorus removal process.We can control the phases of anaerobic denitrifying phosphorus and anoxic reaction by means of real-time control.Moreover pH is an important parameter in denitrifying phosphorus removal process,the changes of its value combined with ORP change may may control anaerobic reaction time.But we can not determine whether it can be used as the instruction parameter to indicate the end of the anoxic reaction.Through the real-time control of denitrifying phosphorus removal using nitrite and nitrate as the electron acceptors,the anaerobic reaction time of the two systems is controlled to 180 min,and the anoxic reaction time is controlled respectively for 175 min and 155 min.As well it has greatly shortened the anaerobic and anoxic running time and saved energy consumption.Finally the subject investigate the shortcut netrification-denitrification and denitrifying phosphorus removal process by changing the concentration of the ingredients,such as N,P, in simulated water.We inspect the nitrogen and phosphorus removal efficiency under the conditions of different N,P system.The results showed that the complex system have good effects in disposing the high concentration and low concentration of nitrogen and phosphorus wastewater.The rates of the COD and ammonia nitrogen,phosphate removal respectively are 89-80%,95-96%and 88.9-91.5%.The experiment also showed that when the concentration of N/P falls to a certain degree,the amount of the electron acceptor in the anoxic reaction stage is inadequate,it will make the efficiency of phosphorus removal decrease.