UNITANK N,Premoval Function Research

With the rapid development of industrialization and urbanization and the improvement of wastewater discharge standards, the wastewater treatment plants (WWTPs) in our country is tend to adopt new technologies for both nitrogen and phosphorus removing. It is of great importance to develop new processes systems which are cost-efficient, reliable, less land contained and removing N, P simultaneously.UNITANK is a new wastewater treatment technology, which is a development and changing from SBR(Sequencing Batch Reactor).it is combined with the advantages of SBR, normal aeration tank and 3-ditch oxidation treatment systems. As intermittent influent in SBR, large land area in 3-ditch oxidation treatment system and too many facilities in normal aeration tank system, it also avoids disadvantages of these systems. UNITANK could remove N and P at the same time.A typical UNITANK system has 3 tanks, which hydraulic connects with each other. Each tank installs an aeration system, the outside two tanks includes effluent weirs and sludge slot. They are used as the aeration tank and the settling tank alternately.Wastewater enters any tank of these three ones. It is continuous influent and alternate work. Under automatic control, UNITANK could undergo aerobic, anoxic and anaerobic processes and remove organic materials and N, P. UNITANK proved to be a high efficiency, economic, flexible and fully-fledged wastewater treatment technology in the world. Based on the UNITANK research in our country, this article mentioned three new UNITANK methods, which are different from the typical one and studied the processes of those 3 new methods. This article analyzed the kinetics of N and P removal. It introduced the UNITANK processes in detail, and researched the N, P removal effect under different conditions of those 3 new methods. It indicated that the removal of P is the key to N, P removal effect. UNITANK arranged treatment processes specially or added a special anaerobic tank to solve the problem and create good living condition for nitrifying bacteria and phosphorous bacteria. It made favorable condition for removing N and P.While aided with B/E(biological /chemistry)method, adding chemical coagulants in treatment, it could enhance the P removal effect. The experiments indicated that under the most economic condition, using PAF could make TP removal of 70.5% and 0.17mg/L in effluent(<0.5mg/L),COD removal of 68.2%,ammonia nitrogen removal of 39.7%.Our experiments proved UNITANK had a certain effect of N and P removal, but need further study in P removal.This article could propose some advice for UNITANK application.