| There are lots of biological wastewater treatment equipments in service areas of express highway in our country. The biological processes include biological contact oxidation, activated sludge, Membrane Bioreactor (MBR) and Sequencing Batch Reactor (SBR). Scientifically and rationally simulating and controlling of these wastewater treatment processes will not only assure effluents achieve the standards stably, but also lower the operation cost.Modeling of activated sludge process has become a common part of design and operation of wastewater treatment plants all over the world. There are several researches overseas, and some models have been pushed out. Introduction of ASMs has spurred and focused research internationally.From Monod mode, Eckenflder mode, McKinney mode, Lawrence-McCarty mode to Andrews mode, WRc mode and ASMs are reviewed, applications of activated sludge models at home and abroad are presented. Computer simulators SSSP, EFOR, GPS-X and WEST are also introduced.In three situations within Continuous Stirred-Tank Reactor (CSTR) as'heterotrophic bacteria's growth and decay under aerobic conditions','hydrolysis & heterotrophic bacteria's growth and decay under aerobic conditions','hydrolysis & heterotrophic bacteria and autotrophic bacteria's growth and decay under aerobic conditions', stable-state models based on ASM1 and ASM3 are set up. Analytical solutions are achieved in situation of'hydrolysis & heterotrophic bacteria's growth and decay under aerobic conditions', simulations are made with default inlet data and parameters to the two former situations by MATLAB program.As to the artificial wastewater similar with domestic sewage, an experiment of submerged membrane bioreactor has been taken during the last 4 months under different HRTs and temperatures. According to IWA's new division principle of organic components, the organic components of artificial wastewater are measured. Transient-state models based on ASM1 and ASM3 are established, simulations are taken by MATLAB program, and a best group of parameters under the experiment condition is found with least square method. Because of the special periodic operation mode of DE oxidation ditch, an operation period is divided into 4 stages, and transient-state models based on ASM1 and ASM3 are established to the system'Anaerobic Selection Tank + DE Oxidation Ditch + Final Sedimentation Tank'. Simulations are made with default parameters by MATLAB program.The conclusions are achieved as follows:(1) Simulations of stable-state models of CSTR based on ASM1 and ASM3 in'hydrolysis & heterotrophic bacteria's growth and decay under aerobic conditions'show that effluent SS falls sharply when SRT increases, and then becomes stable. XB,M increases with SRT, then becomes stable. XS falls sharply when SRT increases, and then becomes stable. XI and MLSS increase with SRT. Activity proportion increases sharply when SRT increases, and then decreases continuously. Oxygen demand increases with SRT and then becomes stable.(2) Sensitivity analysis of MBR model based on ASM1 shows that simulation of COD is sensitive to bH, KS, (μ|^)H, NH4-N is sensitive to (μ|^)A, bA, KNH, NOx-N is sensitive to YH, iXB, fP, bH, YA, (μ|^)A, bA, (μ|^)H, KNH, KS.(3) Sensitivity analysis of MBR model based on ASM3 shows that simulation of COD is sensitive to YSTO,O2,YH,O2,fSI,bH,O2,KS,kSTO,NH4-N is sensitive to (μ|^)A, bA,O2, KA,NH4, NOx-N is sensitive to YA, YSTO,O2, YH,O2, bH,O2.(4) Simulations to stable-states models of MBR show that under the experiment condition, ASM1 and ASM3 have the same effect in COD simulation, but ASM3 is better than ASM1 in NH4-N and NOx-N simulations, and ASM3 has a better simulation effect than ASM1 conclusively.(5) Sensitivity analysis of DE Oxidation Ditch model based on ASM1 shows that simulation of COD is sensitive to bH,bA,KS,(μ|^)H,YH,kh,fP,KNO,YA,ηg,iXB,KNH,(μ|^)A,ηh,KX,NH4-N is sensitive toηh, KS, bA, fP, KNO, (μ|^)A, YA,ηg, kh, KNH, (μ|^)A, iXB, YH, KX, bH, NOx-N is sensitive toηh,KS,bA,YH,fP,KNO,(μ|^)H,YA,ηg,kh,iXB,KNH,(μ|^)A,KX,bH.(6) Sensitivity analysis of DE Oxidation Ditch model based on ASM3 shows that simulation of COD is sensitive to fSI, kSTO, KS, bH,O2, YSTO,O2, YH,O2, NH4-N is sensitive to (μ|^)H, KA,NH4, bA,O2, YSTO,O2, YH,O2, bH,O2, bA,NOx,ηNOx, kh, KX, NOx-N is sensitive to YA,YSTO,O2,YH,O2,bH,O2,ηNOx,kSTO,YSTO,NOx,bSTO,O2,(μ|^)H,(μ|^)H,KSTO,KA,NH4,YH,NOx,KS,bH,NOx,bSTO,NOx.(7) Simulations with default parameters to transient-state models of DE Oxidation Ditch show that COD, NH4-N and NOx-N of ASM3 are changing in conformity with practical situation. Conclusively, ASM3 has a better simulation effect than ASM1 as far as DE Oxidation Ditch is concerned.
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