Computer Modeling Of Activated Sludge System

Based on Activated Sludge Model No. 1 (ASM1) and one-dimensional layered settler model including hydraulic factors, general modeling program of activated sludge system is developed by computer compiled language Visual C++ 6.0. Combined with previous studies, a computer modeling protocol is also presented for activated sludge system.On the basis of ASM 1 advanced by IAWQ task group, general modeling program SM-ASM1 is compiled by language VC++ 6.0 and used for stable modeling calculation of modeling case in IAWQ reports, with modeling results close to those of IAWQ task group. The compilation of general modeling program is completely based on matrix, which is brief, compact, universal, expansible and transplantable.Based on the idea of one-dimensional layered model of settler and Takacs settling velocity model, a one-dimensional layered settler model including hydraulic factors and biochemical reactions is developed and corresponding modeling program is compiled by VC++ 6.0 language. Algorithm and calculating program for sludge blanket height is presented;and a parameter calibration protocol based on conventional water quality index SS and SVI is brought forward for final settler. The model is validated by pilot-scale experimental data and practical operational data of waste water treatment plant (WWTP), the modeling results indicating that this model can effectively simulate suspended solid (SS) concentration profile in final settler, SS concentration in effluent and underflow, and sludge blanket height.Combined with previous studies, a computer modeling protocol with detailed discussion for each step of main structural process is also presented for activated sludge system. Meanwhile, a sensitivity analysis protocol is also advanced for activated sludge system with concrete case for its practical application. A WWTP case in COST 624/682 simulation benchmark is modeled by the general modeling program.Compared with modeling results provided by COST 624/682, results of the general modeling program have very small deviation. Especially for one-dimensional layered settler model including hydraulic factors, its modeling results can be corresponding to those of various simulation softwares by adjusting dispersion coefficient D.