Comparison of the calculation results for aeration tanks using the NII VODGEO/SamGTU and ASM2d models

Summary

Проведено сравнение результатов расчета аэротенков, реализующих процессы аэробного окисления органических соединений, нитрификации, денитрификации и удаления фосфора (химического и биологического) по двум различным математическим моделям (методикам): ВОДГЕО/СамГТУ (Самарского государственного технического уни-
The paper presents a comparison of the results of calculating aeration tanks where the processes of aerobic oxidation of organic compounds, nitrification, denitrification and phosphorus removal (chemical and biological) according to two different mathematical models (methods): VODGEO/SamGTU (Samara State Technical University) and ASM2d have been implemented. These models are theoretical and describe the processes of biological wastewater treatment using enzymatic kinetics formulas. Calculations for the same input and output data showed a high reproducibility in terms of the volumes of the process zones of aeration tanks. For the quality of effluent meeting the MPCs for fishery water bodies (option 1), the discrepancy is –0.3 and 3.3%, respectively, for the anoxid and aerobic zones. With indicators for effluent discharge into a water body of category B (option 2) for large-scale to extremely large-scale facilities, the difference in the results of calculating the volumes was 13.8 and 15.4%, respectively. While making calculations with account of the effluent quality reaching the process indicators for discharge into a water body of category G (option 3) for large-scale to extremely large-scale facilities, the discrepancy in the values of the volumes of aerobic zones was 48% owing to the expediency of ensuring stable nitrification at high loads. Therefore, option 3 according to the VODGEO/SamGTU method was actually performed for a lower sludge load and more enhanced nitrification than according to the ASM2d method (1 instead of 2 mgN–NH₄/l). It is shown that the mathematical models underlying both methods, based on the fundamental equations of the enzymatic reaction, a very high reproducibility and consistency of the calculation results give grounds to assert that both of these models are, to the greatest extent known, acceptable for calculating biological treatment facilities with the removal of nitrogen and phosphorus.

Key words

biological treatment , nitrification , denitrification , activated sludge , kinetic constants , industrial and municipal wastewater , VODGEO/SamGTU and ASM2d process calculation methods , theoretical and empirical mathematical models , comparative calculation of the biological treatment facilities