Kinetic coefficients of cell growth and removal of organic substances for modeling Anaerobic-anoxic-aerobic method

Abstract

Abstract

Purpose

Anaerobic-anoxic-aerobic process is one of the biological removal processes of nutrients in wastewater treatment. Phosphorus removal by biological method is a new and developed technique that is done by changing the design of suspended growth systems.

Methods

This is a cross-sectional descriptive study, which is a pilot workshop based in the first module, and chemistry, physics and microbiological tests were carried out at the wastewater treatment plant laboratory in one of the cities (Pardis) of Tehran province in 2020–2021 during a period of 12 months. Was completed. In this research, a total of 500 samples were taken from raw wastewater, aeration pond, effluent, secondary sedimentation and return activated sludge.

Results

In this research, the internal decay coefficient and the growth efficiency coefficient are equal to d⁻¹ 0.1264 and 0.6579 gVSS/gCOD, respectively. And the maximum specific rate of consumption of food substance and the semi-saturation constant of food substance respectively were gCOD/gVSS.d 3.3467 gCOD/m 25.305. If the specific rate of consumption of food substance or efficiency factor in our research is 0.27 gCOD/gVSS.d and the semi-constant Ks saturation equal to 27.9 gCOD/m has been obtained, this actually shows that the organic matter (COD) in the waste water of Pardis city had a higher degradability (sbCOD).

Conclusion

According to the obtained results, the synthetic coefficients in the Lineweaver–Burk and Hanes models are suitable, but in the Hofstee model, the amount of K and K_d is less than the optimal amount for the proper exploitation of the pilot.