Substrate storage concepts in modeling activated sludge systems for tannery wastewaters

Area of Science:

• Environmental Engineering
• Wastewater Treatment Modeling

Background:

• Activated sludge models are crucial for wastewater treatment but lack calibration for industrial effluents.
• Tannery wastewater presents complex substrates, challenging existing modeling approaches.

Purpose of the Study:

• To develop a conceptual framework for applying activated sludge models (ASM1, ASM3, and others) to industrial wastewater, specifically tannery effluents.
• To compare the performance of five different models under dynamic conditions with simultaneous growth and storage.

Main Methods:

• Application of multiple activated sludge models (ASM1, ASM3, etc.) to simulate tannery wastewater biodegradation.
• Comparative analysis of simulation results from five distinct models.
• Evaluation of model performance based on dynamic conditions, growth, and storage.

Main Results:

• More detailed model structures generally improve the accuracy of simulating real-world industrial wastewater scenarios.
• Experimental determination of storage products in complex substrates hindered accurate coefficient calibration for structured models.
• Modeling results highlighted challenges in defining readily biodegradable Chemical Oxygen Demand (COD) across different Food-to-Microorganism (F/M) ratios.

Conclusions:

• While structured models offer better dynamic behavior description for tannery effluents, experimental data limitations impede precise calibration.
• Accurate process stoichiometry and wastewater fractionation require further investigation with additional data for reliable model calibration using respirometric batch tests.