Model-based evaluation of a new upgrading concept for N-removal

Area of Science:

• Environmental Engineering
• Wastewater Treatment Technologies
• Biotechnology

Background:

• Mathematical modeling is crucial for evaluating new wastewater treatment concepts, bridging lab-scale findings to full-scale applications.
• Bio-augmentation can achieve nitrification in activated sludge systems even with limited aerobic sludge retention time.
• Augmenting the endogenous nitrifying population is a key strategy for improving wastewater treatment efficiency.

Purpose of the Study:

• To evaluate the potential of bio-augmentation for enhancing nitrification in wastewater treatment plants.
• To assess a novel concept of implementing a nitrification reactor in the sludge return line.
• To compare the efficacy of bio-augmentation against conventional plant expansion using mathematical modeling.

Main Methods:

• Development of a mathematical model based on the TUDP model, implemented in AQUASIM.
• Application of the model to an existing wastewater treatment plant (WWTP Walcheren, The Netherlands) requiring upgrades.
• Comparative analysis of bio-augmentation versus extending existing aeration and anoxic tanks.

Main Results:

• Bio-augmentation in the return sludge line required only a 75% increase in total tank volume, including side stream tanks.
• Conventional extension of aeration basins and anoxic tanks necessitated a 225% volume increase.
• Modeling results provided a quantitative basis for evaluating the benefits of the bio-augmentation system.

Conclusions:

• Bio-augmentation in the return sludge line is a highly effective and space-saving strategy for upgrading wastewater treatment plants.
• Mathematical modeling enabled a confident decision for full-scale implementation, significantly reducing the scale-up period.
• This approach offers substantial cost and time savings compared to traditional expansion methods.