Part 12: **Optimizing Wastewater Treatment with Advanced Ammonia Control Strategies: A Simulation-Based Approach** 🌊The content explores the ...
Published on by Hossein Ataei Far, Deputy Manager of the Research, Technology Development, and Industry Relations Center at NWWEC
The content explores the optimization of wastewater treatment plant (WWTP) operations through advanced ammonia control strategies designed to manage peak loading issues. Key aspects include:
- **🔍 Ammonia Sensor Placement**: Installing an ammonia sensor at the end of the aerobic zone (feedback control) can lead to delays in responding to peak loads, risking effluent limit violations, especially with sensors that have slow response times (over 30 minutes).
- **📈 Feed-Forward Control Solution: An additional ammonia sensor is positioned upstream of the aeration zone as part of a feed-forward control approach suggested to speed up response times. Peak loads may be detected early with this setup, allowing aeration to be modified appropriately.
- **⚙️ Control Strategies**: Various control concepts have been evaluated:
- On-off control of blowers based on ammonia concentration.
- DO set-point adjustments based on ammonia concentration.
- Combination of feedback and feed-forward control using a maximum condition approach.
- **🧪 Simulation Studies**: Detailed simulations at WWTPs Morgental, Thunersee, and Werdhoelzli were conducted to test and refine these control concepts. The simulations helped design, test, and select the best control systems tailored to each plant's characteristics.
- **💰 Cost and Performance Evaluation**:
- Advanced control strategies led to significant cost savings. The best control version (excluding separate supernatant treatment) reduced energy costs by 25% and chemical usage by over 50%. Total cost reductions could be around 30% when considering effluent load taxes.
- Implementing separate treatment for digester supernatant (Anammox) further increased net savings and improved nitrogen removal efficiency to over 80%.
- **⚠️ Challenges and Limitations**:
- Simulation uncertainties mainly arise from input data variations and model limitations, particularly in denitrification and biological phosphorus removal accuracy under low oxygen conditions.
- Potential negative effects of low oxygen, such as increased nitrite concentrations and filamentous organisms growth, were also considered.
- **🔧 Implementation**: WWTP Werdhoelzli began implementing the upgraded process scheme with ammonia-based control, though the upgrade is not yet complete.
Overall, the study highlights the potential for advanced control strategies to enhance operational efficiency, reduce costs, and improve effluent quality in wastewater treatment.
hashtag
hashtag#AmmoniaControl
hashtag#FeedForwardControl
hashtag#SimulationStudies
hashtag#ProcessOptimization
Reference:
[1] Rieger. Leiv, and et al. (2012).
Fig 1. Wastewater Treatment Plant Model- Ref: Abdul Gaffar Sheik and et. al., 2021