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Published on: December 25, 2015
Bioaugmentation to improve nitrification in activated sludge treatment
Shao-Yuan Leu1, Michael K Stenstrom
1Civil and Environmental Engineering Department, University of California, Los Angeles, CA 90095, USA. syleu@ucla.edu
Summary
Bioaugmentation enhances nutrient removal in wastewater treatment, potentially reducing infrastructure needs. Different onsite bioaugmentation methods offer varying benefits for nitrification and sludge retention time, especially at lower temperatures.
Area of Science:
- Environmental Engineering
- Microbial Ecology
- Wastewater Treatment
Background:
- Bioaugmentation is a promising strategy to enhance nutrient removal in municipal wastewater treatment.
- Current bioaugmentation methods vary, with limited comparative studies on their effectiveness.
- This research addresses the need to quantify and compare different onsite bioaugmentation approaches.
Purpose of the Study:
- To quantify the effectiveness of different bioaugmentation processes for nutrient removal.
- To investigate and compare three major onsite bioaugmentation alternatives: parallel-plants, enricher-reactor, and enricher-reactor/return activated sludge (ER-RAS).
- To simulate and present the benefits of these approaches using kinetic models.
Main Methods:
- Development of kinetic models to simulate three distinct onsite bioaugmentation approaches.
- Comparison of approaches based on controllable parameters like bioaugmentation levels, aeration tank volume, and temperatures.
- Simulation of upgrading a carbon-only wastewater treatment plant to nitrification.
Main Results:
- All simulated bioaugmentation approaches successfully decreased the minimum sludge retention time (SRT) required for nitrification.
- The parallel-plants approach yielded the highest biomass concentration but showed temperature sensitivity.
- The ER-RAS approach demonstrated utility at lower temperatures and required less reactor volume, while the enricher-reactor approach was advantageous with inhibitory compounds.
Conclusions:
- Bioaugmentation offers a viable strategy to improve nutrient removal and reduce infrastructure in wastewater treatment plants.
- The choice of bioaugmentation approach (parallel-plants, enricher-reactor, ER-RAS) depends on specific operational conditions, including temperature and the presence of inhibitors.
- Kinetic modeling provides a valuable tool for evaluating and optimizing bioaugmentation strategies for enhanced wastewater treatment.
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