Does Continuous Bioaugmentation of Aerated Stabilization Basins Improve Performance? A Field Scale Trial With a...

Area of Science:

• Environmental Science
• Environmental Microbiology
• Industrial Biotechnology

Background:

• Continuous bioaugmentation is common in the pulp and paper industry to enhance wastewater treatment.
• However, research indicates that bioaugmentation success is often unpredictable.
• Wastewater treatment systems may be undersized in volume, aeration, or nutrient supply.

Purpose of the Study:

• To evaluate the effectiveness of a commercial bioaugmentation product in a pulp and paper mill's aerated lagoon system.
• To assess the impact of bioaugmentation on wastewater treatment performance metrics.
• To investigate the microbial community changes associated with bioaugmentation.

Main Methods:

• A 6-month field-scale trial was conducted on two identical aerated stabilization basin (ASB) trains.
• One train was bioaugmented with a commercial product, while the other served as a control.
• Trains were switched mid-trial to mitigate train-specific effects, and 16S rRNA gene sequencing was used.

Main Results:

• No significant changes in soluble or total biochemical oxygen demand (sBOD5, TBOD5) or total suspended solids (TSS) were observed in the first set of ponds.
• The second set of ponds showed higher TBOD5 (6.0 ± 2.6 mg/L) and TSS (12.4 ± 5.2 mg/L) in the bioaugmented train.
• 16S rRNA gene sequencing revealed high levels of Thiothrix in the bioaugmented train, correlating with increased TSS.

Conclusions:

• The observed increases in BOD and TSS were attributed to a filamentous bacterial bloom (Thiothrix), not the bioaugmentation product itself.
• Bioaugmentation did not demonstrably improve the performance of the aerated lagoon system.
• The study highlights the unpredictable nature of bioaugmentation and the importance of microbial community analysis.