Metagenomics Proved Low DO Community Can Save Big Money

What was the value proposition?

The estimated capital costs of a Biological Nutrient Removal (BNR) system was reduced by $35 million. $490 thousand was saved in annual operating expenses.

Details of the demo / pilot:

Trinity River Authority, Dallas, Texas USA
Application – Biological Nutrient Removal
Rated Capacity – 162 MGD

Hypothesis: As we adopt lower aeration operation, ecology will shift and nutrient removal capacity will not be be decreased.

Action: Gradually progressed from 2.0 mg/l to 0.2 mg/l dissolved oxygen (DO) operating conditions over 5 years in 4 aeration basins.

Result: Metagenomic analysis by Microbe Detectives confirmed the hypothesis to be true. Commamox (CMX) bacteria emerged and became the primary “workhorse” delivering an improvement in nutrient removal at a super low DO setpoint.

Basin Design Savings: $35 million
Pre-study $50 million estimated
Post-study $15 million actual cost
Operating Savings: $490,000/year
$350,000/year aeration savings
$140,000/year chlorine savings
Operator Confidence: Quantification of ecology shift educated operators

What problem did this solve?

Nutrient pollution is one of the world’s most widespread, costly and challenging environmental problems, and is caused by excess nitrogen and phosphorus in the air and water. Wastewater is a primary source.

TRA Objectives: Optimize process efficiency while not decreasing nutrient removal capacity. Provide operator confidence that low DO conditions selects for a different ecology that provides same nitrification capacity as high DO.

What this means for the future?

BNR optimized by metagenomic analysis can drive transformative gains in design and operational costs, and smaller footprint.