Pilot Study
Wastewater Treatment Plant
Overview
MICROrganic's Secondary Wastewater Treatment pilot was installed in January 2019 at the Pittsfield Wastewater treatment plant, which has a capacity to treat up to 15 million gallons per day (MGD) with a typical flow of 12 MGD. The pilot treated 10,000 gallons of wastewater daily from the plant's primary clarifier outfall, circulates influent through our reactor for BOD reduction and returns treated effluent to the primary clarifier. The influent strength was about 120 mg/L BOD, which is within the low-typical range for a municipality, while the EPA BOD discharge requirement is <30 mg/L.
The pilot reactor consistently achieved comparable treatment rates to the typical effluent discharge, which is approximately 15 mg/L. Pilot effluent ranged from 5 mg/L to 25 mg/L. Based on data from the first 6 months of operation, MICROrganic is testing increasing influent circulation up to 40,000 gallons per day. Moreover, the plant has a nitrogen mandate.
Municipal Standard and Pittsfield-Specific Energy Metrics
| WWT Energy Use | Annual Megawatt Hrs. | Energy Use per m³ of wastewater |
|---|---|---|
| Low end at 12 MGD | 4,974 | @ .3kwh/cubic meter |
| High end at 12 MGD | 9,947 | @ .6kwh/cubic meter |
| Low end aeration at 57% of total energy | 2,487 | @ .3kwh/cubic meter |
| High end at 57% of total energy | 5,670 | @ .6kwh/cubic meter |
| NYSERDA/Avg. Aeration intensive w/ nitrification (applicable to Pittsfield) | 3,942 | NYSERDA study |
| NYSERDA/Avg. Energy use, Trickling Filter | 460 | @ 2 million gallons |
| NYSERDA avg. energy/fine bubble aeration | 5,840 - 10,950 | 1600 - 3000 kwh/MG |
Pittsfield-Specific Energy Metrics
The City of Pittsfield upgraded Aeration equipment within the last decade replacing their energy-intensive, aging aeration system with a newer energy-efficient system (Fine Bubble Aeration), as well as three high-efficiency blowers.
Fine Bubble technology launched in the 1970s, as an energy-efficient alternative to mechanical aerators and coarse bubble aeration. Today, Fine Bubble Aeration is extensively deployed for both Industrial and municipal waste. It is much more energy-efficient because smaller bubbles (around 2 mm in diameter) stay in the water longer than larger bubbles.
Pittsfield Aeration Equipment
- Pittsfield has three energy-efficient blowers that were installed when they added Fine Bubble Aeration. Each blower has a capacity of 150kw, but are tuned to 120kw.
- The blowers run singly, 24/7, in series (for redundancy).
- Typical flow is 12 MG/Day; with adverse weather, flow can increase up to 15M (plant capacity)
Wastewater Treatment Metrics: General and Pittsfield Specific
General WWT Efficiency Data:
- Average US Municipal WWT energy use is .3 - .6 kWh per cubic meter of Wastewater (264 gal)
- Average aeration treatment for a plant of Pittsfield’s size ranges from 17 - 34 kWh/Day (6,200 - 12,400 MWh annually.
- Pittsfield average treatment rate: 12M Gal/Day (45,425 Cubic Meters/Day)
- Pittsfield’s Fine bubble Aeration Usage is 2880 kWh/day (approx. 1051 MWh annually)
- Pittsfield also deploys a trickling filter system that requires a 100 hp pump, with equivalent power use of 74kw. Energy use from the Trickling Filter represents approx. 650 MWh annually.
- Pittsfield’s total annual Aeration energy use is approx.1700 MWh.
- High flow requires a second pump for the trickling filter - both are deployed above 12MGD (< 10% of days). Deploying the second pump requires about 1800 kW. We do not have a record of deployment of the second pump.
- Assuming 20 days with higher flow, additional energy use would be 72 MWh.
Average Annual Aeration Cost
This estimate excludes the power needed for the Trickling Filter's second pump and power outage costs. Although rare, power outages lead to substantial expenses as generators are deployed to maintain aeration and pumping, costing about $10K per incident (plus generator operation costs, with 50% related to aeration). Three outages would result in an additional $30k in electricity expenses.
1773 MWh
Average Annual Total Aeration Energy Use
$150,000
Total annual energy costs for aeration
Excluding demand charges
Pittsfield pays $.08685 per kWh (in 2019; electricity costs have increased since this pilot).
Unlock the VIVA™ MFC
If VIVA™ MFC were deployed at Pittsfield (or a comparable plant), Aeration power requirements would be less than 160 MWh.
Reduced Aeration Cost by:
85%
(vs. the current Fine Bubble annual energy use of 1050 MWh).