By Chip Bettle, Co-‐Inventor of the Blue Frog Patented Technology
A Case Study for The City of Davisboro, Georgia
The city of Davisboro is located in Washington County, Georgia. The 2012 census population was 1,793 at the 2013 census. The population includes Washington State Prison, approximately 1,500 prisoners.
The city has a Land Application System (LAS) that is designed to treat 300,000 gallons of wastewater per day. Their treatment system is a two-‐pond system utilized for treatment and storage.
Pond 1: Treatment pond (10' depth)
Pond 2: Holding Pond (12' depth)
LAS permits are different from traditional stream discharge permits in that DO, and ammonia limits are undefined.
The pond system was originally designed to meet the nitrate limitation. The flow process transfers water from the treatment pond to the holding pond at the 8ft level, deep in the anoxic zone, and then sprayed from the 10ft depth to the fields.
This strategy meant that any produced nitrate is biologically reduced to N2 before irrigation. It also meant that the effluent water is high in ammonia (~25mg/l). This had the effect of transferring ammonia to the fields, where soil microbes oxidized the ammonia to nitrate. Field nitrate exceeded the limits in some wells. The effluent was stinky (VFA), irritated the skin and frequently clogged spray nozzles.
The table below reviews the permit requirements, and the 12-‐month average results achieved utilizing the Blue Frog System.
Water clarity is nearly water-‐white at the 8ft pond-‐to-‐pond transfer level. The deep-‐ water clarity occurs because the transfer is made below the photic zone (6ft) where there are no algae.
Picture shows the water quality at the 8-‐foot transfer point.
Yellow Frog's aerators aerate the top 3 feet and have attached growth media to biologically lower ammonia levels to ~9mg/l.
Picture is the Davisboro Pond 1, Cells 1 & 2
A dense bed of granules plus a fluidized bed of immature granules converts TSS into gas. A clarifier section rejects floating algae.
Sediment is made dense (17.2% Total Solids) by worms converting light bacteria into dense worm castings ("top soil").
Recalcitrant solids are made digestible by cavitation-‐formed, free radical attack in the venturi impingement section (83.8% volatile solids).
Surface tension is reduced 17.5%, helping water soak into irrigated land faster. Surface tension also assists the grass crop to uptake water and nutrients from the soil, lowering soil nitrate.
The key to the system working is the development of granules in the sludge layer.
A granule is a spherical biofilm (similar to granules in up-‐flow anaerobic digesters) that converts solid TSS into gas in a multi-‐step, well-‐known, complex process.
The BFS is an all-‐natural process that selects for preferred indigenous species and then distributes them on attached growth media and at the bottom of the water column.
Sludge is turned into gas. Recalcitrant sludge (10.8% total solids), algae and pathogens are attacked by cavitation-‐ produced free radicals. Recalcitrant sludge becomes worm castings (17.2% total solids). Algae and pathogens are pierced by the free radicals and extrude their internal fluids as they die. The fatty 4 portion of their fluid is made into fatty acid soap that reduces surface tension, making the water wetter.
The Gold Frog is a Blue Frog base unit that has a patented fine bubble impingement aeration system attached to it. The impingement aeration system is utilized for clarification because of it unique ability to rapidly oxidize soluble BOD, Lower the specific gravity of surface water, sinks insoluble BOD four times faster, Digest sludge in situ, and meet the permitted Dissolved Oxygen Requirements.
A Gold Frog installed at the point of discharge within a CSTR is utilized for final clarification. This allows clarified surface water to be discharged while solids sink to the bottom for anaerobic digestion. The treated water meets the required permitted limitations and is discharged to the receiving environment.
About Absolute Aeration and their Patented Blue Frog Technology
Absolute Aeration is a technology firm that created the revolutionary patented Blue Frog System (BFS). The Blue Frog System is an innovative, affordable solution that is custom designed for municipalities to meet their project scopes at a significantly lower investment cost.
Our patented technology digests organic sludge in situ; eliminating the annual cost spent to dredge pond systems.
Blue Frog System enhances the natural environment to maintain a healthy lagoon system, increasing the lagoon capacity. Engineered designs meet the regulatory discharge requirements utilizing proven natural biological processes to improve the function of a lagoon system promoting good stewardship.
Absolute Aeration support the claims made and limit a municipalities financial risks by providing performance guarantees.
The Supporting Science behind Blue Frog Patented Technology
Our process begins with a Blue Frog unit placed inside our Continuous Stirred Tank Reactor (CSTR). A CSTR is a engineered floating boom that acts as a flow equalizer, an incubator, and as a selector tank. We place the CSTR above the inflow. The function of the CSTR is to select for sludge digesting bacteria and discharge them at the base of the water column.
Picture taken at the Davisboro in-‐flow is a Blue Frog in a CSTR.
The overall science behind our technology mimics the natural movement of water creating three zones. Layering the lagoons is essential to how our system works to maximize results. Blue Frog creates a thinner less dense surface layer in the aerobic zone, a facultative zone, and all of aerobic activity is condensed down in the anaerobic zone. Solids are digested in the anaerobic zone, reducing odor excursions.
About the author: Chip Bettle is Co-‐Inventor & Executive Vice President of Engineering for Absolute Aeration, LLC, Greeley, CO, USA. Chip is a chemical engineer who utilizes his unique perspective, straddling both science and engineering, to lead Absolute Aeration in process development. Chip designs complex, low cost solutions to meet regulated discharge requirements. As an inventor he has over 35 approved U.S. patents.