By Chip Bettle, Co‐Inventor & Executive Vice President of Engineering, Absolute Aeration, LLC
The City of Royston is a town located in Northeast Georgia operating a wastewater treatment plant that is comprised of a two‐pond (lagoon) system.
James “Butch” Watson, the city’s water/wastewater superintendent, was challenged to drive down the costs of future dredge events and prevent additional damage that may occur to their liner during a dredge.
In 2011 Absolute Aeration LLC, creators of the Blue Frog patented technology, approached the City of Royston’s leadership team to be the first municipal application in Georgia to install revolutionary technology that utilizes natural processes that enhances in situ sludge digestion (bio-dredging).
Absolute Aeration LLC is an environmental technology firm that utilizes proven natural processes to treat wastewater. Documented results support enhancing natural biological processes as a realistic opportunity to increase the effective treatment capacity of an existing lagoon system and meet effluent discharge criteria while driving down the costs of sludge management. Our design strategy provides cost-effective solutions for lagoon owners to meet discharge standards at a significantly lower investment cost.
Wastewater treatment lagoons are the oldest and most commonly used methods for treating wastewater. Traditional methods to remove biosolids (sludge) from lagoons is typically accomplished by adding chemicals or by mechanical dredging, a disruptive and costly process that can cause damage to infrastructure such as liners, and to the environment. Disposal methods such as application onto farmland or landfilling are running into increased regulatory restrictions and public concerns about what’s contained in the biosolids (sludge). Excessive build‐up of sludge can potentially intensify odors and increase effluent concentrations of BOD, TSS, nutrients like ammonia, and pathogens.
The City of Royston, Georgia Background
The first pond in the Royston treatment system was a well‐mixed aerated system; the second pond has three cells; the first cell was a sludge accumulation cell, the second cell was utilized for stabilization, followed by chlorination and discharge (third cell). All permit requirements were routinely met. Sludge was dredged from the second pond cell once every 3 to 5 years at a cost of $150,000.00 per event. A previous dredging event damaged the liner, costing $125,000.00 to repair (cost is for the repair‐damaged area only).
The Science behind Blue Frog Technology to Bio-dredge In Situ
Absolute Aeration has discovered methods to apply established biochemical science that translates into reliable operating processes for wastewater treatment – moving beyond pilot studies to extensive field testing, and scaling up to practical systems.
The Blue Frog System (BFS) mimics natural bodies of water, keeping the water in three distinct layers employing a three‐step process:
Select for Indigenous sludge digesting bacteria.
The surface is aerated to convert soluble BOD into insoluble BOD.
Clean, thin surface water is redirected to the bottom of the water column to reject floating solids like blue green algae.
Documented Results in Royston:
The City of Royston’s 6-month average results ending in June 2014:
|Monthly Permit Requirements
|Residual Sludge||1.5’(4” of dense biogranules + 14” of low density fluff)|
Google earth picture prior 2011
Google earth picture after 2012
There were five significant issues uncovered and resolved during the project implementation:
1. Sludge digestion (bio-dredging) is at a controlled rate, slow and steady, not fast.
The issue was resolved by changing the rotation of the Cell 1 circulators to slow the process down.
2. Sludge reduction was normal in Pond 2 Cell 1, but not in Cell 2.
3. An industrial client discharged potent antibacterial cleaning compounds all at once. Pond 1 turned black and died.
4. As ancient sludge is turned to gas, previously entombed trash is released.
5. Oxygen addition improved when rising bubbles are released into horizontally radial‐outflowing water.
A joint development for wastewater technology requires three key commitments:
1. A city’s water/wastewater superintendent and a city’s leadership team that is committed to promoting sustainability that results in reducing over-all costs.
2. Two‐way communication and data sharing to understand and be proactive to resolving the issue before a crisis occurs.
3. A continued partnership that results in minimizing ongoing costs long-‐term to achieve project objectives.
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.
For further information, contact Brandi Waters, Absolute Aeration Customer Service Manager at (386) 233.5074 or email: firstname.lastname@example.org.