Wastewater dairy lagoon aeration is one method of treating byproducts of dairy processing. One of the benefits of utilizing a lagoon, as opposed to an aeration tank, is the flexibility wastewater lagoons have to accept the varying amounts of flow and BOD that are commonly the result of dairy processing. Having the right aeration system is a critical component to making sure your dairy wastewater lagoon consistently removes the necessary BOD to meet your discharge requirements.
With that in mind, we’ve written this blog as a case study displaying one of the most powerful lagoon aeration and treatment systems we have seen. It was implemented at a dairy wastewater facility in Michigan.
Coopersville is a small town in western Michigan that is home to approximately 5,000 residents.
Recently, a new dairy facility made plans to enter the Coopersville community and planned to send all of its waste through the Coopersville municipal system. This meant the community could expect spikes in BOD from their original 250mg/L to anywhere from 600–2,000mg/L, with occasional, unpredictable “slugs” of up to 4,000mg/L. (For more about the particular challenges of dairy processing wastewater, read our blog, That Dairy Air: Preventing Dairy Wastewater Odor.) While the dairy would positively impact the Coopersville economy, they were facing a mandatory upgrade and expansion of their wastewater system.
The engineers and operators knew that they needed a few things for certain in this wastewater dairy lagoon:
- Proper Mixing—The dairy facility was going to be discharging massive amounts of BOD into the wastewater dairy lagoon. Much of this would be in the form of solids, and in order to avoid huge sludge buildup, there would have to be a complete-mix environment in the wastewater lagoon.
- Efficient Aeration—With huge, unpredictable swings in BOD a certainty, high DO (dissolved oxygen) was a necessity. It would need to keep things running properly during normal times, as well as be equipped to handle the days when BOD came in at 5x the normal amount.
- Retrievability—With such massive influent BOD levels, this system could not afford to be offline for any amount of time. As a result, maintenance would need to be quick, and occur without taking the whole system offline (i.e. draining).
The Wastewater Dairy Lagoon Aeration System They Chose
In order to meet these criteria, Coopersville chose to implement clarifiers and complete-mix dairy lagoons. Triplepoint’s aeration was selected as a means to efficiently achieve high DO levels while maintaining a complete-mix environment.
With Triplepoint’s system they received an aerator that incorporated coarse bubble mixing within a fine bubble design. Discussions with Triplepoint and the Coopersville engineers confirmed that this would achieve turbulent mixing throughout the lagoons, moving up to 7,000 gallons per unit per minute. This would provide the complete-mix water column necessary in order to handle all the high incoming loads and RAS (Return Activated Sludge).
Furthermore, oxygen is supplied efficiently via an EPDM fine bubble tube diffusers, facilitating the digestion of the “slugs.” The aeration system lives at the bottom of the lagoon, with all of its air transported through submerged laterals and flexible weighted tubing. Moreover, this dairy lagoon aerator is portable: By utilizing a float and stainless steel tether, the individual aerators can easily be pulled to the surface for cleaning and maintenance without taking the wastewater dairy lagoon system offline.
“We started up taking raw dairy waste since day one, and the system handled every bit without a violation. That’s phenomenal for a new activated sludge plant, and we still have not had a violation since startup.” Boasts Coopersville’s head operator, “It eats up everything it takes in. It handles the unpredictable ‘slugs’ great,” he continues,
“even with only one [of two] cell[s] in operation.”
Moreover, due to the portable nature of Triplepoint’s aerator design, Coopersville never has to take the system offline for maintenance. “In an activated sludge plant, you have to drain the aeration cells for aerator maintenance… With the [aerators], we just use a boat to clean the membranes or change them out when necessary, we never have to take the cell offline.”
“This plant runs on a staff of only three,” Steve explains. “If you’ve got a good treatment plant that runs excellently, that sure gives you a lot of extra time to do other jobs. People need to know that. This system isn’t a time stealer.”
The utilization of Triplepoint’s aerator resulted in an energy efficient and low-cost wastewater dairy aeration lagoon system that treats extremely high, unpredictable levels of BOD effectively with relatively little maintenance. Due to the system’s lower cost, high flexibility, and less complex operation, it can outperform alternative lagoon aeration systems in terms of aeration efficiency and mixing effectiveness, including Surface Aerators or Fine Bubble Aerators.
Learn more about Triplepoint’s aeration system by downloading our Ares Aeration® Literature. Take your first step toward efficient and effective lagoon aeration today.