5 things you need to know about lagoon upgrades

DATE POSTED: December 22, 2020


Wastewater lagoons provide simple, reliable and relatively low-cost treatment for small and medium sized communities. In Canada and the US, there are nearly 10,000 municipal lagoon systems and many more when industrial, agricultural and commercial lagoon systems are included. 

But eventually a community needs to improve the treatment capacity and performance of its lagoon system to accommodate growth, meet more stringent regulatory requirements, or both. While there are many options for technologies that can likely achieve the upgrade objectives, there are several important aspects to consider to ensure that the system aligns well with the current operational process at a price that the community can afford – from capital and operational perspectives. 

1) Sidestream or in-situ technologies?

Moving-bed and submerged-bed systems typically add tanks or in-ground cells to accommodate the new treatment process. Not only does this add to the plant footprint, it also requires additional equipment such as tanks, pipes, pumps and blowers, which can substantially increase capital costs. In-situ systems can be installed directly into the lagoon to enhance treatment capacity without expanding footprint or adding a large amount of supporting equipment. 

2) Energy demand

Blowers can provide lots of air quickly, but the equipment is costly and has high energy demands. Some systems such as MBBR also rely on coarse bubbles from blowers to circulate the carrier media and keep it in suspension, in addition to supplying air to the microbial population. But larger bubbles are also less efficient at transferring oxygen to microbes – much of the air simply bubbles up and out of the process tank. Instead, consider a system that uses low-energy compressors and micro-bubble aeration for significantly higher oxygen transfer and lower, more efficient energy usage. 

3)Ease of operation 

One of the big advantages of wastewater lagoons is that they require little operator attention compared to more advanced mechanical treatment plants. In-situ systems can also share this advantage since they align well with the way wastewater lagoons are typically managed and don’t add complexity or additional processes to manage. 

4) Capital and long-term operating costs

Tanks, media beds, blowers and other equipment can all add capital and operating costs to a lagoon upgrade. Alternatively, in-situ systems use the existing lagoon cell, which can reduce capital costs by as much as 50%. Energy demand for in-situ systems can also be up to 50% lower by eliminating the need to pump wastewater to sidestream process and replacing blowers with low-energy compressors

Installing Bishop BioCord Reactors

5) Customizability 

Like any wastewater system, lagoons can experience variable loading, changing flows, upset and more. Upgrade technologies should be easily adaptable to respond to short- and long-term operating conditions, including anticipated changes to population and regulatory requirements. To achieve this, consider modular systems that can be brought online as needed or easily expanded to accommodate the needs of the community or business. 

BioCord Reactors check all the boxes

BioCord™ Reactors biological nutrient removal gives lagoon operators a simple and efficient way to dramatically increase capacity and performance of a wastewater lagoon or conventional activated sludge plant without expanding footprint. This low-energy, self-regulating process is ideal to help a plant achieve up to 99% ammonia reduction in difficult treatment conditions such as during cold weather or when experiencing high-strength or variable loading. The fixed-film, modular process is like a condominium for bacteria on which preferred, naturally occurring bacteria can thrive. BioCord reactors offer a flexible, modular design that can be customized to fit virtually any secondary treatment process and handle anticipated flow and loading parameters. 

Learn more about BioCord Reactors for lagoon upgrades. 

Contact us to discuss your wastewater treatment plant upgrade. 

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Learn how BioCord and baffle curtains are enhancing performance at Limoges WWTF

DATE POSTED: October 6, 2020


Flow of WW through baffle curtains and BioCord Reactors at Limoges WWTF

Baffle curtains now surround two cells of BioCord™ Reactors that were installed as part of an upgrade for the Limoges WWTF in The Nation Municipality. The baffle curtains are an important component to maximize contact between the raw wastewater in the lagoon cells and the BioCord biofilm that breaks down the ammonia.

The baffle curtains achieve this by forming a raceway that directs the flow of wastewater through a series of 180 degree turns. This arrangement not only provides the most intensive arrangement for the 30 BioCord Reactors that make up each cell, but also a compact footprint. The two cells will operate in parallel with the incoming flow spilt between them. Each cell is designed to reduce influent ammonia from 30 mg/L to 1 mg/L in the summer and 5 mg/L in the winter.

Treatment lagoons typically struggle to achieve ammonia removal in the winter months, when cold temperatures reduce the population and activity of nitrifying bacteria. The BioCord system, along with other upgrades to the facility, will enable the Limoges WWTF to improve cold-weather performance and alter its operation from intermittent to continuous discharge. These process changes will also provide a dramatic increase to its treatment capacity, increasing it from 1,500 m3/day to 3,500 m3/day.

Limoges BioCord Installation
BioCord Reactors shown during installation. Once the BioCord Reactors were set in place and connected to the aeration system, the baffle curtains were raised into place to create the raceway.

As a result of this $10 million project, which also includes screening, grit removal, disk filtration and UV disinfection the Nation Municipality can extend the life of its wastewater lagoon system and avoid the need to replace it with a costly mechanical treatment plant.

BioCord Reactors are a made-in-Canada solution that is tested and proven to provide low-energy, self-regulating nutrient removal throughout the wide range of seasonal operating conditions that a plant experiences. The easy-to-operate system aligns well with the way wastewater lagoons are typically managed. With an optimized BioCord system, wastewater lagoons can accept greater nutrient loading, decrease retention times and improve effluent quality—especially in cold-weather conditions.

Watch our webinar series or visit our website to learn more about Bishop BioCord Reactors for enhancing cold weather performance in municipal and industrial wastewater lagoons and conventional activated sludge systems.

Contact us to discuss a BioCord system to achieve year-round enhanced ammonia removal in your wastewater lagoon or CAS plant.  

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BioCord Reactors set to provide enhanced ammonia removal for Limoges WWTF

DATE POSTED: July 30, 2020


Bishop BioCord™ Reactors are in place at the lagoons of the Limoges WWTF as part of a $10-million project, designed and managed by R.V Anderson Associates Limited, to upgrade the plant’s capacity and performance. The simple, low-energy BioCord Reactors, in combination with other upgrades, will enable the Limoges WWTF to achieve enhanced ammonia removal in cold-weather conditions and alter its operation from intermittent discharge to continuous discharge. 

Once the upgrades and operational changes are in place, the Limoges WWTF will more than double its rated treatment capacity, increasing from 1,500 m3/day to 3,500 m3/day. As a result, The Nation Municipality can extend the life and capacity of the Limoges WWTF to accommodate community growth and avoid the need to build a complex mechanical treatment plant, which would come with higher capital and operating costs. 

Sixty BioCord Reactors were installed this month, by general contractor Thomas Fuller Construction,  into two new lagoon cells that were created by dividing a large existing cell. Baffle curtains will be installed next, to direct wastewater through a channel that provides maximum contact with the BioCord media and prevents short circuiting. Each BioCord Reactor will also be connected to an air manifold that will power its integrated microbubble aeration system, which provides mixing and high oxygen transfer to the biofilm.

BioCord advantages

The BioCord system uses strands of densely arranged loops of polymer fibers suspended from free-standing frames to provide a massive surface area on which preferred, naturally occurring bacteria can grow. This attached-growth process offers many advantages that include low energy requirements, simple operation and maintenance and resistance to washout during high hydraulic loading. 

A close up of a BioCord Reactor shows the BioCord media prior to installation (left) and after a robust, concentrated biofilm of preferred microorganisms has been established (right).

With an optimized BioCord system, wastewater lagoons can accept greater nutrient loading, decrease retention times and improve effluent quality—especially in cold-weather conditions, when treatment typically becomes more difficult for conventional lagoon systems.

We are grateful for the dedication and teamwork of our project partners, RV Anderson Associates Ltd. and Thomas Fuller Construction, to deliver the largest BioCord project to date for a wastewater lagoon upgrade. 

Watch for more information and more photos from this exciting BioCord project in future issues of our e-newsletter. 

Watch our webinar series or visit our website to learn more about Bishop BioCord Reactors. 

Contact us to discuss a BioCord system to achieve year-round enhanced ammonia removal in your wastewater lagoon or CAS plant.  

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