Ammonia discharge limits are tightening up for Canadian mines. Be ready with a BioCord system
DATE POSTED: January 27, 2021
By June 1, 2021 metal and diamond mines in Canada will need to comply with a new lower discharge limit for unionized ammonia. Over 100 mines will be affected by this revision to the Metal and Diamond Mining Effluent Regulations (MDMER), which sets a federal effluent limit of 0.5 mg NH3/L.
To achieve this new regulation, changes may be needed to a mine site’s wastewater treatment system. But the new ammonia target can likely be reached without the need for complex or costly technology upgrades. Many mine sites use simple lagoon systems for wastewater treatment—in part due to their ease of use and low operating costs—and there are upgrade options that can maintain this simplicity and affordability while also improving ammonia removal.
More nitrifying bacteria = better total ammonia removal
A simple, fixed-film biological treatment system such as Bishop BioCord™ Reactors can dramatically improve total ammonia removal, without significant changes to the way a lagoon is operated. That’s because a BioCord system is designed to enhance the existing lagoon process rather than add another step or sidestream process to the plant.
Unlike moving-bed or submerged-bed biofilm systems, which require additional tanks or cells, BioCord Reactors can be installed directly into the treatment lagoon to provide a massive surface area on which preferred, naturally occurring bacteria can grow. It’s like a condominium for bacteria; made from densely arranged loops of polymer fibers that are suspended from free-standing frames. This enables BioCord to establish a robust population of nitrifying bacteria that is many times greater than what can be maintained in an ordinary activated sludge lagoon.
BioCord isn’t limited to upgrades only. This modular system can also form the foundation for new wastewater treatment plants that are designed as lagoons, tanks or even temporary containers.
High oxygen transfer is critical
Each frame is also equipped with a micro-bubble aeration system powered by a low-energy compressor. This design enables the system to achieve high oxygen transfer to the biofilm for a fraction of the capital and operating costs of a typical blower-powered lagoon aeration system. Oxygen is a critical, and often limiting, parameter for nitrifying bacteria to proliferate, so having high oxygen transfer at a low energy cost is a tremendous advantage.
Once operational, a BioCord system acclimatizes and adapts to the range of pH, temperature and contaminants that it may experience in the mine’s wastewater lagoon, including high levels of ammonia, nitrogen and cyanide.
BioCord testing shows that the system can achieve over 99% ammonia reduction in synthetic wastewater concentrations as high as 750 mg/L. Since the system is modular, the system can be sized to meet the required ammonia target and quickly expanded if conditions change.
Learn more about the Metal and Diamond Mining Effluent Regulations.
Learn more about BioCord Reactors for high strength wastewater treatment.
Contact us to discuss your high strength wastewater treatment needs.
Top 5 things to consider for a lagoon upgrade
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. We’ve compiled a list of important considerations to help you plan a lagoon upgrade that can provide the performance and capacity your community needs at affordable capital and operating costs.
1) Post-lagoon or in-situ treatment process
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.
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.
Learn how BioCord and baffle curtains are enhancing performance at Limoges WWTF
DATE POSTED: October 6, 2020
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.
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.
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.
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.
North Rustico WWTF saves on sludge handling with Bishop Solids Management Solution
DATE POSTED:
The North Rustico WWTF used to haul away as many as three truckloads of waste sludge per week, which was mostly water and cost the town nearly $50,000 annually. So when the PEI town began planning to replace its aging wastewater treatment plant, one of the top priorities was to implement a simple, economically and environmentally sustainable process for sludge management.
The result was the island’s first-ever system to incorporate the Bishop Solids Management Solution, with geotextile bags and specially selected polymers to dewater municipal waste sludge. The process also produces composted, stabilized biosolids that are suitable for land application.
The simple, low-energy approach eliminates costly sludge hauling and enabled the facility to become self-sufficient for sludge management. The success of the project was recognized in 2014 with the Excellence in Water Stewardship Award from the Council of Federation, which is comprised of Canada’s provincial and territorial Premiers.
Read the full case study in Environmental Science and Engineering Magazine.
Learn more about the Bishop Solids Management Solution for collection and dewatering of process sludge.