ARTICLE
BioCord® pilot system demonstrates MDMER ammonia compliance for Canadian gold mine
At the end of 2021, we began analyzing data from a BioCord® Reactor pilot system that had been running at a gold mine since August. The project’s objective was to show that a low-energy, fixed-film BioCord system could improve ammonia removal for the onsite wastewater lagoon system and help the mine maintain compliance with the Metal and Diamond Mining Effluent Regulation (MDMER). Changes to MDMER came into effect in June 2021 and set a new, stronger federal effluent limit of 0.5 mg N/L for unionized ammonia.
Our BioCord pilot system didn’t disappoint us or the client. Our team tested the system using influent from two different wastewater sources, with average ammonia concentrations of 4.8 and 22.3 mg/L. Over the four months that the containerized BioCord system ran, it consistently achieved the 0.5 mg N/L regulatory requirement and removed up to 80% of the influent ammonia—even when the water temperature was as low as 0.5⁰C.
More nitrifying bacteria = better ammonia removal
Temperature is an important consideration, since the bacteria that provide ammonia removal are temperature sensitive and under cold conditions become less active and therefore less effective. As a result, the wastewater lagoons at many mines, and other industrial sites, struggle to achieve the required ammonia target during the winter months.
BioCord solves that problem by developing a robust, stable biofilm that remains productive under cold conditions. The pilot system even experienced high loading of heavy metals, which can inhibit nitrification and ammonia removal. However, despite that challenge, the BioCord system continued to perform well and maintained a high ammonia removal rate.
Full-scale systems can be quickly and cost-effectively installed
A full-scale BioCord Reactor can be installed directly into the treatment lagoon – often while it remains in operation. Our engineers design the system based on the incoming ammonia load and the desired removal rate. BioCord’s in-situ design offers a big advantage over sidestream systems, such as MBBR, because BioCord avoids the additional cost and operational oversight associated with the tanks, blowers, pumps and consumables of those alternative systems. BioCord’s modular design also enables it to be easily expanded, simply by adding more media to the lagoon to handle higher loading or removal rates.
