The Ovivo AnammoPAQ is a sidestream treatment technology that utilizes the power of the anammox bacteria to treat high-nitrogen concentration sidestreams in a compact, energy-efficient reactor. Sidestreams such as digester supernatants, centrates and filtrates present an unusual challenge of being extremely high in nitrogen concentration, often corresponding to only 1 to 2% of plant wastewater influent flow but contributing up to 30% of the nitrogen load, as these are typically recycled to the head of the plant. This leads to significant pressure on the secondary system, often leading to system upsets (inability to meet permits) or significantly increased treatment volume and energy consumption in terms of aeration requirements, as well as carbon source consumption for denitrification.
Dutch Deammonification
Ovivo and Paques have over 15 years’ experience with successful installation and execution of more than 40 AnammoPAQ sidestream deammonification systems worldwide. Of particular note is the Olburgen sewage treatment plant installation in the Netherlands, which has been in operation for over 10 years. The plant implemented the solution for the treatment of industrial (potato processing) wastewater and municipal reject water. The process train comprised treatment of the reject water, first with a phosphorus removal/recovery process (via struvite precipitation in the Ovivo Phospaq reactor) followed by the AnammoPAQ deammonification process. The system has consistently and stably achieved greater than 80% phosphorus removal and 92% ammonia-N removal at a high influent loading rate exceeding 2 kg per cu m per day nitrogen. By implementing the AnammoPAQ system on site, the plant was able to replace its aging mainstream process with a system that required 17 times smaller reactor volume (5.3 million gal less volume) and saved electric power by approximately 1.5 GWh per year, providing not only significant capital savings, but also a large return on investment via operational cost savings. Further, the recovered struvite from the Phospaq process is being sold by the plant to nearby customers as a substitute for commercial fertilizers and serves as an excellent revenue source for the plant, making it a true resource recovery plant.
AnammoPAQ offers a superior solution for the treatment of nutrient-laden and carbon-deficient sidestreams, thereby offering a specialized system for their management. The process entails energy-efficient and cost-effective ammonia-N removal with the availability of quick and easy modular upgrade options with minimal impact to the main treatment line.
