Phosphorus Removal System Offers Recovery Option

June 29, 2017
Struvite production can provide users with new revenue stream

The Ovivo Phospaq is a system for phosphorus removal and recovery in high concentration streams, such as municipal sidestreams and industrial effluents.

High phosphorus concentration streams—such as centrates and filtrates—can lead to significant operational and process problems at wastewater treatment plants, particularly those with biological phosphorus and/or thermal hydrolysis process. Therefore, it becomes critical to remove this phosphorus to protect onsite equipment and reduce maintenance costs. While it is possible to remove the phosphorus chemically, the demand for these chemicals can be significant, adding to the utility’s operational budget. Further addition of these chemicals can remove alkalinity from the streams, leading to the need for additional chemicals (alkalinity) adding to the plant’s operating expense.

The Phospaq process offers a complete solution with its ability to address all the above client concerns while also providing the option of recovering the phosphorus in the form of a slow release fertilizer—struvite. The Phospaq is an elegant process comprising an aerated reactor with coarse bubble diffusion and a specialized struvite separation/recovery mechanism. Magnesium oxide is added for struvite precipitation while also adding alkalinity, thereby aiding downstream biological treatment processes. The aeration provided for agitation also helps strip out carbon dioxide from the influent, thereby increasing the pH and aiding struvite crystallization. The aeration further provides free biochemical oxygen demand removal along with sulfide oxidation, which helps reduce heterotrophic competition and sulfide inhibition in downstream (deammonification) systems. Thus, the Phospaq provides a comprehensive solution for utilities looking to address phosphorus/struvite issues at their plant while also providing a potential revenue source through sale of the recovered phosphorus fertilizer.

With multiple operating installations and more than a decade of operational data and experience, the Ovivo Phospaq system provides a robust and cost-effective solution for phosphorus removal and recovery.

Image courtesy Institute of Chemical Research of Catalonia (ICIQ).
All images courtesy of Ecosorb.