AnammoPAQ® Process

The AnammoPAQ® process is an elegant shortcut in the natural nitrogen cycle. The process utilizes Anammox bacteria which directly convert ammonium (NH4+) and nitrite (NO2-) into nitrogen gas. Paques developed the original process for commercial purposes in cooperation with Delft University of Technology and the University of Nijmegen. Since the first full-scale plant started up in 2002 (treatment of sidestream from sludge digestion), many other plants have been installed and are running successfully.
  • Centrate
  • Filtrate
  • Digester Supernatant
  • Landfill Leachate
  • High Nitrogen Industrial/Municipal Streams

anammox-installationThe AnammoPAQ® process addresses the need for energy efficient and cost effective solution for treating high nitrogen streams at wastewater plants. These streams such as centrates, filtrates, digester supernatants and landfill leachates constitute just 1% to 2% of the flow at the WWTP but can add 15% to 40% of the Nitrogen load to the main treatment line, significantly increasing the size of the main treatment line along with operating costs, otherwise leading to permit violations. A specialized system such as the AnammoPAQ® thus helps address the above concerns and provides an effective way to treat these streams without disrupting and thereby optimizing the main treatment line.

    • High Loading Rates leading to compact footprint
    • Low O&M Costs
    • Stable and Robust Process
    • High experience and Large reference base
    • Quick startup

High loading rates – Loading rates for AnammoPAQ® systems are the highest in the industry. This leads to extremely small reactors with compact footprints providing large savings on civil and construction costs. Further even at these high loading rates, AnammoPAQ® systems are able to achieve greater than 90% Ammonia-N removal and greater than 85% Total Nitrogen removal.

Low O&M Costs – The AnammoPAQ® system has the lowest energy requirement of any competing deammonification system on the market, helping the client achieve significant savings on O&M, and thereby a significantly quicker return on investment

Stable and Robust Process – AnammoPAQ® systems have been in operation globally for over 15 years and have been tested under various stress load and flow conditions. The easy to operate AnammoPAQ® system has proven its robustness in its ability to respond to such variations by maintaining stable and reliable performance. In fact, none of the installations have needed any reseeding in all their years of operation providing further testament to the technical prowess and fortitude of the system

High Experience and Large reference base – With over 50 installations globally (including municipal and industrial clients), the AnammoPAQ® system has the highest cumulative treatment capacity (greater than 250,000 lbs/d Ammonia removed) of any deammonification system in the world. Having developed the deammonification system process concept for WWTPs itself over 15 years ago, the world renowned experts at Ovivo and Paques thus provide clients with the experience coupled with industry leading technical expertise, all combined with the legendary Ovivo service, for complete peace of mind.

Quick Startup – AnammoPAQ® systems can be started up within 3 weeks providing the quickest startup time of any deammonification system in the market (which often take in excess of 6 months), leading to significant time and cost savings for the client

AnammoPAQ® is a continuous flow reactor system in which nitritation and anammox conversion occur simultaneously in a single process unit. Anammox (anaerobic ammonium oxidation) conversion is an elegant short-cut in the natural nitrogen cycle where ammonium and nitrite are converted to nitrogen gas. As the Anammox process involves removal of ammonium over nitrite (NO2-) rather than nitrate (NO3-), 63% less oxygen (O2) is required while eliminating the need for an external carbon source altogether. Optimal process control ensures retention of AOBs and Anammox bacteria while eliminating NOBs, leading to stable & robust operation.


  • Featured
  • Product Brochure 1

    AnammoPAQ® Process Brochure

    Read more about the AnammoPAQ® process as a sustainable, cost-effective solution to nitrogen removal.

  • White Paper


    Over a Decade of Experience with the ANAMMOX® Reactor Start-up and Long-Term Performance

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