Capture the Most Phosphorus

    CalPrex™ + AirPrex®

    THE PROBLEM

    Phosphorus is a Limited Resource

    Most phosphorus fertilizer used for modern agriculture originates from phosphate rock. Phosphate rock is a non-renewable resource with limited reserves. To ensure sustainable food production for the future, it is critical to expand the recovery and reuse of phosphorus from waste sources. Prior to the development of CalPrex and AirPrex, the methods to effectively recover phosphorus entering a wastewater treatment plant were to chemically acidify sludge or incinerated ash. These processes are prohibitively expensive if only used for fertilizer production.

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    THE SOLUTION

    Maximum Phosphorus Recovery, Minimum Sludge Production

    The combination of CalPrex + AirPrex captures 50%+ total phosphorus entering treatment plants, with minimal addition of chemicals.

    The CalPrex process harnesses the acidogenic bacteria power to acidify bio-P sludge. Over 60% of phosphorus solubilizes in the acid phase digestion process. Dewatering acidogenically digested sludge isolates the dissolved phosphorus (orthophosphates) in the centrate. The centrate is sent to the CalPrex reactor, where orthophosphates are precipitated by calcium hydroxide. By maintaining a pH solution of 6.5 or below, phosphorus is recovered as brushite (CaHPO4· 2H2O), a market-ready, high-quality fertilizer.

    AirPrex converts the remaining orthophosphates in digested sludge to struvite (MgNH4PO4· 6H2O) by air stripping CO2 and adding magnesium chloride. Struvite is another market-ready fertilizer. AirPrex reduces the phosphorus recirculation by 90%.

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    THE BENEFITS

    CalPrex + AirPrex: A Combined Approach

    Icon-CNP-Phosphate
    Reduce Phosphate Recycle Load up to 90%
    Icon-CNP-Polymer
    Reduce Polymer Consumption up to 30%
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    Reduce Disposal Costs up to 20%
    Icon-CNP-Maintenance
    Reduce Maintenance Costs up to 50%
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    Recover Over 50% of Total Phosphorus
    The CalPrex™ Technology is licensed by Nutrient Recovery and Upcycling LLC.
     
    Available Literature

    Process

    CalPrex + AirPrex

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    Company

    Resource Intensification

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    Bio

    CNP Company Backgrounder

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