A 1999 R&D 100 Award winning technology, the Ammonia Recovery Process (ARP) is a revolutionary new process technology designed to recover ammonia from dilute waste streams for subsequent resale to global market in the form of ammonium sulfate, ammonium phosphate or liquid ammonia.

ARP Process Description

The ammonia laden solution is first pumped to ammonia adsorption columns where the ammonia is "pulled" from the water by specially prepared ion exchange resins loaded in the columns. A solution of zinc sulfate and sulfuric acid regenerates the ion exchange columns, flushing the regeneration solution to an evaporator where it is concentrated to approximately 60,000 parts per million (ppm). This concentration is then cooled until zinc ammonium crystals form. These crystals are then collected and roasted to drive off the ammonia, which is captured in a packed bed sulfuric acid scrubber where ammonium sulfate forms. The recovered ammonium sulfate crystals are dried, bagged and shipped to wholesale markets worldwide. Ammonium phosphate can be made by altering the type of acid used in the front end of the regenerating process.

ARP Fertilizers will be shipped to markets worldwide.

The only inputs to this process are ammonia laden wastewater, sulfuric acid and energy. The outputs are ammonia free waste and a useful commodity.

ARP can be used as a stand-alone technology, recovering ammonia from a variety of municipal, agricultural and industrial waste streams. When combined with the STORS process, they allow municipal wastewater plants to achieve a zero discharge profile, while reducing the overall cost of operations.

The ARP process recently concluded a highly successful large-scale field demonstration at the Oakwood Beach Wastewater Treatment facility on Staten Island, New York. This project was a joint effort with the New York City Department of Environmental Protection, Foster Wheeler Environmental Corporation, the United States Environmental Protection Agency and the Civil Engineering Research Foundation ( the final report is available for download at www.cerf.org/evtec/news/reports.htm). ThermoEnergy, along with its joint venture partner, Foster Wheeler Environmental Corporation, is now actively commercializing the ARP process.

The STORS/ARP process concept is covered by several separate patents issued within the United States, as well as over thirty foreign countries, with other patents pending.