Nitrogen Recovery during Solid Waste Treatment for Advanced Life Support

In the solid waste treatment system of the new NSCORT center funded by NASA to investigate Advanced Life Support (ALS) systems design, microbiological uptake and the fluxes of various forms of nitrogen will be balanced and recycled. The objective of this research project is to effectively treat ammonium rich scrubbed off-gas wastewater from the Sequential Thermophilic Aerobic Reactor (STAR) operation (on the order of 1000 mg/L of ammonium as nitrogen). The selectivity of four zeolites as ion exchange media has been evaluated in batch reactors. Six more zeolites will be assessed and column experiments will be performed on all ten samples with both synthetic feed and wastewater from STAR operation. Chabazite has been found to have a larger cation exchange capacity than three other forms of clinoptilolite already analyzed. All of the zeolites evaluated thus far are modeled well by the Freundlich isotherm model.