Graywater Treatment Using Biofilm Reactors for Water Recycling in Advanced Life Support

Preliminary experiments for the Bio-Regenerative Environmental Air Treatment for Health (BREATHe) system have been conducted. The BREATHe system is part of a multicomponent life support system and is designed to treat contaminated liquid and gas waste streams simultaneously withing a closed life support system. Experiments focused on the BREATHe I system used for treatment of graywater and waste gas from a solids biological treatment process. In this first experimental phase, prototype benchtop reactors were constructed to evaluate surfactant removal. Surfactants, the major component of detergents, are the primary area of concern for graywater treatment. The recirculation rate was varied between 10 and 20 times the influent flow rate to determine the required recirculation rate for 90% COD removal from the influent wastestream. A recirculation rate of 20 times the inflow rate was required for 90% COD removal. Biological growth rate experiments were performed using two commercial laundry detergents (Tide and Cheer). Biological growth was observed in both cases and growth rates increased with increasing concentrations of Tide. Conversely, increases in Cheer concentrations resulted in lower biological growth rates, possibly due to toxicity. Description:8 page