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WHEAT LEACHATE AEROBIC BIODEGRADATION: DENITRIFICATION EFFECTS.  R. Colуn and G. Colуn.  Dept of Chemical Engineering, Univ of Puerto Rico, Mayagьez.

     The National Aeronautics and Space Administration (NASA) are developing an Advanced Life Support System (ALS) to sustain life in space during long space missions.  NASA considers the use of hydroponics growth of wheat, tomatoes, peanuts and soy.  Due to the high nitrate concentration of the wheat waste effluent it was necessary to study the possibility of denitrification in ALS. 

     The effect of the inoculum composition and the initial nitrate concentration were studied in order to determine their influences in the denitrification effects under aerobic condition.  Batch pilot plant studies were used for wheat lixiviate bioconversion. 

     The results clearly showed that the only factor that appears to affect the denitrification effects was the dissolved oxygen concentration.  Ammonia and nitrite composition needed to be considered to avoid overestimation of the denitrification effects.  The significant levels of variability are probably due to a variation in the inoculum composition.

     (Supported by NASA:  NAG10-0257.)