Recovery of Nutrients from Inedible Biomass of Tomato and Pepper to Recycle Fertilizer

Date

2017-07-16

Journal Title

Journal ISSN

Volume Title

Publisher

47th International Conference on Environmental Systems

Abstract

Plants can be used as a source food, oxygen, and help remove carbon dioxide for human life support in space. But to grow these plants will require sufficient nutrients (fertilizer). This fertilizer can be stowed and resupplied, but this imposes a mass cost to the mission. Depending on the crop, a large portion of the biomass will be inedible. This inedible biomass contains various nutrients that can be recycled for subsequent crops, hence reducing the need for imported fertilizer. Previous studies demonstrated that continuously stirred tank bioreactors and composters can be used to retrieve many of these nutrients. This can provide a liquid effluent that is easily used in hydroponic systems. We explored various approaches to achieve more complete recovery of nutrients from inedible biomass, and focused our testing on pepper and tomato leaves and stems. Approaches included water leaching, acid treatment, microbial degradation, photocatalytic oxidation, thermal methods, and various combinations of these. Acid (0.1 M or 1.0 M HCl) pretreatment with contact times as low as 10 minutes proved effective in combination with many approaches. To date, these treatments have not been able to recover more than 70% of some macronutrients regardless of combination of treatments. This recalcitrant inorganic fraction needs additional study to explore cost effective approaches for closing the mass loop for crop growth systems.

Description

Griffin Lunn, Engineering Services Contract, USA
Gary Stutte, Engineering Services Contract, USA
Lashelle Spencer, Engineering Services Contract, USA
Mary Hummerick, Engineering Services Contract, USA
Les Wong, City College of New York, USA
Raymond Wheeler, NASA Kennedy Space Center (KSC), USA
ICES500: Life Science/Life Support Research Technologies
The 47th International Conference on Environmental Systems was held in South Carolina, USA on 16 July 2017 through 20 July 2017

Keywords

Fertilizer, Solid Waste, Leaching, Bioreactor

Citation