Graduation Year

2023

Document Type

Thesis

Degree

M.S.

Degree Name

Master of Science (M.S.)

Degree Granting Department

Biology (Integrative Biology)

Major Professor

Kathleen Scott, Ph.D.

Co-Major Professor

Daniel Yeh, Ph.D.

Committee Member

Valerie Harwood, Ph.D.

Keywords

ECLSS, closed-loop systems, Lunar habitats, hydroponics, reclaimed water

Abstract

As humans set their sights on exploration of the Moon and Mars human focused challenges like providing potable water, supplying nutritious food to the astronaut crew, and managing their waste present themselves. There are no readily available resources on the Moon and Mars, therefore nothing should be considered unusable including the organic wastes (i.e., feces and urine) produced by the crew. Fecal matter is not currently recycled and is treated as solid waste. After collection, it is discarded out of the International Space Station where it is incinerated upon re-entry. This approach will not work on the Moon’s surface. There is currently no plan in place other than fecal storage. Fecal material contains ~75% water and considerable fractions of carbon, nitrogen, phosphorus, and minerals which after stabilization, can be recovered and used to grow food crops. The Organic Processor Assembly (OPA) unit was developed through a collaboration between the University of South Florida and NASA’s Kennedy Space Center by recognizing the need to incorporate fecal treatment and resource recycling. OPA is an anaerobic membrane bioreactor designed to treat the fecal waste of a crew of four astronauts on an early planetary while producing a product water rich with nutrients and minerals.

Described here is a long-duration (600 days) operational study of OPA to evaluate the technology’s capability to treat and stabilize fecal (canine) waste by removal of solids and chemical oxygen demand. The collected effluent was investigated for its ability to support the growth of dwarf Pak Choi plants in vertical nutrient film technique towers. OPA met its objectives by removing 97% of total chemical oxygen demand, 87% soluble, and removing from 97% to 100% of total suspended solids when the influent was compared to the effluent. OPA’s effluent supported the growth of 12 Pak Choi plants, in duplicated trials with no detected Enterococcus in OPA’s hydroponic nutrient reservoir. This thesis research has demonstrated that the novel OPA technology can, under the conditions used herein, offset fecal storage volume, assist in waste management, and recover usable resources.

Download

Share

COinS