Direct Contact Membrane Distillation of Hydroponic Solutions for Recycling of Phosphate and Potassium

Mark J. Wong, Viral Sagar, Mohammad Tarikuzzaman and Joan G. Lynam ()
Additional contact information
Mark J. Wong: Department of Chemical Engineering, Louisiana Tech University, Ruston, LA 71272, USA
Viral Sagar: Department of Chemical Engineering, Louisiana Tech University, Ruston, LA 71272, USA
Mohammad Tarikuzzaman: Department of Chemical Engineering, Louisiana Tech University, Ruston, LA 71272, USA
Joan G. Lynam: Department of Chemical Engineering, Louisiana Tech University, Ruston, LA 71272, USA

Waste, 2024, vol. 2, issue 4, 1-10

Abstract: A critical issue facing extraterrestrial expansion has always been long-term life support capabilities. The large energy requirements to move even small amounts of material from Earth necessitate the ability to reuse and recycle as much as possible, particularly waste. The weight of food supplies eventually starts to limit the length of the expedition. Hydroponic growth systems offer the ability to grow plants, and with them, a miniature ecosystem. This offers the ability to repurpose both carbon dioxide and waste salts such as ammonia and other compounds, such as those found in urine. A major issue facing hydroponic systems is the need to provide a stable water-based nutrient stream. Direct contact membrane distillation (DCMD) was tested for viability as a method of re-concentrating and stabilizing the nutrient-rich water stream. Polytetrafluoroethylene (PTFE)- and polyvinylidene (PVDF)-based polymer hydrophobic membranes were used to separate solutes from water. The DCMD method was tested with the feed stream operating at temperatures of 50 °C, 65 °C, and 80 °C. The results were analyzed using UV-Visible spectroscopy to determine concentrations. The benefits and limitations of the PTFE and PVDF membranes in DCMD were compared. The larger-pore PTFE membranes concentrated solutions effectively at 80 °C, while the PVDF membranes removed more water at lower temperatures, but permitted detectable phosphate ion leakage. Adjusting temperature and flow rates can help maintain stable ion and water transfer, benefiting hydroponic systems in achieving reliable nutrient levels.

Keywords: concentrating; PTFE; PVDF; waste; water purification; nutrients; deep space; Moon (search for similar items in EconPapers)
JEL-codes: Q1 Q16 Q18 Q2 Q20 Q23 Q24 Q25 Q28 Q3 Q31 Q38 Q5 (search for similar items in EconPapers)
Date: 2024
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2813-0391/2/4/27/pdf (application/pdf)
https://www.mdpi.com/2813-0391/2/4/27/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jwaste:v:2:y:2024:i:4:p:27-519:d:1544633

Access Statistics for this article

Waste is currently edited by Mr. Sumail Li

More articles in Waste from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().