Development and standalone testing of a gravity dependent biological reactor
| dc.contributor.committeeChair | Jackson, Andrew | |
| dc.contributor.committeeMember | Millerick, Kayleigh | |
| dc.contributor.committeeMember | Gray, Evan | |
| dc.creator | Harkins, Christian David | |
| dc.date.accessioned | 2021-01-25T17:37:50Z | |
| dc.date.available | 2021-01-25T17:37:50Z | |
| dc.date.created | 2020-12 | |
| dc.date.issued | 2020-12 | |
| dc.date.submitted | December 2020 | |
| dc.date.updated | 2021-01-25T17:37:52Z | |
| dc.description.abstract | Long-duration human spaceflight relies upon recovery of potable water from the wastewater produced during interplanetary missions. For long-term human missions to Mars, a recovery of greater than 98% of potable water from wastewater is the goal of wastewater treatment. This research project demonstrates the use of a Membrane Aerated Biological wastewater Reactor (MABR) as a means to effectively treat space based wastewater to conditions necessary for direct reuse treatment through an Integrated water Recovery Assembly (IRA) in order to produce potable water without the need for chemical stabilization and extensive post distillation treatment as conducted on the International Space Station (ISS). The newly developed system is composed of a gravity dependent MABR (referred to as gMABR or MABR throughout) that serves as the collection tank for all waste streams (ISS, Early Planetary Base (EPB), and Transit) and removes dissolved organic carbon (DOC). This new system also stabilizes the organic Nitrogen (N) by biologically oxidizing it to Nitrogen Oxides (NOx-), which reduces the pH of the waste stream. The IRA as an independent treatment option is incompatible with free Ammonia (NH3) and cannot remove some low molecular weight organics. Integrating the two systems provides a sustainable water recovery system. The research objective is to demonstrate that a MABR can operate with variable volume, allowing on-demand loading and production of effluent compatible with the IRA. The project team designed a MABR for EPB wastewater. The system contains a 0.123 m3 tank containing four self-contained independent membrane modules with a specific surface area of 8.82 m2. The MABR receives wastewater (laundry, shower, hygiene, and urine) as generated during the 16-hour wake cycle, and continuously receives humidity condensate (HC). The system discharges the accumulated volume (~14.8L) once per day, prior to the wake cycle. The system was continuously operated for 16 months. During its operation, the MABR was monitored for pH, dissolved oxygen (DO), DOC, total nitrogen (TN), and NOx, daily and less frequently for total ammonium. The MABR system was tested for loadings of one and 1.25 crew-day of an EPB wastewater with both pulse and continual feeding regimes. The reactor removed 76.6% of the TOC reduction and oxidized 51.8% of the organic N. The treatment provided wastewater with a pH of less than five. There was no clear impact of continuous versus pulse feeding on reaction rates or treatment efficacy. | |
| dc.format.mimetype | application/pdf | |
| dc.identifier.uri | https://hdl.handle.net/2346/86659 | |
| dc.language.iso | eng | |
| dc.rights.availability | Unrestricted. | |
| dc.subject | Biological | |
| dc.subject | Wastewater | |
| dc.title | Development and standalone testing of a gravity dependent biological reactor | |
| dc.type | Thesis | |
| dc.type.material | text | |
| thesis.degree.department | Civil and Environmental Engineering | |
| thesis.degree.discipline | Civil Engineering | |
| thesis.degree.grantor | Texas Tech University | |
| thesis.degree.level | Masters | |
| thesis.degree.name | Master of Science in Civil Engineering |