WATER WORKS
Environmental engineering researchers are finding the answers to sustaining water resources.
Written by Kippra D. Hopper
Life on Earth always has been sustained by plenty of potable water. Having enough of it – both now and in the future – is an issue that transcends time and space. Andrew Jackson, Ph.D., and his Texas Tech University research team are hoping to find the answers to the challenges of adequate water resources.
Scientists from various disciplines, under the umbrella of the Space Science Center at Texas Tech, is combining their knowledge to answer an essential issue for astronauts and space exploration: How can technology and science be used to find ways to provide clean water to the astronauts particularly on long-duration missions? The research team is evaluating the suitability of biological wastewater treatment methods for NASA’s long-duration space missions, an initiative set in 2004 by President George W. Bush.
To undertake these long-term missions to the Moon, to Mars or to the International Space Station, NASA’s scientists must overcome life support issues. Primarily, they must determine how technology can provide enough drinking water for years for humans in space when the original payload has weight limitations. “We take the wastewater that is produced, treat it back to drinking water and then start again,” Jackson says. “We’ve been specifically looking at biological pre-treatment by using microorganisms to treat the wastewater. With treatment, the host processors that finish, or polish off, the water, do not have to use as much energy or consume as many expendables.”
To achieve the desired results, Jackson, an associate professor of civil engineering, and Audra Morse, Ph.D., one of the key researchers on the team, developed the applicability of membrane-aerated bioreactors for wastewater reclamation. The objects look like clear columns filled with various filters and hoses. Additionally, the team is focusing on the fate of pharmaceuticals and surfactants, or soaps, in water and in the development of mathematical models to describe the water reclamation system.
The same issues that astronauts face in space regarding water resources are applicable to similar issues on Earth. Eventually, Jackson insists, humans will be forced to take wastewater and recycle it back to drinking water. “We’re running out of potable water, and we are approaching the end of new sources of drinking water, so we are going to have to start looking at some water sources that we otherwise would not have looked at, and one of those is going to be wastewater. In an area like Lubbock, Texas, right now, there is water, but in 50 or 100 years, we are going to run out and have to look for other resources. We already are talking about using the wastewater for irrigation, so treatment is going to have to occur.”
A major goal for NASA is to take the technology developed for the space environment and apply it to the terrestrial environment. What the Texas Tech researchers, funded through NASA, learn about their recycling technology in space will help scholars on Earth understand how to continue to provide adequate water supplies for both consumption and irrigation, especially in arid and semi-arid areas, such as West Texas. The Texas Tech Water Resources Center has been involved in working to transfer wastewater reclamation technology to residents lacking wastewater treatment in the Green Valley Farms Colonia in San Benito, Texas.
Using microorganisms to clean water is the primary process used to recycle water. “People use hundreds of gallons of water each day in output, for example in using washing machines or showers that dilute some of the waste, the nutrients and the organic matter,” Jackson explains.
While the problems in the space and terrestrial environments may be the same, the technologies required to solve the water issues are dramatically different. In space, scientists face numerous problems, Jackson says, such as the required limited volume that can be taken into space. Secondly, limited or no gravity in space means that all technologies that work on Earth will not necessarily work in space. Thirdly, the water in space has a very high concentration of waste because of the extremely small volume of water generated by each astronaut that is recycled into clean water.
Out in space, wastewater treatment technology may include the use of plants after treating the water in biological reactors for two outcomes: growing plants for food consumption and capturing water vapor transpired by the plants for drinking water. “The plants actually act as a distillation system. The water they evaporate can be condensed and is extremely clean. Because the biologically treated effluent still contains nutrients, NASA is saved from having to ship nutrients into space by growing plants,” Jackson says.
In the plant process, the plants take up the water, the water evaporates, and engineers condense that water. Evaporated water is very clean because all the salts are left behind. In effluent, a major problem is with salts. The Texas Tech researchers specifically are looking at the chive plant. Ellen Peffley, Ph.D., professor of plant and soil sciences, has worked for years with NASA concentrating on how to grow plants in space. Chives are a demonstration plant, and researchers will be branching out to other food crops, especially those plants whose roots can be separated from the tops.
Bacteria, like humans, have to eat and breathe something, generally organic matter. Not finicky, bacteria will eat the undesired organic matter in the wastewater. The nitrates are not originally present in wastewater, but other bacteria prefer to eat ammonium and to breathe oxygen.
“Basically we are providing an environment to allow bacteria to eat organic matter, and in this case, to breathe nitrates as opposed to oxygen. Engineers want to rid the wastewater of salts, nitrates, ammonium and organic matter. We’re getting rid of nitrates and organic matter simultaneously,” Jackson SAYS.
In attempting to address the continuous supply of water for decades and generations to come, Jackson and his team are reflecting upon the future and are addressing the major and real issue of the maintenance of potable water for life on Earth or in space.
Story produced by the Office of Communications and Marketing
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