Compressed earth blocks (CEBs), like those used on a project in Midland, Texas, in 2006, can allow housing to be made almost entirely of local materials. A research team at the University of Oklahoma was awarded $90,000 to test a home built using CEBs against a conventional but energy-efficient wood-framed home. Wikimedia Commons
Civil engineering projects that focus on sustainability are among the 15 winners of the 2012 EPA P3 Awards selected from among entries submitted by 300 university and colleges.
May 15, 2012—Research projects to test the performance of a structure constructed from compressed earth blocks (CEB), refine a portable, solar-powered water treatment system for disaster areas, and further develop a natural wetlands for small business gray water treatment were awarded grants from the U.S. Environmental Protection Agency (EPA) recently as winners of the eighth annual People, Prosperity, and Planet (P3) competition.
More than 300 university and college teams brought projects to the National Sustainable Design Expo in Washington, D.C., in April. An initial peer review produced 45 finalists from which 15 winners were selected following two days of judging by a panel of experts.
A research team at Embry-Riddle Aeronautical University was awarded a $90,000 grant to further miniaturize and refine a portable water treatment system that fits into an specially designed backpack and is powered by folding photovoltaic panels.
“After the Katrina disaster, I challenged my civil engineering seniors to design a portable water treatment system that would be capable of taking post-Katrina polluted water and make it potable,” Mark Fugler, Ph.D., P.E., said in written comments to Civil Engineering online. “The system had to be able to perform at any location on earth at any time of year, be completely assembled and operable in two hours, be capable of providing sufficient drinking water for 500 people, and be capable of operating for 30 days with only minor maintenance tasks.”
Fugler, a professor who chairs the university’s civil engineering program, said the product of that original challenge was designed to fit into a standard footlocker. Mechanical engineering students joined civil engineering students recently in making the system smaller and lighter.
“The backpack system is completely powered by a deep-cycle battery that can be recharged using portable folding solar panels,” Fugler said. “The system uses standard residential water filtration components combined with a supplemental bacteria-removal, ultraviolet light treatment chamber. All of the components are ‘off the shelf’ and easily replaced.”
The team will use the grant to update the pump and power systems with the latest technology and develop a system to remove silt from influent to minimize operator effort, Fugler said. The backpack currently weighs about 70 pounds and would cost $2,000 to reproduce. Disaster relief agencies and the military are interested.
“Aside from the feeling of self-satisfaction from receiving the award, the funds will help take the project to the next level,” Fugler said. “Using custom-designed parts financed through the EPA grant, it is possible that the size and weight of the system can be significantly reduced while the efficiency could be greatly improved.”
A research team at the University of Oklahoma was awarded a $90,000 grant to design, test, and construct a house built utilizing CEBs made from a mixture of sand and clay placed into molds in a hydraulic machine and compressed into a dense brick or block. The CEB house will be sited adjacent to a conventional, energy-efficient frame house. Both will be equipped with instrumentation and tested. The houses will be constructed in Norman, Oklahoma, in partnership with the Cleveland County Habitat for Humanity.
“There are many excellent reasons for using CEBs,” said Charles W. Graham, Ph.D., AIA, a professor who is also the dean of the college of architecture, in written comments to Civil Engineering online. “They are much quieter. They offer thermal flywheel effects that are desirable from an energy efficiency standpoint. They are also easy to repair if damaged. In areas with military unrest, these walls are so thick and absorb so much energy, they are often used as shelters.
“Our research program is focused on long-term, comprehensive results,” Graham said. “The award from the EPA will allow us to build a CEB house next door to an energy-efficient wood-framed house and do a side-by-side comparison for at least a year. Energy performance, occupant comfort, and other attributes of CEBs will be studied.”
Researchers believe adoption of CEB construction would reduce greenhouse gases, the carbon footprint of construction, energy consumption, and dependence upon imported materials, according to Lisa Holliday, Ph.D., P.E., an assistant professor who is working on the project.
“U.S. housing is a major market; any small change can have a huge effect,” Holliday said in written comments to Civil Engineering online. “Compressed earth blocks can allow housing to be made almost entirely of local materials and therefore reduce the use of natural resources and the transportation associated with housing.”
The team has completed the first phase of the project, having developed a CEB soil mix design, laboratory tested CEB samples, built and tested full wall assemblies to determine their properties and constructability, and developed the research protocols for instrumenting and analyzing the conventional and CEB houses.
“We are learning a lot about containment of the CEBs during earthquakes. These results can be translated into structural advancements for hurricane and tornado resistance,” Graham said. “Our work in mortars and plasters is also yielding some unique results. We have a unique bond beam design we now use at the top of the wall because we found a way of doing them that had, to our knowledge, never been used before. We have also taken a look at the rubble foundation systems used in some parts of the world and are making improvements in it.” (Read “Haitian Rubble Homes Offer More than Just Shelter” on Civil Engineering online.)
Researchers at Appalachian State University also received a $90,000 grant to continue development of an indoor, point-of-use artificial wetlands they believe will be suitable for recycling gray water from small businesses for immediate reuse to operate toilets. In the first phase of the project, researchers utilized a converted treatment system used in an earlier project designed to treat biodiesel waste wash.
Researchers at Appalachian State University are developing an
indoor, point-of-use artificial wetlands they believe will be suitable
for recycling gray water from a hair salon for immediate reuse to
operate toilets. Courtesy of Appalachian State University
Researchers utilized gray water from a local hair salon—Haircut 101, in Boone, North Carolina—which was chosen in part because the business generates abundant gray water. Separating the gray water from the minimal black water produced by such a business greatly reduces the volume of wastewater sent for treatment to a wastewater treatment plant.
“I am a hairstylist and realized that we were literally pouring hundreds of chemicals and water down the drain every day,” said Bobbie Jo Swinson, an appropriate technology major working on the project, in written comments to Civil Engineering
online. “I wanted to see if the numerous studies I was reading about phytoremediation would work for a small indoor system.
“At this point in our research we are testing many species of plants with salon water to see if and how much contaminants are removed [by the] plants alone,” Swinson said. “We anticipate that gray water from the salon will collect in a storage container and then be circulated through the hydroponic plant system before a final filtration stage that is to be determined by Phase II. We are looking at various bryophytes (mosses), ceramic filters, and biochar for this final filtration stage. After water passes through final filtration it will enter a holding tank to be used for toilet flushing (and eventually as building codes allow, laundering).”
Swinson said that although salons are the major focus of the team’s research, the technology can be applied to other businesses and has the potential to help alleviate strained water supplies in developing countries.
“This process will save about 35,000 gallons of water from being drawn from municipal water supply for Haircut 101,” Swinson said. “This number depends on the business itself, but has the potential to save a lot of money for a small business owner.”
A complete list of winning projects can be found at the EPA’s website for the awards