But the biowall is not just for show. It is an active living filter that removes volatile organic compounds (VOCs) from the air. Scientists and students at Drexel are studying the biowall and the plant and microbe communities responsible for its air filtration properties to get a better understanding of how it works.
Dr. Michael Waring, an assistant professor in the College of Engineering who specializes in indoor environmental engineering, will focus on the chemical and physical aspects of the living wall, while two biology faculty members from the College of Arts and Sciences, Dr. Jacob Russell and Dr. Shivanthi Anandan will focus on the wall’s biological functions.About the Biowall
Drexel’s biowall consists of over 12 different varieties of tropical plants that grow in the absence of soil. The plant roots are embedded between two layers of woven, porous material similar to that of a kitchen scrubbing pad. Water trickles down the wall between these layers, providing plant roots with nutrients and hydration. The water is also key to filtering the air: Fans running behind the wall continuously pull contaminated indoor air through the biowall’s porous materials. As a result, VOCs naturally dissolve into the water and become available to bacteria and fungi on the plants’ roots. These microbes then consume and break down the VOCs into benign products, primarily carbon dioxide and water. As the microbes remove VOCs from the water, more VOCs can be absorbed from the circulating air, and the cycle continues. According to estimates by NEDLAW Living Walls, the company that designed and installed Drexel’s biowall, the wall is capable of generating between 16,000 and 30,000 cubic feet of ‘virtual’ outside air per minute.
While scientists have measured the overall results of this air filtration mechanism in biowalls, Waring points out that such measurements are coarse – measuring only the total concentration of VOCs in the air before and after passing through a biowall. Researchers don’t yet know specifically which chemicals are or are not being filtered out, while few have studied the microbes in plant roots that are responsible for breaking down VOCs. These are exactly the questions the Drexel team plans to address.Drexel’s Biowall Research
In their laboratory apparatus, the researchers will suspend plants’ roots inside a chamber and measure the concentrations of chemicals in air flowing out of the chamber. Waring will then compare these measurements to samples taken from full-scale work on the biowall itself, using air samples drawn from each of eight sampling ports built into the back of the wall for research use. In their biological studies, described in more detail below, Russell and Anandan will compare the microbial communities in the model system with those found on the biowall.
“One of the really exciting things about this project is that we can test what the wall does in a real building rather than just presume that it works as well as it’s supposed to,” Waring said.Studying Microbial Communities in the Plants’ Roots
The researchers will expose microbial communities to various types of chemicals in the aeroponic system in the lab. “We’re looking to see, when exposed to a particular chemical, do particular microbes proliferate?” Russell said.
To identify the microbes, Russell’s team will perform a kind of molecular barcoding to identify them by their DNA. The bar codes are much like a DNA fingerprint, but “instead of trying to match samples from a crime scene to an individual, we’re looking at a small microscopic community to understand everything that’s living there,” Russell said.
Russell will eventually examine not just what genes are present in the microbe communities, but what genes are actually expressed as the chemical environment changes. It is possible that microbes can turn on helpful genes when exposed to VOCs that help break down the chemicals more quickly.
While Russell’s work will help identify which microbial communities are present on the plants’ roots, Anandan will build on that effort by attempting to identify which specific microbial species or microbial communities are responsible for breaking down VOCs in the biowall.
Hundreds if not thousands of species of microbes may exist on the plants’ roots, but not all are actively involved in breaking down VOCs. According to Anandan, it is likely that a consortium of microbe species is responsible for the breakdown of chemicals, like “a conveyor belt of microbes, each with a specific step of breakdown.”
Anandan will cultivate living microbes in the lab and work to identify which microbes are active in these conveyor belts and what molecular processes they use to break down VOCs. Ultimately, it may be possible to grow populations of VOC-consuming microbes to use as a treatment on the roots of biowall plants that need a boost.A Truly Integrated Sciences Building: Biowall Research in Building Design and Hands-On Education
Drexel’s biowall was designed and installed by NEDLAW Living Walls in collaboration with Toronto-based Diamond and Schmitt architects, who designed the building. Waring and other Drexel faculty members collaborated with the designers and architects to ensure that the physical structures of the building were fully compatible with their plans for research on the biowall. Eight sampling ports at locations behind the biowall, where researchers can collect air samples to measure the concentration of chemicals, were built into the structure to Waring’s specifications.
Biowall research is also integrated with hands-on education in the new building: Both Russell’s and Waring’s labs employ Drexel students through the University’s co-operative education program. The students work full-time as lab employees conducting hands-on research on the biowall and its plants and microbes.
Many of the science faculty at Drexel are integrating biowall science into the curriculum. Anandan said she incorporates the biowall into her instruction of freshman students. “This is biology in action,” Anandan said. “What you’re seeing is a biological application in real life, coupled with engineering, that works to do something that we think is going to improve human health.”
Learn more about the Papadakis Integrated Sciences Building at http://www.drexel.edu/now/professionals/releases/archive/2011/September/Drexel-Opens-Nations-First-University-Facility-with-Biowall/
Rachel Ewing | Newswise Science News
Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Life Sciences
17.10.2017 | Earth Sciences