Washington, D.C. (January 11, 2011) -- High energy costs are one drawback of making clean water from waste effluents. According to an article in the journal Biomicrofluidics, which is published by the American Institute of Physics, a new system that combines two different technologies proposes to break down contaminants using the cheapest possible energy source, sunlight. Microfluidics – transporting water through tiny channels -- and photocatalysis -- using light to break down impurities – come together in the science of optofluidics.
"These two technologies have been developed in parallel but there have been few efforts to employ the natural synergy between them," says author Xuming Zhang of the Hong Kong Polytechnic University. "Our results showed a dramatic improvement in the efficiency of the photocatalyst."
The researchers fabricated a planar microfluidic reactor, or microreactor, which is essentially a rectangular chamber made of two glass plates coated with titanium dioxide, the active ingredient in many sunscreen lotions. On exposure to sunlight, the coating releases electrons that react with contaminants in the water and break them down into harmless substances. This is the photocatalysis part of the process. The high surface area of the microreactor enhances the ability of the catalyst to capture sunlight. Although the gap between plates is small, Zhang plans to expand the rectangular dimensions to two square meters. "Our current small-scale proves the concept but we are also scaling up the reactor to a throughput of 1,000 liter per hour," he says. If the larger reactor proves effective, many parallel devices might be used to handle industrial water treatment applications.
The article, "Optofluidic planar reactors for photocatalytic water treatment using solar energy" by Lei Lei, Ning Wang, Xuming Zhang, Qidong Tai, Din Ping Tsai, and Helen L. Chan appears in the journal Biomicrofluidics. See: http://link.aip.org/link/biomgb/v4/i4/p043004/s1
Journalists may request a free PDF of this article by contacting jbardi@aip.org
ABOUT BIOMICROFLUIDICS
Biomicrofluidics is an online open‑access journal published by the American Institute of Physics to rapidly disseminate research in elucidating fundamental physicochemical mechanisms associated with microfluidic and nanofluidic phenomena as well as novel microfluidic and nanofluidic techniques for diagnostic, medical, biological, pharmaceutical, environmental, and chemical applications. See: http://bmf.aip.org/
ABOUT AIP
The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world's largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.
Journal
Biomicrofluidics