Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Spinning CDs to Clean Sewage Water

24.09.2013
Scientists find a potential new use for old music CDs: coating disks in photocatalytic compounds and spinning them to clean water

Audio CDs, all the rage in the ‘90s, seem increasingly obsolete in a world of MP3 files and iPods, leaving many music lovers with the question of what to do with their extensive compact disk collections. While you could turn your old disks into a work of avant-garde art, researchers in Taiwan have come up with a more practical application: breaking down sewage.


Figure 1: This image shows an optical disk entirely coated with zinc oxide nanorods. (Photo credit: Din Ping Tsai, National Taiwan University)


This scanning electron microscope image shows tiny nanorods growing on the disk. (Photo credit: Din Ping Tsai, National Taiwan University)

The team will present its new wastewater treatment device at the Optical Society's (OSA) Annual Meeting, Frontiers in Optics (FiO) 2013, being held Oct. 6-10 in Orlando, Fla.

“Optical disks are cheap, readily available, and very commonly used,” says Din Ping Tsai, a physicist at National Taiwan University. Close to 20 billion disks are already manufactured annually, the researchers note, so using old disks for water treatment might even be a way to cut down on waste.

Tsai and his colleagues from National Taiwan University, National Applied Research Laboratories in Taiwan, and the Research Center for Applied Sciences in Taiwan used the large surface area of optical disks as a platform to grow tiny, upright zinc oxide nanorods about a thousandth the width of a human hair. Zinc oxide is an inexpensive semiconductor that can function as a photocatalyst, breaking apart organic molecules like the pollutants in sewage when illuminated with UV light.

While other researchers have experimented with using zinc oxide to degrade organic pollutants, Tsai’s team is the first to grow the photocatalyst on an optical disk. Because the disks are durable and able to spin quickly, contaminated water that drips onto the device spreads out in a thin film that light can easily pass through, speeding up the degradation process.

The Taiwanese team’s complete wastewater treatment device is approximately one cubic foot in volume. In addition to the zinc oxide-coated optical disk, the device consists of a UV light source and a system that recirculates the water to further break down the pollutants.

The research team tested the reactor with a solution of methyl orange dye, a model organic compound often used to evaluate the speed of photocatalytic reactions. After treating a half-liter solution of dye for 60 minutes, they found that over 95 percent of the contaminants had been broken down. The device can treat 150 mL of waste water per minute, the researchers say.

The spinning disk reactor is small, consumes little power, and processes contaminated water more efficiently than other photocatalytic wastewater treatment methods, Tsai says. The device could be used on a small scale to clean water contaminated with domestic sewage, urban run-off, industrial effluents, and farm waste. Going forward, the team is also working on ways to increase the efficiency of the reactor, and Tsai estimates that the system could soon be improved to work even faster, perhaps by creating layers of stacked disks.

Presentation FW1A, “Zinc Oxide Nanorod Optical Disk Photocatalytic Reactor for Photodegradation,” takes place Wednesday, Oct. 9 at 8:15 a.m. EDT at the Bonnet Creek Ballroom, Salon IV at the Hilton Bonnet Creek in Orlando, Fla.

EDITOR’S NOTE: Images and a video demonstration of the system are available to members of the media upon request. Contact Lyndsay Meyer, lmeyer@osa.org.

PRESS REGISTRATION: A press room for credentialed press and analysts will be located in the Hilton Bonnet Creek, Sunday through Thursday, Oct. 6-10. Those interested in obtaining a press badge for FiO should contact OSA's Lyndsay Meyer at 202.416.1435 or lmeyer@osa.org.

About the Meeting

Frontiers in Optics (FiO) 2013 is the Optical Society’s (OSA) 97th Annual Meeting and is being held together with Laser Science XXIX, the annual meeting of the American Physical Society (APS) Division of Laser Science (DLS). The two meetings unite the OSA and APS communities for five days of quality, cutting-edge presentations, fascinating invited speakers and a variety of special events spanning a broad range of topics in optics and photonics—the science of light—across the disciplines of physics, biology and chemistry. An exhibit floor featuring leading optics companies will further enhance the meeting. More information at www.FrontiersinOptics.org.

About OSA

Founded in 1916, The Optical Society (OSA) is the leading professional society for scientists, engineers, students and business leaders who fuel discoveries, shape real-world applications and accelerate achievements in the science of light. Through world-renowned publications, meetings and membership programs, OSA provides quality research, inspired interactions and dedicated resources for its extensive global network of professionals in the optics and photonics field.

Lyndsay Meyer | EurekAlert!
Further information:
http://www.osa.org

More articles from Process Engineering:

nachricht Diamond watch components
18.06.2018 | Schweizerischer Nationalfonds SNF

nachricht Quick and safe laser joining of steel-aluminum mixed connections
05.06.2018 | Laser Zentrum Hannover e.V.

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>