Ordinary-looking fabric can be used to filter out and destroy incredibly toxic materials, even when they're only present in tiny amounts, according to new research at the University of Abertay Dundee.
The research team found that activated carbon cloth -- which was originally developed at the Porton Down military research facility -- can be used to create extremely reactive chemicals called hydroxyl radicals. These are so unstable they instantly react with any pollutants, even at tiny concentrations of just a few parts per million.
This inexpensive material could be used on a small-scale in hospitals to filter out waste, or on a massive industrial scale to remove hard-to-detect chemicals that kill essential bacteria in our water system and risk human health.
Professor David Bremner, Chair of Applied Environmental Science at Abertay University, said: "There's been a lot of research into how activated carbon in powder or grain form can be used, but what we found is that using it as a fabric has a number of real advantages.
"There are many applications -- from a hospital to an industrial chemical plant -- where activated carbon cloth could be used to make incredibly sensitive filters, removing dangerous or unpleasant molecules even at very low concentrations.
"We also discovered that using activated carbon cloth in conjunction with the gas ozone (O3) removes even more potentially dangerous organic content. This really is a step forward for the safety of waste treatment, and we're now working on developing more practical applications for this fascinating fabric."
The initial work was carried out as a knowledge-transfer partnership (KTP) with Carbon Filter Technology, a Kirriemuir-based company which produces different versions of the material which may be used for medical clean rooms, air and water filtration, and highly advanced wound dressings.
Company Director Ian Johnson explained the science behind the research: "Activated carbon cloth can effectively remove contaminants from the air, gas or liquids such as waste water.
"The fabric has countless tiny pores which adsorb the organic molecules onto the surface via weak Van der Waals forces. The pollutants then react with the oxidant (ozone) on the surface of the carbon cloth, converting them into smaller molecules or even carbon dioxide and water. The carbon cloth is really acting as a catalyst, promoting the decomposition of the pollutants."
He added: "The applications we're developing with Abertay University are very exciting, and it's great to be involved with a university that prides itself on working directly with businesses in real-world, applied settings. Hospital patients and industrial companies could both really benefit from this important research."
The original work on activated carbon cloth at Porton Down in the 1980s was focussed on developing a material that could protect soldiers from chemical attacks. Today one of the more recognisable uses for the fabric is the inside of chemical, biological and radiological warfare (CBR) suits for the military.
Some of the other problems that could be solved using this technology include removing drugs like antibiotics from waste before they enter the sewage system, removing unpleasant odours from ostomy bags in hospitals and care homes, or for use as highly absorbent material to protect sensitive equipment.
The research was recently published in the journal Water Science & Technology.
- Rashmi Chand, Raul Molina, Ian Johnson, Anna Hans, David H Bremner. Activated carbon cloth: a potential adsorbing/oxidizing catalyst for phenolic wastewater. Water Science & Technology, 2010; 61 (11): 2817 DOI: 10.2166/wst.2010.091
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