Researchers at the University of Abertay Dundee (UAD) have discovered that activated carbon cloth is very effective at filtering harmful compounds out of air and liquids. The material was first developed in the 1980s, to protect British soldiers from chemical attacks. It is still in use today, in chemical, biological and radiological warfare suits for the military. This recent study, however, indicates that it could have a number of other uses.
The initial phase of the latest research was carried out in conjunction with Carbon Filter Technology, a Scottish company that manufacturers carbon cloth. The UAD researchers found that the material can be used to create reactive chemicals known as hydroxyl radicals. These are highly unstable, so they react instantly with any pollutants, even at concentrations of a few parts per million.
When combined with ozone gas, it becomes an even more effective filtration medium. “The fabric has countless tiny pores which absorb the organic molecules onto the surface via weak Van der Waals forces,” explained Carbon Fiber Technology’s Ian Johnson. “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.”
Various uses for the relatively inexpensive cloth are now being proposed. They include using it in hospitals to filter antibiotic and drug waste out of outgoing water, in municipal water treatment systems to keep pollutants from entering rivers, on wound dressings, and as a covering for highly-sensitive equipment.
The research was recently published in the journal Water Science and Technology.