[NEW DELHI] Fibre from the stem of the banana plant can efficiently absorb oil spills that pollute coasts and threaten marine life says a new study by Indian researchers.
Banana fibre, when treated with certain chemicals, can absorb up to 18 times their weight of oil, according to the study published last month (16 September) in the online journal, Carbohydrate Polymers.
Scientists at the Institute of Chemical Technology (ICT), Mumbai, who carried out the study, said the absorptive properties of banana fibre were known. The problem was that it absorbed both oil and water, reducing effectiveness.
Led by Mangesh D. Teli, professor of fibre and textile processing at the ICT, the researchers developed a means to treat banana fibres chemically so that they repel water while absorbing oil, a fossil fuel.
Their experiments showed that when banana fibres were 'acetylated' with acetic anhydride, their oil absorption capacity improved dramatically. The acetylation process was catalysed using N-Bromosuccinimide.
"Banana fibre’s water absorbing property is because of the hydroxyl groups in the chemical structure of cellulose. When treated with acetic anhydride, the hydroxyl groups get converted into acetates, which do not attract water," Teli told SciDev.Net
The authors claimed that acetylated banana fibre being biodegradable it will have no adverse environmental impact.
Bhaskar Rao, a natural fibre scientist at Indian Institute of Chemical Technology, Hyderabad, told SciDev.net that chemical treatment not only improved the oil absorption capacity of banana fibre but also increased its durability.
Rao added, however, that banana fibres may not be effective in dealing with oil spills that contain certain chemical pollutants. "Banana fibres will not be able to withstand the corrosive effect of some chemicals," Rao explained.
Prashant Kumar Bhattacharya, professor of chemical engineering at the Indian Institute of Technology, Kanpur, told SciDev.net that the fact that there was no organised collection of banana fibre could prove to be a deterrent in its use.
At present, organic chemical compounds like polypropylene and polyurethane form the bulk of sorbents or large sponges used in removing oil spills. However, such synthetic materials are non-biodegradable and pose problems of safe disposal.
On the other hand, oil soaked up by sorbents made of acetylated banana fibre can be recovered for use, the scientists said.