A potential use for a waste product in the paper recycling process has been found by Argentine scientists.
Researchers from the Universidad Nacional de La Plata have found a way to extract short-chain celluloses from the paper recycling effluent, and turn it into a carboxymethylcellulose.
Usually, the effluent material is landfilled or used in energy from waste plants as a fuel, but the process discovered by the scientists means that the short-chain celluloses could be recycled into the carboxymethylcellulose product that is typically used as a thickening agent in products such as food, personal care products, detergents, paints, textiles and even in the paper industry.
Although the researches were unable to remove all of the impurities meaning it was a slightly different colour and has lower water absorbing properties, they believe further purification steps could be incorporated into a production process to make it suitable for other applications.
The process involves mixing samples of short-chain cellulose from the sludge with isopropanol and sodium hydroxide and stirring for one hour at room temperature.
Acetic acid is then added and the mixture is stirred for three hours at 55°C. The mixture is then cooled to 30°C and incubated for up to 21 hours before various separation and drying stages.