Faster removal of cigarette filters from the environment
Cigarette filters that have been inappropriately discarded are a major environmental problem, making up a large proportion of litter, as the filters themselves can take years to degrade. In a bid to tackle this, researchers in the US have developed a cigarette filter with accelerated degradation.Raymond Robertson from the acetate business of Celanese Corporation, Narrows, Virginia, has been working with colleagues to develop a filter that contains a controlled-release organic acid to catalyse the hydrolysis of the filter material – cellulose acetate polymer. ‘Our work focuses on expediting the filter degradation back to cellulose and acetic acid using edible materials, such as citric acid and ascorbic acid (vitamin C), to help promote the filter degradation rate,’ he says. ‘Increasing the degradation rate decreases the filter persistence in the environment.’The weak organic acid is encapsulated in the filter paper to protect it from premature degradation and to prevent a decrease in the product’s shelf life. Once the cigarette is used and discarded, environmental water (such as rainwater) breaches the protective layer. This releases the acid, which migrates into the filter, lowering the pH and triggering hydrolysis.