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Microbeads are tiny sphere of plastic, less than 0.5mm in size, that are added to thousands of cosmetics products to give a smooth texture. They are too small to be filtered out by sewage treatment systems and many trillions of the microscopic beads ultimately end up in rivers and oceans, where they can be ingested by fish, birds, and other marine life. Although projects are being developed to scoop up larger pieces of ocean trash, the microbeads are too small to remove. After learning that a single shower can release as many as 100,000 microbeads into the ocean, the government of the United Kingdom has called for a total ban on the beads. Now, researchers at the University of Bath have developed a biodegradable alternative to plastic microbeads made from cellulose, a natural plant fiber. The cellulose is broken down into harmless sugars by organisms used in sewage treatment, and the beads can be manufactured in a continuous process – making them cost effective to produce.

The team at the university’s Centre for Sustainable Chemical Technologies, which developed the cellulose beads, worked with a multi-disciplinary approach from the start – integrating process design and chemistry. The beads are made by forcing a solution of cellulose through tiny holes in a tubular membrane, creating spherical droplets which are then collected. The physical properties of the beads can also be altered by changing the structure of the cellulose, for example, to make the beads harder or softer, or to impregnate them with chemicals such as slow-release fertilisers for use in agriculture. The researchers anticipate they could use cellulose from a range of “waste” sources, including from the paper making industry as a renewable source of raw material.

This project demonstrates ways in which multi-disciplinary teams of scientists and engineers can work together with industry to solve environmental problems in a cost-effective way. In the past, we have seen biodegradable cigarette butts and even biodegradable drones, what other types of industry might benefit from this approach?