Crayfish shells, often treated as waste, are being repurposed as a functional material to capture microplastics in water, addressing pollution across oceans, rivers, soil, and air.

Researchers have secured more than 30 patents and report commercialization value exceeding 800 million yuan (over $118 million).

A Wuhan University team, led by Professor Deng Hongbing, uses the shells’ fibrous structure—with chitin forming the framework and proteins and calcium carbonate providing rigidity—to enable effective microplastic capture.

Tests across Wuhan University ponds, the Yangtze River, and the Bohai Sea show broad applicability and interest from companies designing water-purification filter cartridges.

Overall, the work demonstrates a pathway for turning biological waste into valuable water-purification materials and advancing circular economy goals.

Beyond crayfish shells, the team has developed a biodegradable sponge from squid pens and pollen grains that adsorbs nanoplastics with high efficiency and recoverable performance through repeated use.

After a specialized treatment, crayfish shells gain a positive charge that attracts negatively charged microplastics, boosting capture efficiency.

The shell-based material is reusable, as trapped plastics can be removed, aligning with sustainable turning-waste-into-value principles.