A team of researchers from China’s Hunan University has developed a floating solution to help destroy harmful algal blooms (HABs) — which produce toxins that can cause illnesses in both humans and animals — in bodies of water.

The new environmentally safe solution for killing toxin-producing algae and cyanobacteria involves a floating sponge coated in a charcoal-like substance and paired with an oxidizing agent.

Graphical abstract. Source: ACS ES&T Water (2023). DOI: 10.1021/acsestwater.3c00202

To create the solution, the team combined a porous sponge composed of melamine with a powdered biochar derived from shrimp shells. Between the sponge and the biochar, the team added a thin layer of polyvinyl alcohol and linked the layers together at 572°. With the addition of a persulfate-based oxidizing agent, the floating sponge reportedly destroyed the membranes of roughly 90% of the M. aeruginosa cells present in lab samples within five hours. The researchers noted that once the membranes split, the cells expelled their internal contents, which then immediately degraded into smaller components.

Additionally, the researchers determined that the coated sponge destroyed more than 85% of algal cells present in real-world lake and river water samples.