A floating sponge could help remove harmful algal blooms

Swaths of electric green and bright orange-red HABs, or the less brilliantly colored cyanobacteriaMicrocystis aeruginosa, can produce toxins that can sicken humans and animals. Researchers have shown that acids and strong oxidizing agents damage and destroyM. aeruginosa细胞,但同时产生不必要的,有效的ially harmful products. More recently, Jiangfang Yu, Lin Tang and colleagues suggested that persulfate-based oxidants could control this species' algal blooms, but these compounds require catalysts, such as powdered biochar -- a charcoal-like substance made from carbon-containing waste -- to be effective. So, the team wanted to develop a floating material containing biochar that would boost the destruction of harmful algal cells without damaging the environment with byproducts.

研究人员开始运动ous sponge made of melamine and developed a powdered biochar from shrimp shells. They sandwiched a thin layer of polyvinyl alcohol between the sponge and the biochar, linking the layers together at 572 degrees Fahrenheit. In combination with a persulfate-based oxidizing agent, the floating sponge damaged the membranes of about 90% of theM. aeruginosacells in lab dishes within five hours. After the membranes split apart, the cells released their internal contents, which rapidly broke down into smaller components. In addition, the researchers applied the catalyst sponge and persulfate system to real-world lake and water samples, and found that it inactivated more than 85% of the algal cells. Based on the results, the team suggests that the new system could be a successful algal remediation technique in environments affected by blooms.

The authors acknowledge funding from the National Natural Science Foundation of China, the China Postdoctoral Science Foundation, the National Key Research and Development Program of China, the Hunan Natural Science Foundation of Hunan Province and the Changsha Municipal Natural Science Foundation.