Fish scales nobody wanted can pull a powerful antibiotic out of water

Antibiotics do not disappear when we are done with them. Ciprofloxacin, a widely used one, slips through ordinary sewage treatment and turns up in rivers, where even small amounts can help bacteria learn to resist medicines. In Paraná, Brazil, researchers have turned a fish-farm leftover into a possible answer: they took Nile tilapia scales donated by a local cooperative, COPISCES in Toledo, and made them into a charcoal-like material that grabs the drug out of water. Writing in Environmental Science and Pollution Research, the team reports that in lab tests each gram of the material held up to about 79 milligrams of ciprofloxacin. By testing the scales' two natural parts separately — the soft collagen part, which becomes the charcoal, and the hard mineral part — they showed the charcoal does most of the work, holding about twice as much of the drug as the mineral part. It is early days, honestly stated: the tests used beakers of made-up water, far stronger than any river, and nobody has yet shown the material can be cleaned and reused. But the idea is simple and appealing — a waste product the fish industry throws away, doing quiet work against drug pollution.

SDG 6 · Clean water and sanitation — Mechanism: tech innovation