Cactus “Flesh” Cleans Up Toxic Water – Science Nation
♫MUSIC♫ MILES O’BRIEN: The prickly pear cactus salad.
It’s a delicacy in Mexico. But it seems these cacti have uses beyond the culinary, cleaning up oil spills and purifying water. NORMA ALCANTAR: You can see how it’s really easy to grow.
MILES O’BRIEN: With support from the National Science Foundation, University of South Florida Chemical Engineer Norma Alcantar is using the gooey flesh of the cactus, called mucilage, to clean up polluted water.
Her interest in green chemistry came from her grandmother, who told her of using cacti to clean river water in rural Mexico as a young woman.
NORMA ALCANTAR: They will take the cactus plant, but they will cut it, they will boil it, and they will use the water from that preparation to clean the water. MILES O’BRIEN: When Alcantar tested that process in her lab, she was amazed at the results. NORMA ALCANTAR: I couldn’t believe it. I was like, “Are you serious, it really works?” because I thought I will see an effect, but I didn’t think I will see an effect so dramatic.
MILES O’BRIEN: These biobeads are made of mucilage.
NORMA ALCANTAR: This is a controlled, initial concentration of the metal blue dye versus the one that has been in contact with the beads. MILES O’BRIEN: After an oil spill, cactus goo could be an alternative to chemical dispersants, like those used in the Deep Water Horizon cleanup.
NORMA ALCANTAR: The same action can be done with a very low concentration, and makes it very sustainable and fairly inexpensive.
MILES O’BRIEN: Alcantar did water quality tests in Haitian refugee camps after the 2010 earthquake, finding high levels of heavy metals and bacteria in the drinking water. While there, she kept an eye out for cacti, and they were everywhere. NORMA ALCANTAR: This is in a gas station. MILES O’BRIEN: Tests back at her lab confirm that mucilage could successfully clean the polluted water from Haiti, and that’s significant.
In the future, cacti could be harvested locally to decontaminate drinking water quickly, after disaster strikes. Using a natural product to clean water, it’s a sharp idea. After all, there’s no reason to get stuck on the old way of doing things.
For Science Nation, I’m Miles O’Brien.