According to Scientists at the University of Toledo, rice husks can remove microcystin toxins from water. A development that could have far-reaching implications for communities along the Great Lakes and across the developing world. The researchers published the study recently in the journal Science of the Total Environment.
Rice husks are inexpensive and abundant agricultural byproducts that have been investigated as a water purification solution in the past. The result of this study is the first time, however, that researchers showed how they remove microcystin, the toxin released by harmful algal blooms.
The chair of the Chemistry and Biochemistry Department and Distinguished University Professor, Dr. Jon Kirchoff said that delivering safe water is crucial and finding an economically viable solution to provide safe water to people all over the world is going to be indeed essential. The ability of this simple material to be powerful enough to address this issue is impressive.
Kirchoff and Dr. Dragan Isailovic, associate professor of chemistry in the College of Natural Sciences and Mathematics led the study that used organic rice husks that were treated with hydrochloric acid and heated to 250 degrees Celsius. Then, they dispersed the rice husks in a series of water samples collected from Lake Erie during the 2017 harmful algal bloom to measure how much of the toxin they could absorb.
In their findings, the rice husks removed more than 95 percent of microcystin MC-LR, the most common type found in Lake Erie, in concentrations of up to 596 parts-per-billion (ppb). Even in concentrations approaching 3,000 ppb, they removed more than 70 percent of the MC-LR. Also, they removed other types of MCs.
Isailovic explained that they looked at the removal of microcystins from real environmental samples and the material has performed quite well. They are talking about extremely high concentrations of microcystins originating from cyanobacterial cells.
Heating microcystin-laden rice husks to 560 degrees Celsius destroys the toxins and produces silica particles which can be used in other applications.
The team is hopeful that they could scale their findings beyond the lab to develop a more environmentally friendly method for treating water that has been contaminated by harmful algal blooms or cheap but effective filtration systems for the developing world.
Isailovic concluded that they could potentially use this readily material to purify water before it even gets into Lake Erie. There are engineering solutions that need to be done, but one of their dreams is to apply what they develop in their labs to provide safe drinking water.
