Toxic algal blooms have been happening more often in the rivers off Lake Okeechobee. One of the main causes is phosphorous runoff from wastewater and farmland. But a new filter may make algal blooms caused by wastewater a thing of the past.
The U.S. Geological Survey has designed a new filter system that removes phosphorus from wastewater. It uses a discarded coal mining byproduct called mine drainage ochre to do it.
Philip Sibrell, an engineer with USGS, said the system is simple from a mechanical standpoint.
"Say we have some water from a point source," he said. "We could run that water through the filter and remove the phosphorus without any additional treatment."
The filter removes phosphorus which is often the culprit for harmful algal blooms. Phosphorus is a natural and necessary element. It's in urine and fossils. And it's used in fertilizer and in agriculture.
Sibrell said other filters exist to remove phosphorus.
"[But] usually, the phosphorus is not recoverable from those materials," he said.
But with this new filter, the phosphorus can be extracted and reused for farming and other things.
Sibrell said it'll be a couple of years before the new filtration technology is used in wastewater treatment plants around the country. And even then, he said, it'll take a while to reverse the adverse effects of an overabundance of phosphorus in the environment. That means it'll be a few more years before we see this technology reduce the number of harmful algal blooms in Florida.
But, Sibrell said, it's a step in the right direction.