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Doing us a solid: Engineering team works to figure out effective ways to extract phosphorus from wastewater

You could say that CCEE Associate Professor Doug Call has a healthy obsession with wastewater. He gets “excited” about wastewater — his word, not ours — because of what it contains: water, chemical bonds containing energy, and a couple of essential nutrients for plants.

Much of Call’s work involves turning the microbes found in wastewater into electricity, which he describes as “very sci-fi” stuff that could help treatment plants reduce energy costs by producing their own energy.

His team also works to help treatment facilities be more efficient in removing phosphorus — one of those essential nutrients — from wastewater. Treatment facilities have been using biological methods — think sci-fi microbes again — to remove phosphorus from wastewater for years. The microbes do that by vacuuming up the phosphorus so that it can be more easily extracted.

CCEE Associate Professor Doug Call, left, demonstrates research materials to the Director of the White House Office of Science and Technology Policy Arati Prabhakar.

Removing the phosphorus has a couple of key benefits: The phosphorus can be used to reduce the reliance on mined phosphorus, a non-renewable resource, as an essential ingredient in fertilizer, and it limits the amount of phosphorus in water runoff that can lead to algae blooms that threaten marine life.

But Call says there are periods of instability when the microbes are not as successful at converting the phosphorus into a solid. His team’s challenge is to figure out what causes those periods — possibilities include changing weather patterns or periods of heavy rain or drought — and then search for a solution.

“Because at the heart of it is the microbial community,” he says. “You’ve got to have the right microbes doing the right things.”

This story first appeared in NC State Magazine.