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Second life for phosphorus – Audio

Second life for phosphorus - Audio

Phil Barak, Professor
Department of Soil Science
UW-Madison College of Agricultural and Life Sciences
(608) 890-0689

 Second life for phosphorus

2:59 – Total Time
0:39 – What is phosphorus
0:28 – Mess in waste water treatment plants
1:01 – Phosphorus recovery potential
1:15 – Phosphorus extracted with process
2:05 – Pilot plant coming on line
2:50 – Lead out


Sevie Kenyon: A second life for phosphorus, we’re visiting today with Phil Barak Department of Soil Science University of Wisconsin-Madison in the College of Agricultural and Life Science, and I’m Sevie Kenyon.

Phil, what is phosphorus?

Phil Barak: Phosphorus is one of those elements that absolutely essential for plant growth, farmers use some of it as fertilizers all across the country and all across the world. Plants can’t grow without it.

Sevie Kenyon: And Phil you’ve encountered a situation with phosphorus, can you describe that for us?

Phil Barak: I found, while I was doing some research at a waste water treatment plant, I found that there were just mammoth streams of phosphorus and nitrogen coming into the waste water treatment plant and that they were really working hard to get this stuff gone. Their problem was that all of this stuff was coming off farm onto the tables, into the sewers, into their waste water treatment plant and it was their business to get rid of it. And it was no end to trouble for them to do that. It would stick in their pipes, go out in their bio-solids, none of it very good.

Sevie Kenyon: Phil what did you discover here that could change that?

Phil Barak: Well, it was a really amazing thing for me to realize that if we were able to remove some phosphorus from the bio-solid, we would make those bio-solids just that much more valuable for agriculture.

Sevie Kenyon: And Phil what is your process do?

Phil Barak: At a very particular and critical part of the waste water treatment plant, at a point where the phosphorus levels are really, really high, we apply a single chemical and we can precipitate out about 80-90 percent of the phosphorus as a calcium phosphate mineral. It rains down out of that water just like snowflakes and it collects at the bottom of the tub, and we can pick that up and collect it, and recycle it to agriculture. The beautiful part is that we’re able to take this phosphorus fertilizer out and put it wherever it’s needed and whenever it’s needed. So if we are sending it out of the water shed, that is just absolutely perfect. Instead of being sent out with great gobs of water and carbon and all this other bio-solid stuff, we are now sending it out as a form that is almost 35-40 percent phosphorous.

Sevie Kenyon: Phil, tell us a little bit about the future and what you are going to do with this process.

Phil Barak: Well right now we are planning to install our very first pilot plant. It will be profitable from two different directions. Number 1, it will collect a phosphorus mineral that can be recycled into agriculture and it has a value no less than the phosphorus fertilizers today. Because instead of mining virgin materials for phosphorus, here we are recovering phosphorus that has already seen life once in the city and putting it back on the farm where it belongs. The other part of it is, is that the waste water treatment plants have a great deal of difficulty with that phosphorus forming precipitates inside their plant, and so they have very high maintenance costs trying to deal with the phosphorus. And the third part of it is, of course, if we remove it from the bio-solids, that means the bio-solids are improved and can be spread more extensively and closer to the plants.

Sevie Kenyon: We’ve been visiting with Phil Barak Department of Soil Science University of Wisconsin-Madison in the College of Agricultural and Life Science, and I’m Sevie Kenyon.