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NSERC Presents 2 Minutes with Donald S. Mavinic
Civil Engineering, The University of British Columbia


Video Name

2 Minutes with Donald S. Mavinic


NSERC Communications



Release Date

September 26, 2011


As a component of DNA and a key ingredient of fertilizer, phosphorus is essential for all living things. Dr. Donald S. Mavinic and his co-researchers at The University of British Columbia's Department of Civil Engineering have developed technology that recovers 85 percent of phosphates from wastewater streams and converts it into an innovative new fertilizer.

2 Minutes with Donald S. Mavinic

Donald S. Mavinic

Here's the issue we have. On my right here you see the problem. The fertilizer forms in the sewage treatment pipes and this is impossible to remove. It's a big maintenance headache for the wastewater treatment plant people, the personnel. And it cannot be removed. Ironically, this is a nice fertilizer.

The way this works is the treated effluent from the sewage treatment plants there has to be a biological sewage treatment plant, no chemicals allowed and the bio solids remove the carbon and a lot of the phosphorus and a lot of the nitrogen and those bio solids have to be further processed. When the biosolids are processed or digested, as we call, the liquid component reclaims a lot of the nutrients, especially phosphorus. Phosphorus has no gaseous phase so it cannot be destroyed. So everything that has been removed in the form of phosphorus essentially ends up in the biosolids and then when the biosolids are further treated or digested, that liquid actually has the material in it. So when it goes, when that liquid which is now a pollutant again has to be recycled to the head of the treatment plant. As soon as magnesium comes into play with it in the right molar ratios, this crystal lattice starts to form in the pipes and pumps, plugs it up, you can see the change in the diameter and then the municipalities, the waste treatment plant operators have no choice but to physically remove the pipe and replace it with clean pipe and this happens on an annual basis. So that becomes the problem with the fertilizer—so it's got magnesium, ammonium phosphate but it's not in a form that we can use. The technology we develop, it brings it into this form—which are the pellets—and this is now very valuable as a commercial fertilizer, and it's called Crystal Green. So there's a problem, here's a solution.

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