Victoria University researchers helping to address nitrate pollution

Victoria University of Wellington PhD student Putri Fraser, alongside researchers from the School of Chemical and Physical Sciences, have combined iron and natural silicates to develop a new method of removing nitrate pollution from waterways. Nitrate pollution is a serious issue, deteriorating river habitats and decimating aquatic life.

“Previous research shows that nano-sized iron can remove pollutants from soil and waterways, but it’s not a perfect solution,” Putri says. “The iron is magnetic, so these nano-sized particles can clump up, reducing their reactivity and also making them difficult to work with. This clumping can also occur if they are ingested by fish, potentially harming wildlife.”

Putri tested several different products in a quest to find nano-sized iron that would be less likely to clump but retain its reactivity towards pollutants. A microsilicate product Putri first encountered at Callaghan Innovation in 2012 offered a possible solution.

A by-product of thermal power generation, this microsilicate can be coated with nano-sized iron, which increases the size of the nano-iron particles whilst retaining their reactivity. The silicate-coated nano-particles can be distributed more easily in the soil, and as it does not clump there is less cause for concern for negative interactions with fish.

Putri’s next move is to see whether this method can help with other pollutants.

“Along with a research team at the School of Chemical and Physical Sciences, I’m going to try different metals and coatings to see if there is a more effective combination, and also to see it’s possible to remove other pollutants from the soil using this method,” Putri says.