Thanks @chand. That was the post I was looking for:). I think...

Thanks @chand. That was the post I was looking for. I think that's a Bullseye.

"The process uses permeable bags which, as water flows through, nanoparticles ensure rapid
uptake of phosphorus. On removing the bag from the water, a process enables the captured
phosphorous to be removed, and can be on-sold as a slow release fertiliser. In the treatment,
there is no leaching or loss of captured phosphorus, even under extreme environmental
conditions."