New research by Australia's CSIRO science agency finds that "Mineral-based by-products generated by mining or mineral processing offer a potentially cost-effective solution to wastewater treatment. CSIRO has undertaken the first comprehensive characterisation of a suite of by-products that have potential for use in purification of a range of wastewaters and for managed aquifer recharge. The productive use of these by-products reduces the environmental footprint of the mining and mineral processing industries." [right, a pile of neutralised used acid (NUA) from the heavy mineral processing industry prior to use in field experiments as a soil amendment. Credit, CSIRO]
The agency's project website says, "A wide range of by-products or other potentially beneficial mineral-based materials were assessed in laboratory column trials or field trials. The tested materials included neutralised used acid (NUA) from the heavy mineral processing industry, a steelmaking by-product, red mud and red sand from the alumina refining industry, activated carbon, calcined magnesia, attapulgite, zeolite, fly ash, laterite, groundwater treatment residues, carbonate minerals and a range of rocks common in south-west Western Australia."
There are large waste rock and tailings piles across Arizona and the West that might be suitable for testing this process.