摘要 |
Nanoparticle-treated particle packs, such as sand beds, may effectively filter and purify liquids such as waste water. Proppant beds treated with nanoparticles may fixate or reduce fines migration therethrough. When tiny contaminant particles or fines in these fluids flow through the nanoparticle-treated bed or pack, the nanoparticles will capture and hold the tiny contaminant or fines particles within the pack due to the nanoparticles' surface forces, including, but not necessarily limited to van der Waals and electrostatic forces. Nanoparticle-treated beds or packs may be recharged by contacting the bed with an inorganic acid (but not hydrofluoric acid) or an organic acid, and optionally followed by subsequent treatment with hydrofluoric acid. This treating substantially removes the nanoparticles and the fine particulates that have been removed from a fluid (e.g. wastewater being treated, produced fluids in a formation, etc.). The particle pack may then be re-treated or recharged with nanoparticles.
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