A method for recovering chromium-containing wastewater using magnetic nanoparticles

Abstract

The present invention provides a method for recycling chromium-containing wastewater using magnetic nanoparticles. The magnetic Fe3O4 nanoparticles synthesized by a special process are used to directly extract chromium from the chromium-containing wastewater by combining magnetic Fe3O4 nanoparticles and chromium hydroxide colloidal particles to form nanoclusters and magnetic separation operations, thereby achieving complete removal of chromium from the chromium-containing wastewater, converting the chromium-containing wastewater into chromium-free wastewater, and subsequent chemical flocculation precipitation without chromium-containing hazardous waste discharge. Furthermore, the present invention uses an oxidant to oxidize the chromium hydroxide in the magnetic Fe3O4 nanoparticle-chromium hydroxide colloidal nanocluster combination into hexavalent chromate that is soluble in water, and through magnetic separation or solid-liquid separation operations, the magnetic nanoparticles are recycled and reused and the chromium resources are recycled and reused.