▎ 摘　　要

NOVELTY - Treating chromium-contaminated soil involves preparing graphene oxide-loaded nano-iron nanoparticles by a liquid-phase reduction method, utilizing nanoparticles to pre-adsorb the chromium-contaminated soil, and pre-adsorbed solidification and compounding chromium-contaminated soil and geopolymer. Graphene oxide supported nano-iron nanoparticles are prepared. Pre-adsorption treatment is performed. Alkali stimulant is prepared followed by preparing a composite material by pre-adsorbing the graphene oxide-loaded nano-iron nanoparticles to chromium-contaminated soil, and mixing the sodium water glass alkali activator with water uniformly, adding geopolymer to obtain graphene oxide loaded with nano-iron/geopolymer composite material mixed slurry, installing mixed slurry in the mold and vibrating, coating petroleum jelly on the surface, and finally using polyethylene film encapsulation and curing at room temperature to obtain graphene oxide supported nano-iron/geopolymer composite material. USE - Method for treating chromium contaminated soil. ADVANTAGE - The method enables effectively reducing leaching toxicity of the chromium polluted soil, and reinforcing compressive property of the material. DETAILED DESCRIPTION - Treating chromium-contaminated soil involves preparing graphene oxide-loaded nano-iron nanoparticles by a liquid-phase reduction method, utilizing nanoparticles to pre-adsorb the chromium-contaminated soil, and pre-adsorbed solidification and compounding chromium-contaminated soil and geopolymer. Graphene oxide supported nano-iron nanoparticles are prepared, certain amount of graphene oxide is measured, distilled water is added to dilute, and ultrasonically shake to make a dispersion of graphene oxide, added it to the dispersion of graphene oxide sequentially ferrous sulfate aqueous solution, anhydrous ethanol and distilled water, and nitrogen gas while stirring, after stirring for a certain period of time, add potassium borohydride solution dropwise to the dispersion after titration is completed, stir for 40-60 minutes, washed and filtered with anhydrous ethanol for three times, vacuum dried at 30-40 degrees C to obtain graphene oxide loaded nano-iron nanoparticles. Pre-adsorption treatment is performed by weighing a certain amount of graphene oxide loaded nano-iron nanoparticles into distilled water, ultrasonically dispersing for 30 minutes to prepare a dispersion, and adding chromium contaminated soil to the dispersion, and performing the dispersion under ultrasonic vibration and dispersion conditions, pre-adsorbing chromium-contaminated soil, where the water-cement ratio of the dispersion system of the chromium-contaminated soil is 0.5-1.5 after the pre-adsorption treatment is completed, vacuum drying at 30-40 degrees C to obtain graphene oxide-loaded nano-iron nanoparticles pre-adsorbed chromium contaminated soil. Alkali stimulant is prepared by grinding sodium silicate nonahydrate, adding distilled water to the ground sodium silicate nonahydrate, and ultrasound at 40 degrees C to completely dissolve to obtain sodium water glass alkali stimulant, which is composed of sodium nonahydrate and water at mass ratio of 1-4:1 followed by preparing a composite material by pre-adsorbing the graphene oxide-loaded nano-iron nanoparticles to chromium-contaminated soil, and mixing the sodium water glass alkali activator with water uniformly, adding geopolymer and mixing uniformly to obtain graphene oxide loaded with nano-iron/geopolymer composite material mixed slurry, installing mixed slurry in the mold and vibrating, curing for 5-30 hours, after removing the mold, coating petroleum jelly on the surface, and finally using polyethylene film encapsulation and curing at room temperature to obtain graphene oxide supported nano-iron/geopolymer composite material, where the geopolymer is fly ash and blast furnace slag at mass ratio of 1:4, and the liquid-solid ratio of the mixed slurry is 0.3-0.4.