Sulfide nanometer zero-valent iron particle as well as preparation method and application thereof

Abstract

The invention discloses a sulfide nanometer zero-valent iron particle as well as a preparation method and application thereof. The preparation method of the sulfide nanometer zero-valent iron particlecomprises the following steps: 1) reacting ferrite and NaBH4, and preparing nanometer zero-valent iron particles; and 2) coating the nanometer zero-valent iron particles with elemental sulfur powder,and preparing elemental sulfur coated nanometer zero-valent iron particles. The nanometer zero-valent iron particles are subjected to coating modification by taking the elemental sulfur powder as a sulfur source, the preparation method is mild in reaction conditions, simple in operation and low in production cost, and large-scale production is conveniently performed. Moreover, the prepared sulfide nanometer zero-valent iron particle has high selectivity on targeted pollutants and high reductive transformation efficiency, and can be applied to repair treatment of contaminated underground wateror soil on a large scale.

Description

technical field [0001] The invention relates to a sulfurized nanometer zero-valent iron particle and a preparation method and application thereof. Background technique [0002] Nano zero-valent iron particles are widely used in the treatment of polluted groundwater and soil, which has the following advantages: 1) Strong reducing ability; 2) After being used for pollutant treatment, it will transform itself into iron oxide, which has little impact on the environment ; 3) The particle size is small, the particle size is uniform, and the specific surface area is large; 4) It is easy to use, and it can be injected into the polluted groundwater or soil through the injection well to carry out in-situ repair, and it can contact the fine aquifer, and the pollution of the polluted water body The purification is more thorough. [0003] However, there are still the following defects and deficiencies in the practical application of nano-zero-valent iron particles: 1) Under the influenc...

AI Technical Summary

Problems solved by technology

[0003] However, there are still the following defects and deficiencies in the practical application of nano-zero-valent iron particles: 1) Under the influence of van der Waals force, magnetic force and other surface forces, nano-zero-valent iron particles are easy to aggregate into particles with larger particle sizes, and the reaction The activity is greatly reduced; 2) In the actual pollution remediation process, the reactivity of nano-zero-valent iron particles is high, and electrons can be arbitrarily transferred to H 2 O, dissolved oxygen (DO) and nitrate (NO 3 - ) and other electron acceptors will consume a large amount of reducing power, reducing its selectivity to target pollutants and reduction conversion efficiency

[0008] At present, the vulcanization reagents used in the synthesis of vulcanized nano-zero-valent iron particles include Na 2 S 2 o 4 and Na 2 S, but Na 2 S 2 o 4 It has certain oxidative properties, which will cause a large amount of Fe(0) to be converted into FeS, which greatly consumes the initial reducing power provided by Fe(0), while Na 2 S is easy to deliquesce in the air and absorb CO 2 and deteriorate, and will continue to release toxic and harmful H 2 S gas, so the large-scale production and application of sulfide-type nano zero-valent iron particles are greatly restricted

Images