Method for preparing emulsified nanometer grade zero valent iron and nanometer grade bimetal and use thereof

Abstract

The invention discloses the method for preparation of emulsified nanometer zero valence iron and nanometer bimetallic. The method comprises the following steps: 1 adding the NaBH4 solution into the mixture solution of FeSO4.7H2O and stabilizing agent which is amylogen, getting the emulsified nanometer zero valence iron, the density of amylogen being 0.2-2%, the mole ratio of NaBH4 and FeSO4.7H2O solution being 2:1; 2 mixing emulsified nanometer zero valence iron and K2PdCl6 solution, carrying out reaction, entering nitrogen, when the color of solution changed from bistre to pea green, getting the nanometer bimetallic, the proportion by weight of Pd and Fe being 5-10:10000. The emulsified nanometer zero valence iron and nanometer bimetallic are used to restore the pollution water containing chlorine, nitrate anion and heavy metal. The method is simple, the specific surface area of emulsified bimetallic particle is large, the dispersity is good, and the chemical reactivity is high.

Description

technical field [0001] The invention relates to a preparation method and application of emulsified nano-scale zero-valent iron and nano-scale bimetal. Background technique [0002] Various pollutants discharged in the process of production and life enter the environment through various channels, seriously polluting the atmosphere, soil, groundwater and surface water systems, and seriously threatening the healthy life of human beings. Chlorine-containing organic compounds, nitrates, and heavy metals are common priority pollutants in groundwater, and these pollutants are usually mixed in polluted water or soil. [0003] A considerable portion of chlorinated organic compounds are listed as environmental priority pollutants, especially persistent organic pollutants, such as DDT, HHH, PCBs, polychlorinated phenols, vinyl chloride (VC), etc. Biological metabolism, photodegradation, chemical decomposition, etc. have strong resistance. Once discharged into the environment, it is di...

AI Technical Summary

Problems solved by technology

[0006] Although metallic iron can effectively dechlorinate and denitrify chlorinated organics and nitrates, they all face the following challenges: (1) metallic iron has low reactivity to certain chlorides (such as chlorinated hydrocarbons, PCBs, etc.), The reaction speed is relatively slow, resulting in incomplete dechlorination and the formation of other chlorine-containing by-products

In the nitrate denitrification reaction, pure Fe is used as the reducing agent, and the reaction process needs to adjust the pH value to weak acidity (the pH will gradually increase to neutral during the reaction process). If the experimental conditions are not properly controlled, or the reaction time is not enough More ammonia nitrogen and more toxic nitrite; (2) As the reaction progresses, metal hydroxide or carbonate passivation layer is gradually formed on the surface of metal iron, which reduces the reactivity of iron