Calcium polysulfide vulcanized zero-valent iron nano composite material as well as preparation method and application thereof

Abstract

The invention discloses a calcium polysulfide vulcanized zero-valent iron nano composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: uniformly mixing a calcium polysulfide solution with a sodium borohydride solution, dropwise adding the mixture into a ferrous sulfate heptahydrate solution, carrying out a stirring reaction, introducing inert gas into each solution before the reaction to remove dissolved oxygen in water, in the reaction process, stirring under the protection of inert gas, after the reaction is finished, collecting nanoparticles in a centrifugal mode, then carrying out cleaning and freeze drying so as to obtain the calcium polysulfide vulcanized zero-valent iron nano composite material, wherein the molar ratio of the sulfur element to the iron element is 1: 20-1: 2. The vulcanized zero-valent iron is prepared through calcium polysulfide modification, the stability and the reduction characteristic are remarkably improved, 100% removal can be rapidly achieved when the vulcanized zero-valent iron is used for removing high-concentration Cr (VI) in water, the vulcanized zero-valent iron can be repeatedly used, meanwhile, long-term storage and long-distance transportation are facilitated, the preparation process is simple, and the invention has wide industrial application prospects.

Description

technical field [0001] The invention belongs to the technical field of composite materials, and in particular relates to a calcium polysulfide sulfide zero-valent iron nanocomposite material and a preparation method and application thereof. Background technique [0002] Hexavalent chromium (Cr(VI)) is a toxic pollutant widely present in the environment. Due to the rapid development of industry, chromium and its compounds are widely used as important raw materials, including wood and paper processing, dye production and leather tanning. ) main source. [0003] The chemical reduction of Cr(VI) to Cr(III) is a feasible and effective technique to reduce the toxicity and stabilization of Cr(VI) in contaminated sites. Several reducing agents have been proposed for the remediation of Cr(VI)-contaminated soil and water bodies, including OC, sodium thiosulfate, zero-valent iron nanoparticles, iron filings, and Fe(II) iron. Nano zero-valent iron is an environmentally friendly reduc...

AI Technical Summary

Problems solved by technology

However, nano-zero-valent iron still has problems such as easy agglomeration, easy deactivation, and clogging of underground aqueous media, and the removal efficiency of Cr(VI) is low, especially for high-concentration Cr(VI).

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