Silicification modified zero-valent iron and preparation method and application thereof

Abstract

The invention provides silicification modified zero-valent iron. The surface layer of the silicification modified zero-valent iron is a silicate-substituted silicon-containing oxide layer, and the silicification modified zero-valent iron is obtained through the following method that soluble silicate and micron iron powder serve as raw materials and are mixed in proportion, ball milling is conducted in the inert gas atmosphere, and the silicification modified zero-valent iron is obtained. The silicon-containing precursor and the micron zero-valent iron are mixed in proportion and then modifiedby adopting a mechanochemical way, and the obtained silicification modified zero-valent iron can be used as a sewage remediation agent, an underground water in-situ injection material and a permeablereactive barrier filling medium and is suitable for remediation and treatment of heavy metal polluted environments. Green silicate is used as a silicon source to perform surface silicification modification on micron zero-valent iron, operation is simple, cost is low, large-scale production is facilitated, and the prepared silicified zero-valent iron is good in dispersity, high in reduction activity and high in recycling performance and can be used for treatment of water and soil polluted by various heavy metals.

Description

technical field [0001] The invention belongs to the technical field of preparation of environmental materials and restoration of polluted water bodies, and in particular relates to siliconized modified zero-valent iron. [0002] The present invention also relates to the preparation method of the silicified modified zero-valent iron. [0003] The present invention also relates to the application of the silicified modified zero-valent iron in repairing water bodies polluted by various heavy metals. [0004] technical background [0005] With the rapid development of industry and agriculture, the problem of heavy metal pollution in global water is becoming more and more serious. The heavy metal ions entering the environment are difficult to be biodegraded, but they are easily enriched by biotransformation. Long-term exposure or use of water polluted by such heavy metals will bring serious danger to surrounding residents and the ecological environment. For example, long-term u...

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Problems solved by technology

However, zero-valent iron often has the defects of easy passivation, easy agglomeration, and easy loss of activity during use. decreased activity

In response to this defect, the predecessors used measures such as pickling, ultrasonication, and magnetization to remove or alleviate the inhibition effect caused by the oxide layer on the surface of zero-valent iron. However, the formation of this oxide layer in aqueous solution is unavoidable.

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