Method for improving zero-valent iron dechromisation catalytic reduction liveness in neutrality condition

Abstract

The invention relates to a method of raising zero-valent iron chromium removal catalytic reduction activity in neutral condition, characterized in that the electrolyte with 0.1 to 0.5 mol ferrous sulfate, 0.3 to 0.6 mol boric acid, 0.4 to 0.7 mol ammonium sulfate, 0.003 to 0.006 mol saccharin, 0.003 to 0.006 mol ascorbic acid, 0.002 to 0.004 mol sodium dodecyl sulfate per litre is deposited. Add the produced zero-valent iron into the solution with Cr (VI) in. Oxalic acid, citric acid, salicylic acid, tartaric acid or humic acid can also be added into the solution. The Ph of the solution is adjusted to 6.5 to 8.0 and the Cr (VI) content in the solution reduces remarkably. The method has the advantages of simple preparation technology, convenient operation and low cost. The produced zero-valent iron has a diameter less than 50 nm and is of uniform granularity and high catalytic activity. With 2.2 times chromium removal efficiency of ordinary methods, the method of raising zero-valent iron chromium removal catalytic reduction activity in neutral condition has a promising application prospect in remedying polluted soil and sewage.

Description

technical field [0001] The invention relates to a method for treating heavy metals in sewage, in particular to a method for removing chromium from water by catalytic reduction of zero-valent iron. Background technique [0002] Remediation of contaminated soil and groundwater with zero-valent iron is an emerging method in the world in recent years. It has high removal efficiency for heavy metals, low cost, simple follow-up treatment, cheap and easy-to-obtain raw materials, and is economically reasonable. It is a pollution with great potential. Restoration technology is expected to develop an in-situ water treatment device that is simple and practical, low in operating costs, and large in processing capacity. However, due to the existence of oxides on the surface of the zero-valent iron prepared by traditional chemical methods, the catalytic reduction activity is low under the condition of neutral pH of the solution. If zero-valent iron is prepared by electrodeposition, the g...

AI Technical Summary

Problems solved by technology

However, due to the existence of oxides on the surface of zero-valent iron prepared by traditional chemical methods, the catalytic reduction activity is low under the condition of neutral pH of the solution.

If zero-valent iron is prepared by electrodeposition, the generation of surface oxides can be prevented, and the activity of zero-valent iron can be improved to a certain extent, but it is still not ideal.

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