Method for treating organic dyestuff in wastewater

Abstract

The invention discloses a method for treating organic dyestuff in wastewater. The method comprises the steps of: firstly, preparing nanometer zero-valent iron, then placing the nanometer zero-valent iron into a wastewater solution, electrolyzing the wastewater solution, and introducing oxygen at a cathode part so as to degrade the organic dyestuff in the wastewater solution. According to the method for treating the organic dyestuff in wastewater, a large amount of Fe<2+> is generated from the zero-valent iron through electrolysis under an electric action, H2O2 is generated at the cathode part, the generated Fe<2+> and H2O2 undergo Fenton reaction with the organic dyestuff in the wastewater to treat the wastewater, and the reacted Fe<2+> and H2O2 generate hydroxyl radicals and Fe<3+>, the nanometer zero-valent iron and the Fe<3+> further react to generate the Fe<2+>, and thus, the Fenton-like reaction between the Fe<3+> and the H2O2 is reduced, a system is kept contain sufficient Fe<2+> and have a stable pH value, and the generation of the hydroxyl radicals is facilitated, so that a better effect on degrading the organic dyestuff is achieved.

Description

technical field [0001] The invention relates to a method for treating organic dyes in waste water, in particular to a method for treating organic dyes in waste water with Fenton's reagent. Background technique [0002] With the advancement and development of science and technology, the number and types of chemicals are increasing, and many treated and untreated toxic organics flow into the water, and after dilution, they become trace or even ultra-trace pollutants, many of which are difficult to be absorbed by nature. It is degraded by various chemical reactions and biological reactions, causing environmental pollution and ecological damage, and seriously endangering human health. At present, the methods for treating wastewater containing organic dyes include chemical oxidation, adsorption, and photocatalytic oxidation. These methods are not ideal for the treatment of toxic and refractory organic dyes. [0003] The classic treatment method for organic dyes in wastewater is...

AI Technical Summary

Problems solved by technology

In recent years, in order to efficiently treat organic dye wastewater, many new electro-Fenton systems have emerged, which mainly focus on the reduction of oxygen to produce H 2 o 2 The preparation of cathode materials used, such as mercury pool, reticulated glassy carbon, activated carbon fiber, carbon felt, etc., these methods involve complex preparation and high cost

Iron filings have also been reported as an iron source in the Electro-Fenton system (CN102060355A). However, the surface of the iron filings is passivated and the specific surface area is small, so the initial iron filings cannot fully dissolve and release Fe. 2+ , with H at the cathode 2 o 2 The amount of hydroxyl radicals produced by the reaction is insufficient. Therefore, the efficiency of iron filings as an iron source in the Electro-Fenton system for wastewater treatment is still low, and the degradation effect of organic matter in wastewater is not ideal.

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