Method for oxidatively degrading chlorophenol substances by using EDTA (ethylene diamine tetraacetic acid)-reinforced bimetal aluminum-iron system

Abstract

The invention relates to a method for oxidatively degrading chlorophenol substances by using an EDTA (ethylene diamine tetraacetic acid)-reinforced bimetal aluminum-iron system. Machined metal iron and metal aluminum used as raw materials are filled in a reactor. Before treatment, a certain amount of EDTA is previously added into the reactor, and aeration and stirring are simultaneously carried out after starting introducing water. In the water, the metal aluminum can easily generate hydrogen peroxide after aeration, the EDTA after aeration can promote the metal iron to activate molecular oxygen to generate oxydol and can eliminate the passivation layer on the iron surface to reinforce the leaching of ferrous ions, the ferrous ions immediately produce Fenton advanced oxidation reaction immediately after contacting the hydrogen peroxide, and the generated.OH is subjected to advanced oxidation reaction. Meanwhile, the generated iron and aluminum hydroxides have the capacity for adsorbing and removing pollutants, and thus, are beneficial to further enhancing the quality of effluent water. The invention has the advantages of low operating cost and simplified technical process, implements quick decomposition of the EDTA, and can not bring about combined pollution of the EDTA. The treatment cost is low. The FeO used by the technique is machining waste of metal workpieces, the AlO is the most abundant metal element on the earth crust, and both the FeO and AlO are cheap and accessible and can be used for a long time.

Description

technical field [0001] The invention belongs to the application field of water treatment technology, and in particular relates to a method for oxidatively degrading chlorophenols by EDTA-enhanced bimetallic aluminum-iron system. Background technique [0002] Chlorophenols are a class of widely used wood preservatives, fungicides and herbicides. They have high toxicity and strong stability. The concentration threshold of toxic effects on humans is 40ppm, and they have toxic effects on fish The threshold value is only 1ppm. Therefore, the pollution of this kind of substances to the water environment has been widely concerned by countries all over the world. The US EPA has listed them as Priority Pollutants, and my country has also included them in the Blacklist of Key Pollutants. Research on new methods to efficiently remove chlorophenol pollutants in water has become a hot spot in the field of water treatment. [0003] At present, there are many methods for treating chlorop...

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Problems solved by technology

However, the reaction of zero-valent iron under aerobic conditions is accompanied by two processes that are unfavorable to the reaction: (1) The generation of hydroxide ions leads to an increase in the pH of the solution, which reduces the oxidation ability of the system, because Fe 0 / O 2 Interface H 2 o 2 The in situ formation and subsequent Fenton reaction are only effective at acidic pH (pH<3); (2) The precipitation of iron hydroxides accumulates at the reaction sites on the zero-valent iron surface, resulting in the passivation of the zero-valent iron surface and the reactivity the gradual loss of

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