Arsenic removal filter material, preparation method of arsenic removal filter material and application of arsenic removal filter material in drinking water purification

Abstract

The invention relates to an arsenic removal filter material, a preparation method of the arsenic removal filter material, and an application of the arsenic removal filter material in drinking water purification. The filter material consists of a porous ceramic substrate, and nano zero-valent iron particles generated in the porous ceramic substrate in situ, wherein the micropore size of the porous ceramic substrate is 2-10 micrometers; fleece-like undefined silicon-iron-carbon structures are formed in micropores, and can form an adsorption film after absorbing water; and the porous ceramic substrate comprises the following materials in parts by weight: 50-55 parts of kieselguhr, 6-8 parts of bentonite, 3-4 parts of starch, 3-5 parts of kaoline, 1-2 parts of liquid wax, 1-3 parts of iron powder and 13-15 parts of powdered carbon. According to the filter material, a porous downy filter structure similar to a nose is formed in a microstructure, and the adsorption film is generated, the adsorption efficiency is improved greatly, and the filter material adapts to the hydrochemistry environment change. The used filter material does not fall or precipitate heavy metal, and is good in use safety.

Description

technical field [0001] The invention belongs to the field of filter material preparation, and in particular relates to a filter material capable of absorbing and fixing arsenic and heavy metals, its preparation method and application. The filter material can effectively remove trivalent arsenic and pentavalent arsenic contained in fluid such as water. Background technique [0002] Arsenic is one of the highly toxic elements, and it is also the main inorganic toxin removed in the drinking water standards of various countries. It exists mostly in trivalent and pentavalent states in natural water bodies. However, as a metal element, it does not exist in the state of common cations, but mainly exists in the form of arsenite and arsenate. Even modern technologies such as reverse osmosis membrane (RO) have a removal rate of only about 50% for trivalent arsenic, which cannot meet the filtration requirements for arsenic. In addition, the filter material must take into account the ...

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Problems solved by technology

However, the single application of zero-valent iron brings the following problems: 1. The corrosion reaction can only occur in an environment with a pH less than 7. Adjusting and controlling the pH is the application limit of drinking water filtration; 2. There must be a certain amount of dissolved oxygen in the water (greater than 2 mg / L) to continue the reaction; 3. Harmful sludge is formed during the reaction process, which cannot fix heavy metals, and further harmless treatment is required; 4. A large amount of excess ferric or ferrous ions are produced during use, making the Water is red or orange and must be treated further

But the way of coating still has some problems, as the coating prepared by activated carbon mixing method is easy to come off when pH changes or water quality changes, and this can cause acute poisoning in drinking water; The problem of surface oxidation, which reduces its adsorption capacity

[0005] Chinese invention patent ZL200680052402.X discloses a method and composition for removing arsenic and heavy metals from water, in which the method of using kaolin ceramic particles for zero-valent iron coating can effectively remove arsenic and heavy metals and achieve heavy metal fixation on the ceramic surface , but this method can only use the ceramic surface structure, and the adsorption efficiency needs to be further improved

[0006] In summary, the main disadvantages of the prior art for the removal of arsenic are: 1. The traditional ceramic oxidation and calcination can only provide a porous structure to filter bacteria and macromolecules for physical filtration; 2. The application of zero-valent iron powder produces more iron Ions and hazardous waste; 3. The activated carbon iron powder coating has the problem of shedding; 4. The surface coating of ceramic particles can only use the surface structure

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