Filter core material of household filter and preparation method thereof

Abstract

The invention relates to a filter core material of a household filter and a preparation method thereof. The filter core material is composed of porous ceramic substrate and nano zero valence iron particles in-situ formed in the porous ceramic substrate, the sizes of the micro-pores are in the range of 2 to 10 micrometers, furthermore, villiform amorphous silicon-iron-carbon structures are formed in the micro-pores, and the villiform amorphous silicon-iron-carbon structures in the micro-pores can form an absorbing membrane after absorbing water. The porous ceramic substrate is composed of following components in parts by weight: 75 to 85 parts of diatomite, 8 to 10 parts of carbon powder, 1 to 3 parts of bentonite and 3 to 5 parts of kaolin. The filter core material has nasal-analog, porous and villiform filtering structures in micro-structure, the structures can form an absorbing membrane, so the absorption efficiency is largely improved, and the filter core material can adapt to the chemical environment change of water body. The filter core material is safe in use because no heavy metal will fall off or separate out from the used filter material.

Description

technical field [0001] The invention relates to a household filter core material capable of effectively removing trivalent arsenic and pentavalent arsenic in water and a preparation method thereof. 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 fixation problem after adsorption for the filtration of arsenic and extremely toxic heavy metals. [0003] Traditional porous ceramics and ceramic filter e...

AI Technical Summary

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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