Wastewater treatment filtering material, and preparation method and use thereof

Abstract

The invention relates to a wastewater treatment filtering material, and a preparation method and a use thereof. The filtering material is formed by a porous ceramic matrix having an amount of porosity of 35-85% and nanometer zerovalent iron particles in-situ generated in the porous ceramic matrix, the micropore size of the porous ceramic matrix is 2-10mum, a fuzzy amorphous silicon-iron-carbon structure is formed in the micropore and can form an adsorbing film after absorbing water, and the material of the porous ceramic matrix is composed of 55-65 parts by weight of diatomite, 12-15 parts by weight of calcium-based bentonite, 7-12 parts by weight of carbon powder, 2-3 parts by weight of starch, and 4-6 parts by weight of kaolin. The filtering material obtained in the invention forms a nose-like porous fluffy filtering structure in the microstructure and generates the adsorbing film, so the absorbing efficiency is greatly improved, and the filtering material can be adapted to the chemical environment change of water. The shedding or heavy metal precipitation of the used filtering material does not appear, and the use safety of the filtering material is good.

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 ...

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

Images