Polyvinyl alcohol anion-exchange membrane and preparation method thereof

Abstract

The invention provides a polyvinyl alcohol anion-exchange membrane and a preparation method thereof. The polyvinyl alcohol anion-exchange membrane is prepared from quaternary polyvinyl alcohol, polydimethyldiallylammonium chloride, tetraethoxysilane and a cross-linking agent, wherein the weight ratio of the quaternary polyvinyl alcohol to the polydimethyldiallylammonium chloride is 1: (0.1 to 0.6). The polyvinyl alcohol anion-exchange membrane prepared by the preparation method provided by the invention is good in selective adsorption and high in adsorption capacity for chromium ions, free from secondary pollution after adsorption, as well as environment-friendly in raw materials and preparation process.

Description

technical field [0001] The invention belongs to the field of chemistry, and in particular relates to a polyvinyl alcohol anion exchange membrane. Background technique [0002] Cr(Ⅵ) belongs to the first class of pollutants, its toxicity is 100 times that of Cr(Ⅲ), it has great harm to the human body, and long-term intake may cause cancer. Chromium will not degrade by itself under natural conditions, and has a persistent danger to the environment. Chromium mainly comes from processes such as electroplating, tanning, printing and dyeing, and chromium salt production. The state has strict restrictions on the wastewater discharge of the above-mentioned enterprises, and the Cr (Ⅵ) discharge standard must be lower than 0.5mg / L. [0003] Cr(Ⅵ) is one of the common toxic heavy metals, especially in electroplating wastewater and leather wastewater. At present, the methods for removing Cr reported in the literature mainly include chemical adsorption, membrane interception, electroly...

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Problems solved by technology

The surface of the adsorbent in this method is loose and porous, rich in active groups such as amino groups, hydroxyl groups, and carboxyl groups, and can produce ion exchange, electrostatic or complex adsorption with Cr(Ⅵ), and has the advantages of low cost, simple preparation method, and good adsorption effect. , easy to control, etc., but the product after adsorption will form new solid waste and produce secondary pollutants

[0006] Chinese patent 200910312497.X discloses a method of using molecular template technology to prepare Cr ion (Cr ion) with chitosan, polyethylene glycol, etc. 6+ 、Cr 3+ ) is an adsorption resin with high selectivity and high adsorption, which is beneficial to the accurate enrichment of Cr ions, achieves the purpose of removing Cr ions and recycling, and can be used repeatedly, but the raw materials used in the preparation process of the resin such as methyl Acrylic, Cr 3+ etc. are toxic substances, which are easy to pollute the environment and cause harm to production personnel.

[0007] In summary, the methods used in the prior art for chromium removal have disadvantages such as poor selective adsorption of chromium, easy generation of solid waste after adsorption to form secondary pollution, and unenvironmental protection of raw materials and preparation processes.

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