Thiol functionalized attapulgite and preparation method thereof

Abstract

The invention belongs to the technical field of heavy metal passivation, discloses thiol functionalized attapulgite and a preparation method thereof. The preparation method comprises: placing pre-treated attapulgite into a mixed solvent, and ultrasonically treating by using an ultrasonic wave system to uniformly disperse the attapulgite in the mixed solvent; carrying out pretreatment impurity removal on the raw attapulgite; dissolving gamma-trimethoxysilylpropanethiol (MTS) in absolute ethanol, and adding water and PEG400 to obtain a mixed solvent; carrying out a stirring reaction for 7-8 h ina stirrer, and carrying out centrifugal separation on the sample after the reaction to remove the upper layer aqueous solution and retain the solid-state substance; and washing the solid-state substance with distilled water to achieve a neutral state, and carrying out vacuum drying for 10-12 h at a temperature of 60-80 DEG C to obtain the thiol functionalized attapulgite. According to the presentinvention, the thiol is grafted by using the silane coupling method, such that the new approach is provided for the research and development of heavy metal contaminated soil passivating agents with advantages of large adsorption capacity, environmental friendliness and good adsorption selectivity.

Description

technical field [0001] The invention belongs to the technical field of heavy metal passivation, and in particular relates to a mercapto-functionalized attapulgite and a preparation method thereof. Background technique [0002] Currently, the closest prior art: [0003] Attapulgite (also known as palygorskite) is a natural clay mineral with layer chain transition structure mainly composed of hydrous magnesium-rich silicate. Attapulgite has excellent ion adsorption performance, large specific surface area and dispersion performance, and has broad application prospects in passivation restoration of heavy metal contaminated soil. However, the attapulgite raw ore has limited adsorption capacity for heavy metals, and the adsorption selectivity and adsorption force are not strong. Therefore, it is the key to solve the problem to develop a modified attapulgite passivator with high efficiency, wide application range and low cost. [0004] Studies have shown that mercapto groups ha...

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Problems solved by technology

[0017] Attapulgite raw ore has limited adsorption capacity for heavy metals, and the adsorption selectivity and adsorption force are not strong

The existing technology does not carry out ultrasonic control on the attapulgite, which makes the uniformity of the prepared product inconsistent, affects the adsorption effect, and ultimately results in poor repair effect on contaminated soil

[0018] In the prior art, PEG-20000 is dissolved in a solid form and dispersed in a mixed solvent, and affected by external adjustments, it will cause uneven dispersion of PEG-20000, resulting in a decrease in the performance of the final product

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