Bentonite is a type of layered silicate clay mineral with montmorillonite as its main component. By using the ion exchange ability of bentonite, bentonite can exchange ions with simple metal ions and organic quaternary ammonium salt cations to achieve the purpose of modification. After modification, the physical and chemical properties such as inter-layer domains and adsorption properties have been significantly improved, and have received extensive attention in the field of environmental governance.
In view of the relatively weak status of development and application of bentonite in Ezhou, the basic physicochemical properties and types of bentonite from a certain place in Ezhou were studied in detail, and the sodium modification of the bentonite and the optimal process and conditions of organic intercalation were mainly studied for its performance index. The modified bentonite was applied in the treatment of Cu2+-containing and catering oil-containing wastewater. The adsorption performance of bentonite from Ezhou to heavy metal ions and organic oils in water was studied in detail. The purity of natural bentonite in Ezhou is not high, and the content of montmorillonite is 73.8%. In the modification and deep processing of bentonite, the content of montmorillonite is required to be more than 90%, so the purification of bentonite is particularly important. This time, it was purified by sedimentation purification process. By measuring the amount of blue absorption, the montmorillonite content after purification was increased to 93.4%. Through single-factor experiments, the better process conditions for sodium modification of bentonite were determined: sodium carbonate was a modification agent, the amount was 5%, the slurry concentration was 15%, and the stirring time was 15 minutes. The physicochemical properties of bentonite after sodium modification were significantly improved. The colloidal price and swelling capacity were increased from 100 mL/15 g, 11.0 mL/g to 500 mL/15 g, 72.0 mL/g, respectively. X-ray diffraction analysis showed d001 value. From the original 1.53 nm to 1.24 nm, Ca2+ in the interlayer region was exchanged with Na+ and changed from calcium bentonite to sodium bentonite. In the study of bentonite organic modification, the influencing factors of octadecyltrimethylammonium chloride (1831) modified bentonite were mainly studied, and a series of organic bentonites were prepared. According to the size of the interlaminar domain (ie d001 value) as an evaluation index of organic bentonite preparation effect, combined with the number of diffraction peaks, peak intensity, peak sharpness and peak symmetry to comprehensive evaluation. The optimum preparation process of organic bentonite was determined: the slurry concentration was 5%, the organic intercalation was washed 3 times, the coverage agent amount was 40%, the reaction temperature was 65°C, and the reaction time was 7 hours. After organic modification, its d001 value can reach 4.167 nm. The use of purified calcium bentonite, sodium bentonite and organic bentonite three powders as adsorbents, the adsorption of Cu2+ wastewater and simulated restaurant oily wastewater were studied systematically, and the heavy metal ions were compared through adsorption kinetic curves and adsorption isotherms. And oily wastewater adsorption properties.
The results showed that the sodium bentonite had the best adsorption effect on Cu2+ and the organic bentonite (1831-bentonite) had the best adsorption effect on the oil. In this thesis, a modification model of bentonite was established to explain the modification mechanism more clearly and clearly show the internal change process. In combination with infrared scanning technology, the adsorption process of organic bentonite on oil is clearly demonstrated, and the internal structure of the bentonite is explained through infrared spectra. This shows that the adsorption of organic bentonite on oil includes physical adsorption and chemical adsorption, mainly chemical adsorption.