Removal of methylene blue from aqueous solution by adsorption on pyrophyllite

- Pyrophyllite is an efficient adsorbent for removing methylene blue from water.
- Modification of pyrophyllite improves the adsorption capacity and increases MB adsorption.
- Adsorption kinetic is described by the pseudo-second-order kinetic model.

The effectiveness of adsorption for dye removal from solutions has made it an ideal alternative to other expensive treatment methods. The ability of raw and pickling-grinding modified pyrophyllite powders to adsorb methylene blue has been investigated in this study by looking at the dependence of absorption on pH values, adsorbent mass and the initial methylene blue concentration. The measured D50 of raw particles was 21.42 μm, which was decreased to 7.18 μm after grinding treatment, and to 5.55 μm after pickling-grinding. We showed that the raw and modified pyrophyllite powders have a high adsorptive capacity for dyes. The absorption ability of raw and modified pyrophyllite powders decreased with the increase of the initial methylene blue concentration in solution, while increased with the pH value. Increase in the adsorption with adsorbent mass was attributed to increase adsorbent surface area and availability of more adsorption sites. The adsorption capacity of raw powders reached 3.71 mg/g, and the numbers of pickling, grinding and pickling-grinding powders increased to 3.83 mg/g, 3.94 mg/g and 4.24 mg/g, respectively.