Aluminum-Tuned Porous Clay Heterostructures for Basic Blue-41 Removal: Adsorption Performance, Regeneration, and Batch Adsorber Design

The removal of colorant dyes from the environment is an urgent priority due to their toxicity and harmful effects on ecosystems. Porous clay heterostructures have been proposed as adsorbents for these dyes. In this study, aluminum porous clay heterostructures were developed using Al13-intercalated montmorillonites from a chlorhydrol solution. This method allowed us to tune the aluminum content incorporated into PCHs, with a maximum of 1.26 mmole/g of clay. The Al–porous clay heterostructures exhibited distinctive physicochemical properties, with higher surface area values in the range of 743–850 m2/g and acidity from 0.969 to 1.420 mmole of protons per gram of sample. The presence of Al in the PCH materials did not significantly disturb the porous structure or modify the removal properties of basic blue-41 dye. The effects of adsorbent dose (0.1–1 g), pH (2–11), starting BB-41 concentrations (25–500 mg/L), and contact time (5–2160 min) were evaluated during the batch process. A maximum dye removal percentage of 100% was achieved under optimal conditions of 50–100 mg/L BB-41, natural pH, and 0.050 g of solid/50 mL of solution. The Al amounts in the PCH materials affected the maximum removal capacity for basic blue-41, reaching 274 mg/g in PCH containing 1.16 mmole of Al/g of sample. The regeneration tests indicated that the Al–PCH materials retained 80 to 88% after three regeneration tests, and the efficiency was reduced to an average of 50% after the sixth test. The design of an efficient single-stage adsorber is theoretically proposed based on the mass balance equation and the Langmuir, Freundlich, and Sips isotherm parameters.