Comparative Studies of Regeneration and Single Batch Design for the Properties of Basic Blue-41 Removal Using Porous Clay and Porous Acid-Activated Heterostructures

In this investigation, the parent clay mineral montmorillonite (Mnt) was acid activated using sulfuric acid (H2SO4) at a specific mass of acid to clay mineral of 0.2 (A-Mnt) prior to the preparation of the porous clay heterostructure precursor. The derived porous acid-activated clay heterostructure (PACH) exhibited properties different from those of the conventional one (PCH). The synthesized materials were characterized using different physiochemical techniques, such as X-ray fluorescence (XRF), powder X-ray diffraction (XRD), thermogravimetric analysis (TA), 29Si MAS-NMR, nitrogen adsorption–desorption, and acidity using cyclohexylamine (CHA) as a probe molecule. The PACH had a surface area of 890 m2/g and an acidity of 0.56 mmol of protons/g. An evaluation of PCH materials was conducted to assess their effectiveness in removing basic blue 41 (BB-41) from aqueous solutions. The removal process was analyzed based on the initial concentration and pH of the BB-41 solution, and the amount of solid used, employing a batch approach. The removal efficiency was found to be greater at higher pH values, specifically between six and nine. Using the Langmuir model, the maximal removal capabilities of the studied materials were determined to be between 274 and 300 mg/g. According to the results of the regeneration tests, PACH materials could still be employed after seven cycles with a 25% efficiency loss and a 50% efficiency loss for PCH materials. Utilizing the Langmuir model equations and mass balance, a single-stage batch design was suggested to estimate the required masses to remove BB-41 at different percentages from a starting concentration of 200 mg/L.