No abstract

No abstract

No abstract

The adsorption of Toluidine Blue (TB) cationic dye was performed using raw and treated (thermal, chemical, thermo-chemical, ultrasonic) diatomite. Solid samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (EDX), and Fourier Transformed Infrared Spectroscopy (FTIR). Adsorption experiments were performed in batch conditions (20 ± 2°C, 100 mg TB/L, 100 mL, 0.1 g adsorbent). The best sample proved to be the one thermally treated at 250°C for 2 h with an adsorption capacity of 7.97 mg/L and 77% removal efficiency. The regeneration process of the used diatomite was also performed (calcination, HCl, water), the most efficient was the one using water. Kinetic models (pseudo-first-, pseudo-second-order, liquid film, and intra-particle diffusion) were considered to describe the experimental data. The calculated data showed that liquid film diffusion might be rate-determining step in this case.

Co-, Ce-, and Ni-doped carbon xerogels (Me-CX) synthesized by sol-gel method followed by an ion exchange process were used as catalysts for catalytic wet air oxidation (CWAO) of phenol. The prepared catalysts were characterized using TEM, SEM, BET surface area, and XRD. Me-CX catalysts were tested in mild conditions (20-60 °C, atmospheric pressure) in a semi-batch reactor in various reaction conditions (30-60 L/h, 0.05-0.2 g catalysts, 50-175 mg phenol/L). Total organic carbon (TOC) removal efficiency values obtained decrease in the following order Co-CX ≅ Ce-CX > Ni1-CX > K-CX for the catalysts obtained using the same procedure. TOC removal efficiencies of up to 72% were reached in case of Co-CX catalyst at 20 °C, 40 L/h, using 0.15 g catalyst and a solution of 100 mg phenol/L.