Résumé:
This study investigates the potential of adsorption photocatalyse coupling (AC/TiO2/UV) as a promising solution for efficient removal of textile dyes from industrial wastewater. The study begins by developing, characterizing, and evaluating the effectiveness of adsorbents prepared from locally available biomass (in this case, opuntia ficus - indica cords). The production method studied consists of chemical activation with H3PO4 and KOH, followed by pyrolysis at 600 °C. The adsorbents were characterized by a series of physicochemical analyses, including spectroscopy (FT-IR, XRD, XRF and SEM-EDX), thermal analysis (DTA/TGA) and chemical analysis (Boehm method, pHPCN, iodine number). The surface morphology of ACH3PO4 and ACKOH is irregular and heterogeneous, with a well-developed porous structure. The performance of the adsorbents (OFIC, ACH3PO4, and ACKOH) for RB dye adsorption was evaluated, and kinetic studies revealed that linear and nonlinear pseudo-second-order models best described the adsorption of the prepared materials. The obtained thermodynamic parameters show that the adsorption system (ACH3PO4/RB) is a spontaneous endothermic process with increasing randomness. (ACKOH/RB) and (OFIC/RB) are non - spontaneous exothermic processes with decreasing randomness. To investigate the adsorption mechanism of textile dyes, both linear and nonlinear isotherm models were employed. The findings indicate that the Freundlich and Toth models are more suitable for the (ACH3PO4/RB) system, while the Langmuir and Redlich-Peterson models exhibit better adequacy for the (ACKOH/RB) system. Additionally, the Temkin and Sips models prove to be more appropriate for the (OFIC/RB) system.
The RB dye used in the experiment underwent photodegradation under specific conditions, including a concentration of 70 mg/L, a solution height of 0.6369 cm, room temperature, a UV power of 16 W/365 nm, a stirring speed of 300 rpm, and a catalyst mass ratio (TiO2)/mass of AC) of 0.01g/0.5g. Different systems were utilized, including TiO2/UV, TiO2/UV/H2O2, TiO2/AC/UV, and TiO2/AC/UV/H2O2. The results of the TiO2/CA/UV/H2O2 coupling process show that the solution is almost completely decolorized, the removal efficiency is 96.38%, and the energy consumption is 584.79kWh/m3. This system is known for its high treatment efficiency and low cost, making it a promising solution for the treatment of textile dyes in industrial wastewater.
