Ultrasonic-assisted adsorption of propyl paraben on ultrasonically synthesized TiO2 nanoparticles loaded on activated carbon: optimization, kinetic and equilibrium studies

In deleting dyes from aqueous solutions, the applicability of TiO2 nanoparticles loaded on activated carbon (TiO2 NPs-AC) synthesis has gained attention. The focal attention of this paper was directed at the development of an operative methodology to procure the best possible removal conditions through the instrumentality of ultrasonic to maximize the deletion of propyl paraben dye with the lowest deleting errors. Through the use of response surface methodology (RSM), propyl paraben dye could load up onto TiO2 nanoparticles loaded on activated carbon (TiO2 NPs-AC) in aqueous solution in no time. Certain techniques in particular Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy were employed to characterize this unique material. Also, the impacts of variables including initial propyl paraben concentration (X-1), pH (X-2), adsorbent dosage (X-3), sonication time (X-4) came under scrutiny using central composite design (CCD) under RSM. The influences of variables such as initial propyl paraben concentration (X-1), pH (X-2), adsorbent dosage (X-3), sonication time (X-4) investigated by CCD under response surface methodology. The process was empirically modeled to reveal the significant variables and their possible interactions. The optimization conditions were set as: 3 min, 4.0, 0.027 g, 12 mg L-1 for ultrasound time, pH, adsorbent mass, propyl paraben concentration, respectively. Finally, it was found that the equilibrium and kinetics of the adsorption process follow the Langmuir isotherm and pseudo-second-order kinetic model, respectively. The adsorbent was proved to be recyclable for more than once. Since almost 99.5% of propyl paraben was deleted with ideal adsorption capacities (Q(max)) was found to be 120 mg g(-1) for propyl paraben at optimum conditions. Therefore not only the short-time adsorption process was considered an advantage but also other advantages in using TiO2 nanoparticles loaded on activated carbon (TiO2 NPs-AC) such as being recyclable, safe and cost-efficient made it a promising and powerful material for the wastewater treatment.