Magnetic perovskite nanohybrid based on g-C3N4 nanosheets for photodegradation of toxic environmental pollutants under short-time visible irradiation.

In this study, a magnetic perovskite nanohybrid based on g-C3N4 (gCN) nanosheets was synthesized and developed for the efficient photodegradation of toxic environmental pollutants under short-time visible irradiation. The synthesis of this nanohybrid involved the incorporation of SrTiO3:N (STO:N) and ZnFe2O4 (ZnF) onto the g-C3N4 nanosheets through a simple reflux method. Our investigation encompassed a comprehensive suite of analytical techniques, including BET, TGA, TEM, SEM, EDX, DRS, VSM, XRD, photocurrent, and FT-IR, to elucidate the physicochemical characteristics of this nanocomposite in the context of its application in photodegradation processes. The nanohybrid displayed significantly enhanced photocatalytic activity compared to its individual components, achieving a degradation efficiency of over 90% for various pollutants, including organic dyes like Rhodamine B (Rh-B), within a short irradiation time. This enhanced activity can be attributed to the synergistic effect between gCN, STO:N, and ZnF, which promotes the generation of reactive oxygen species and facilitates the degradation process. Notably, the nanocomposite containing 20 wt% STO:N perovskite and 20 wt% ZnF demonstrated the highest Rh-B degradation rate under visible light irradiation within just 30 min. Furthermore, the nanohybrid displayed excellent stability and reusability over seven consecutive runs, retaining its high photocatalytic activity even after multiple cycles of degradation. This remarkable performance can be attributed to the strong interaction between the gCN nanosheets and the magnetic perovskite components, which prevents their aggregation and ensures their efficient utilization. Additionally, the nanohybrid exhibited excellent visible light absorption, enabling the utilization of a wider range of light for degradation. This feature is particularly advantageous, as visible light is more abundant in sunlight compared to UV light, rendering the nanohybrid suitable for practical applications under natural sunlight. In conclusion, the ternary gCN-STO:N@ZnF nanocomposite represents a promising candidate for the treatment of organic pollutants in aqueous environments, offering a versatile and efficient solution.

Response surface methodology optimizing the adsorptive removal of azithromycin using mesoporous silica SBA-15: Mechanism, thermodynamic, equilibrium, and kinetics modeling studies.

The objective of this research was to study an effective adsorbent for removing azithromycin (AZT) from industrial wastewater. AZT is an antibiotic used for many diseases remedy, but it is a pollutant to our environment; therefore, its residual should be removed from wastewater. The mesoporous SBA-15 silica as an efficient adsorbent was prepared by the hydrothermal method. The surface of mesoporous SBA-15 plays a significant role in the removal process; therefore, the characterization of the adsorbent was accomplished by several techniques. The batch system has been used, and the effect of four essential variables: pH (3-10), drug concentration (20-200 mg L-1), sorbent weight (0.2-2 g L-1), and temperature (20-40 °C) were investigated on the AZT removal efficiency by response surface methodology (RSM). The isotherm results were found to be in proper compliance with the isotherm model of Freundlich. In the kinetics part of this study, the experimental outcomes were fitted to the equation model of pseudo-second-order. The calculation of thermodynamic parameters shows that the removal process is spontaneous and endothermic. Upon the results, the vast surface area, the active functional groups, reusability, stability, and inexpensively make the mesoporous SBA-15 a suitable candidate for removal of AZT and similar antibiotics.

Keratin nanoparticles obtained from human hair for removal of crystal violet from aqueous solution: Optimized by Taguchi method.

Developing the cheap but superior adsorbents is of importance for environmental applications. In this paper, the Taguchi experimental design was applied to establish the optimum condition for the removal of crystal violet (CV) dye using keratin nanoparticles obtained from human hair waste. The average diameter of keratin particles was found about 63.7 nm, using DLS. Effective factors on the removal of CV dye including pH, adsorbent dose, temperature and contact time were considered using an L16 orthogonal array. The optimum condition was found to be pH = 9, adsorbent dose = 0.004 g, temperature = 25 °C and contact time = 10 h in the studied range for different parameters. ANOVA results indicated that the pH has the highest contribution percentage (75.97%) on the adsorption process. Moreover, the equilibrium data were well described by Freundlich Isotherm, indicating a multilayer adsorption process with a maximum adsorption capacity of 555.56 mg/g through an endothermic and spontaneous adsorption process that could be used for up to 5 cycles of adsorption process. The kinetic adsorption data were evaluated by different kinetic models, where the data followed a pseudo-second-order model with three steps of diffusion indicated by the intra-particle diffusion model. The obtained results clearly show the high potential of human hair-obtained keratin nanoparticles for removal of cationic dyes from wastewater.