An efficient sonophotocatalytic degradation of reactive blue 19 (RB 19) dye was successfully carried out using sulfur-doped TiO2 (S-TiO2) nanoparticles. The effect of various treatment processes that is sonolysis, photolysis, catalysis, sonocatalysis, photocatalysis, and sonophotocatalysis were investigated for RB 19 removal. S-TiO2 were synthesized in 1, 3 and 5 wt.% of sulfur by sol-gel process and characterized by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX), UV-Visible diffuse reflectance spectra (DRS). The results confirm anatase phase of TiO2, porous agglomerate structure, and a red shift in the absorbance spectra of S-TiO2. The dye degradation was studied by using UV-Vis spectrophotometer at λ max=594 nm. The reaction parameters such as pH, catalyst dosage, initial dye concentration, ultrasonic power and effect of sulfur doping in different weight percent were studied to find out the optimum degradation conditions. Optimum conditions were found as: S-TiO2=5 wt.%, catalyst (S-TiO2 5 wt.%)=50mg, RB 19 solution concentration=20 mg L(-1), pH=3, ultrasound power=100 and operating temperature=25°C. The response of 5 wt.% S-TiO2 was found better than 1 and 3 wt.% S-TiO2 and other forms TiO2. The sonophotocatalysis process was superior to other methods. During this process the ultrasound cavitation and photocatalysis water splitting takes place which leads to the generation of OH. As reveled by the GCMS results the reactive blue 19 (20 mg L(-1)) was degraded to 90% within 120 min. The S-TiO2 sonophotocatalysis system was studied for the first time for dye degradation and was found practicable, efficient and cost effective for the degradation of complex and resistant dyes such as RB19.

Recent advances in tissue engineering have potential for the development of improved substitutes for damaged skin tissues. Vitamin C and lactic acid are well-known wound healing accelerators while chitosan is an important biomaterial having wound healing capabilities. However, addition of vitamin C induces fragility to the chitosan–lactic acid membranes. Therefore, the current study was designed to fabricate an intact chitosan–vitamin C–lactic acid composite membrane that may synergize the critical properties of every individual component for potential skin tissue engineering. For this purpose, different concentrations of glycerol and polyethylene glycol (PEG) were added to strengthen the chitosan–vitamin C–lactic acid membranes. The prepared membranes were characterized by Fourier transform infrared spectroscopy, X–ray diffraction, and field emission scanning electron microscopy. Moreover, the biocompatibility of the prepared membranes was evaluated with fibroblast NIH 3T3 cells. The results showed that addition of glycerol and PEG has improved the strength of chitosan–vitamin C–lactic acid composite membrane. Characterization studies revealed the successful synthesis of chitosan–vitamin C–lactic acid composite membrane. Moreover, the prepared membranes showed excellent biocompatibility with NIH 3T3 cells. However, it is important to note that cells showed more attachment and spreading on porous chitosan composites membranes as compared to nonporous membranes. This study provided a base for the development of an intact chitosan–vitamin C–lactic acid composite membrane for skin tissue engineering. However, further preclinical and clinical studies are required for its practical applications in skin tissue engineering.

Background: Guar gum is a water-soluble polysaccharide called galactomannan, obtained from the endosperm of Cyamopsis tetragonolobus, plant belonging to Leguminosae family. Galactomannan is a biopolymer rich in functional groups, particularly hydroxyl groups, which expand the possibilities of its chemical modification and, therefore, of biological applications. Objective: This review aims to present and discuss various methods used in the preparation of guar gum composites and their applications in biomedical, pharmaceutical, food and cosmetic industry. Methods: The published data about the extraction procedure of guar gum and its various physico-chemical properties have been collected and analyzed. Further, the published information about various methods used for the preparation of guar gum composite systems including film, hydrogel and beads have been gathered and comprehensively discussed in this review. The applications of guar gum based composites in the field of biomedical, pharmaceutical, food and cosmetics have also been reviewed in detail. Results: Different guar gum composite systems have shown multifunctional properties, including gelling and emulsifying ability, thickening and binding property, quick solubility in water, good biocompatibility, and biodegradability in the domain of biomedical, pharmaceutical, food, and cosmetic industries. Conclusion: Recent advancements in the preparation and applications of guar gum composites summarized in this review will enhance the practical applications of this polymer in various industries.

Present study was conducted to investigate the adsorption and ultrasound-assisted adsorption potential of silver nanoparticles (AgNPs) and silver nanoparticles loaded on chitosan (AgCS composite) as nano-adsorbents for methylene blue (MB) removal. AgNPs were synthesized using leaf extract of Ligustrum lucidum, which were incorporated on the chitosan’s surface for modification. UV–Vis Spectroscopy, FTIR, XRD, SEM, and EDX techniques were used to confirm the synthesis and characterization of nanomaterials. Batch adsorption and sono-adsorption experiments for the removal of MB were executed under optimal conditions; for fitting the experimental equilibrium data, Langmuir and Freundlich’s isotherm models were adopted. In addition, the antimicrobial potential of the AgNPs and AgCS were examined against selected bacterial and fungal strains. UV–Vis spectroscopy confirmed AgNPs synthesis from the leaf extract of L. lucidum used as a reducer, which was spherical as exposed in the SEM analysis. The FTIR spectrum illustrated phytochemicals in the leaf extract of L. lucidum functioning as stabilizing agents around AgNPs and AgCS. Whereas, corresponding crystalline peaks of nanomaterial, including a signal peak at 3 keV indicating the presence of silver, were confirmed by XRD and EDX. The Langmuir model was chosen as an efficient model for adsorption and sono-adsorption, which exposed that under optimum conditions (pH = 6, dye initial concentration = 5 mg L⁻¹, adsorbents dosage = 0.005 g, time = 120 min, US power 80 W), MB removal efficiency of AgNPs was >70%, using ultrasound-assisted adsorption compared to the non-sonicated adsorption. Furthermore, AgNPs exhibited promising antibacterial potential against Staphylococcus aureus with the maximum zone of inhibition (14.67 ± 0.47 mm). It was concluded that the green synthesis approach for the large-scale production of metallic nanoparticles is quite effective and can be recommended for efficient and cost-effective way to eradicate dyes, particularly from textile wastewater.

Phenol is the most common organic pollutant in many industrial wastewaters that may pose a health risk to humans due to its widespread application as industrial ingredients and additives. In this study, waste green tea leaves (WGTLs) were modified through chemical activation/carbonization and used as an adsorbent in the presence of ultrasound (cavitation) to eliminate phenol in the aqueous solution. Different treatments, such as cavitation, adsorption, and sono-adsorption were investigated to remove the phenol. The scanning electron microscope (SEM) morphology of the adsorbent revealed that the structure of WGTLs was porous before phenol was adsorbed. A Fourier Transform Infrared (FTIR) analysis showed an open chain of carboxylic acids after the sono-adsorption process. The results revealed that the sono-adsorption process is more efficient with enhanced removal percentages than individual processes. A maximum phenol removal of 92% was obtained using the sono-adsorption process under an optimal set of operating parameters, such as pH 3.5, 25 mg L⁻¹ phenol concentration, 800 mg L⁻¹ adsorbent dosage, 60 min time interval, 30 ± 2 °C temperature, and 80 W cavitation power. Removal of chemical oxygen demand (COD) and total organic carbon (TOC) reached 85% and 53%. The Freundlich isotherm model with a larger correlation coefficient (R², 0.972) was better fitted for nonlinear regression than the Langmuir model, and the sono-adsorption process confirmed the pseudo-second-order reaction kinetics. The findings indicated that WGTLs in the presence of a cavitation effect prove to be a promising candidate for reducing phenol from the aqueous environment.