Sodium Docusate Surface-Modified Dispersible and Powder Zinc Peroxide Formulation: An Adsorbent for the Effective and Fast Removal of Crystal Violet Dye, an Emerging Wastewater Contaminant
Sachin Sachin, Deepak Joishar, Netra Pal Singh, Netra Pal Singh, Ezhilselvi Varathan, Nahar Singh, Nahar Singh
Abstract
Crystal violet (CV) dye is one of the most toxic dyes majorly generated by textile industries. It may cause health issues if enters human beings. A lot of research has been reported for the removal of CV dye from wastewater; however, most of them are time-consuming and hardly remove more than 95% of the CV dye. In the last few years, we have tested several materials, and most of them have exhibited very low efficacy toward adsorption of CV including zinc peroxide (ZnO2). To enhance adsorption efficacy, dispersibility, and stability, the surfaces of several reported materials were modified using different wetting agents and nonionic surfactants. Interestingly, ZnO2, which was earlier very less effective after surface modification by sodium salt of dioctyl sulfosuccinate, efficiently adsorbed >99.5% of CV from contaminated water within 5 min of contact time at pH ∼10. The adsorption capacity obtained for the sodium docusate surface-modified zinc peroxide (ZnSD) adsorbent was found to be 123 mg/g, which is much better than the other reported for CV removal. Different physiochemical experiment parameters like pH, contact time, initial dye concentration, adsorbent dosages, and temperature were optimum to achieve maximum adsorption of the CV dye. The adsorption rate and adsorption mechanism studies show that the adsorption of CV follows pseudo-second-order kinematics and the Freundlich isotherm model. The adsorption results are consistent, and even treated water can be reutilized for various applications.