Efficient Removal of Cationic and Anionic Dyes from Their Binary Mixtures by Organic-Inorganic Hybrid Material

The present work reports the efficiency of a hybrid nanocomposite material towards removal of few cationic (Crystal Violet, Methylene Blue, Light Green) and anionic dyes (Neutral Red and Eriochrome Black T) as a sole or from their binary mixtures by adsorption. The nanocomposite has been obtained by dispersion of polyaniline into an inorganic matrix of zirconium(IV) phosphoborate by sol-gel method. Experiments were carried out as a function of pH of the solution, adsorbent dosage and time interval, to achieve maximum adsorption. The maximum adsorption capacity of the composite for methylene blue, crystal violet and neutral red was found to be 71.42, 89.97, 56.0 mg g(-1), respectively at pH 11, and 72.70 mg g(-1) for Eriochrome black T and 83.74 mg g(-1) for light green at pH 3. The adsorption phenomenon has been validated by plotting Langmuir and Freundlich adsorption isotherms. The adsorption of all the selected dyes was well described by pseudo-first-order kinetics. The percentage adsorption and recovery of the dye has been found to be high enough for first three batches. As water is contaminated with a number of dyes, the sole nanocomposite capable of eliminating whole dye content, may serve as a boon for water remediation.