Tetrabutylammonium Impregnated Chitosan for Adsorptive Removal of Harmful Carcinogenic Dyes from Water-Bodies

The chitosan biopolymer was impregnated with quaternary ammonium salt tetrabutylammonium bromide to enhance adsorption capacity of the material. The synthesized material, tetrabutylammonium impregnated chitosan (TIC) was characterized using various spectral techniques such as Fourier Transform Infra-red spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) along with energy dispersive X-ray spectrum for elemental composition (EDAX), Thermo-gravimetric analysis (TGA-DTA) and pH point of zero charge (pH(PZC)). The pH(PZC) of the material was found to be 8.2 which indicated that both anionic as well as cationic dyes can be adsorbed on its surface. Thus TIC was employed as adsorbent for the removal of two dyes namely, malachite green (MG) and methylene blue (MB). The effects of operational parameters such as pH of dye solution, contact time, adsorbent dose, adsorbate concentration and temperature on the adsorption process were studied using batch adsorption method. The adsorption process was found to follow Freundlich isotherm model and maximum adsorption capacities were found to be 56.1 mg g(-1) and 30.5 mg g(-1) for MG and MB respectively at pH 8.5. Pseudo-second order kinetic model was found to be the best-fit model and thermodynamic studies showed that the process of adsorption is spontaneous and enthalpy driven in nature. [GRAPHICS] .