Activated carbonaceous materials from tea waste and its removal capacity of indigo carmine present in solution: synthesis, batch and optimization study

The present work determines efficiency of domestic food waste like tea waste in removing indigo carmine from synthetic textile wastewater. Carbonaceous material (tea waste) has been employed and it showed removal percentage of indigo carmine at 90% through adsorption process. Carbonaceous material was chemically activated by using modified Hummer's method and it was observed through Scanning Electron Microscopic image, Fourier Transform Infrared Spectrometer, X-ray diffractometer and Brunauer, Emmett and Teller analysis that revealed that the modified biochar is comparably similar to graphene oxide (GO). Various experimental parameters are evaluated for the removal efficiency of the synthesized adsorbent under the present study. Results of the experiments performed using the GO-like adsorbent synthesized from tea waste confirmed potential efficiency of adsorption of indigo carmine dye from synthetic waste water solution. The adsorption mechanism has been analysed by fitting the experimental data in different adsorption isotherm and kinetic models. The results indicated that the adsorption followed Langmuir isotherm model with maximum uptake of 20 mg g(- 1) and pseudo second order kinetic model with the best correlation coefficient. The thermodynamic study showed the dye removal to be spontaneous and endothermic.