Adsorptive removal of toxic azo dye Amido Black 10B by hen feather

PURPOSE AND AIM: Amido Black 10B is an azo dye with very high toxicity. It is now established that the dye damages the reparatory system of humans and also causes skin and eye irritations. It is therefore considered worthwhile to develop a systematic procedure to eradicate Amido Black 10B from its aqueous solution using a waste material as adsorbent. Therefore, adsorption of the dye is achieved using hen feathers as adsorbent.

Before using hen feather as adsorbent material, it is washed, cut into small pieces and activated using hydrogen peroxide. Detailed chemical and physical analysis of hen feather was also carried out by known analytical techniques. The adsorptive removal of the dye was made through batch experiments in 100 mL airtight flasks. The experiment is divided in three major categories, the preliminary investigations, adsorption isotherm measurements, and kinetic studies.

Under preliminary investigations, the effect of pH, temperature, concentration of dye, and amount of adsorbent were carried out. It was found that with increase in pH, the adsorption of Amido Black 10B decreases; while with increasing the amount of hen feather, it increases. The isothermal studies indicate that the ongoing adsorption process is endothermic in nature and obeys Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevitch (D-R) adsorption isotherm models. The Gibb's free energy and entropy of the adsorption were also calculated. The D-R isotherm model verified the involvement of chemisorption during the adsorption. The kinetic measurements indicate operation of pseudo second order process during the adsorption and dominance of film diffusion mechanism at all the temperatures.

The developed method is highly efficient and ecofriendly. It also ascertains a necessitous utilization of waste material hen feather for the benefit of the society.