Hen feather: a bio-waste material for adsorptive removal of methyl red dye from aqueous solutions

This study investigates the potential applicability of hen feather (HF) to remove methyl red (MR) dye from aqueous solution with the variation of experimental conditions: contact time (1–180 min), pH (4–8), initial dye concentration (5–50 mg/L) and adsorbent dose (3–25 g/L). Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) evaluate the surface morphology and chemistry of HF, respectively. The maximum removal of MR by HF was 92% when the optimum conditions were initial MR dye concentration 5 mg/L, pH 4, adsorbent dose 7 g/L and 90 min equilibrium contact time. Langmuir isotherm (R2 = 0.98) was more suited than Freundlich isotherm (R2 = 0.96) for experimental data, and the highest monolayer adsorption capacity was 6.02 mg/g. The kinetics adsorption data fitted well to pseudo-second-order model (R2 = 0.999) and more than one process was involved during the adsorption mechanism but film diffusion was the potential rate-controlling step. The findings of the study show that HF is a very effective and low-cost adsorbent for removing MR dye from aqueous solutions.