Efficient Dye Decolorization of an Azo dye on Fish Scale Hydroxyapatite

Fish scales are excellent sources of calcium and phosphorous, that disposed every year as fishery waste from the fish industries and markets. Processing this abundant bio waste into some commercially important products could provide as an efficient fish scale remediation approach. Formulation of a commercial, effective dye-adsorbent concerned about its economical and renewability nature. This study demonstrated the capacity of hydroxyapatite, as adsorbent for removing an anionic dye congo red (CR) from aqueous solution. Hydroxyapatite (HAp) is an inorganic material, prepared from fish scale waste. The extracted adsorbent was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and fourier infrared spectroscopy (FTIR). SEM reveals agglomerated distribution of spherical HAp particles, while the structural analysis of HAp confirms by the position of strong peaks in XRD and FTIR spectrum. The decolorization of dye experiment was carried in batch adsorption mode. The influence of various parameters like pH of the solution, contact time, adsorbent dose, and initial dye concentration on the adsorption was determined. The optimum percentage of decolorization of CR was observed 98% using 2 g/L of adsorbent after 180 min. The results suggest a new possibility mode for the removal of dye from the textile effluent.