Fabrication of starch-graft-poly(acrylamide)/graphene oxide/hydroxyapatite nanocomposite hydrogel adsorbent for removal of malachite green dye from aqueous solution

The biocompatibility, biodegradability, porosity, water content and water uptake of the synthesized NHAs were also evaluated. The NHA was employed as bioadsorbents for the adsorption of MG dye. The temperature dependence data also revealed that MG sorption process was feasible, spontaneous and endothermic. The MG adsorption rates were described by the pseudo-second-order model. Furthermore, the adsorption isotherm data fitted well with the Langmuir isotherm model with a maximum adsorption capacity of 297 mg g−1 for MG dye. The NHA also showed an excellent regeneration capacity after five consecutive cycles of dye adsorption-desorption. According to the results, the prepared NHAs could be environment friendly and promising adsorbents for the adsorption of different cationic dyes from contaminated water.