RSM-CCD optimized sodium alginate/gelatin based ZnS-nanocomposite hydrogel for the effective removal of biebrich scarlet and crystal violet dyes

Abstract The present work represents RSM-CCD (Response Surface Methodology integrated Central composite Design) optimized synthesis scheme of semi-IPN (semi interpenetrating network) NaAla-Gel-cl-polyAAm and ZnS nanocomposite adsorbent NaAla-Gel-cl-polyAAm/ZnS. Under optimized reaction parameters semi-IPN NaAla-Gel-cl-polyAAm showed maximum swelling percentage of 3191.73%. Maximum dye removal percentage (97.37%) was observed with ZnS nanocomposite for the removal of biebrich scarlet. The adsorption isotherm data indicated that Langmuir and Freundlich adsorption isotherm fitted well for biebrich scarlet (R 2  = 0.964) and crystal violet (R 2  = 0.960), respectively. ΔG°, ΔH° and ΔS° values indicated the thermodynamic feasibility of the reaction. Excellent recyclability and reusability of the adsorbent materials suggested their applicability towards textile industry and water purification purpose.