Study on efficient adsorption of mb by chitosan-polyvinyl alcohol composite hydrogels doped with nano-SiO2 and GO

This study used a straightforward one-pot method was accustomed to prepare a composite hydrogel prepared with polyvinyl alcohol (PVA) and chitosan (CS) as substrates doped with hydrophilic nano-sio2 and GO. The composition and structure of the composite hydrogel were characterized by SEM, XRD, XPS, etc, as well the tensile and compression tests were carried out. The effects of temperature, pH, concentration of adsorbent and other related parameters on adsorption properties were studied. Adsorption kinetics and the adsorption process was fitted using adsorption isotherm models of composite hydrogels. The results show that the hydrogel both has excellent mechanical characteristics, and has strong adsorption properties for methylene blue (MB) in dye wastewater. The maximum tensile strength of the composite hydrogel exceeds 1750kPa, the maximum tensile displacement is 300% of the initial form, and the maximum compressive strength exceeds 13000kPa. This is mainly due to the enhancement of nano-sio2 and the hydrogen bond interaction between the molecules. The optimum adsorption temperature of methylene blue was 55℃, pH was 7.0, and the concentration of adsorbent was 5%. PCG three-dimensional network structure composite hydrogel might be utilised as an inexpensive, sustainable and effective adsorbent for the removal of dye industry wastewater in textile industry, and has broad industrial application prospects.