High-efficiency adsorption of methylene blue dye from wastewater by a thiosemicarbazide functionalized graphene oxide composite

With the aim of developing an improved adsorbent material for the treatment of printing and dyeing wastewater, we prepared a novel thiosemicarbazide functionalized graphene oxide (GO-TSC-GO) adsorbent by condensation reaction of the thiosemicarbazide amino group with the graphene oxide carboxyl group. This material was characterized by SEM, XPS, FTIR, Raman, XRD, UV-Vis, TGA, and BET then used to conduct adsorption experiments on simulated printing and dyeing wastewater containing methylene blue (MB). We investigated the effects of temperature, time, pH, salt ionic strength, initial MB solution solubility, and the activation and regeneration of the adsorbent on adsorption performance. The adsorption behavior was consistent with the pseudo-second-order adsorption kinetic model and the Langmuir adsorption isotherm model. Thermodynamic analysis indicated an exothermic chemical adsorption reaction. In addition, the GO-TSC-GO exhibited excellent reusability. The maximum adsorption capacity of GO was 196.8 mg/g whereas the maximum adsorption capacity of GO-TSC-GO was 596.642 mg/g, verifying that the GO-TSC-GO composite has important applications for the treatment of printing and dyeing wastewater.