Highly efficient removal of acid red-17 and bromophenol blue dyes from industrial wastewater using graphene oxide functionalized magnetic chitosan composite

In present study, magnetic chitosan-graphene oxide composite (C-?-GO) has been synthesized and used for the removal of two common textile dyes; acid red-17 (AR-17) and bromophenol blue (BPB). The effect of various parameters including pH (2-8), time (10-100 min), adsorbent dosage (2-10 mg), initial dye concentration (2-30 gmL(-1)) as well as temperature (303, 313, and 323 K) was investigated. The point of zero charge of composite was determined using pH drift method in an attempt to better understand the adsorption process. Present work revealed fast adsorption kinetics with removal efficiency of around 79 and 97% for AR-17 and BPB, respectively, under optimized conditions. Besides, equilibrium relationships were studied using Langmuir and Freundlich models. Thermodynamic analysis uncovered the spontaneous and endothermic nature of dye-composite interation. Synthesized material showed profound stability after five successive adsorption-desorpion cycle of reuse. Importantly, spiked real water samples were used to check the suitability of composite adsorbent for practical applications. High % recoveries were obtained which indicated that complex matrix presented insignificant interference effects. Also, comparative study revealed that composite material offers superior performance for the removal of dyes relative to precursors (C, Fe3O4 nanoparticles, GO). Improvement in removal efficiency of synthesized composite toward selected dyes can be attributed to intrinsic qualities of C and incorporated functionalities; exceptionally high surface area as well as excellent mechanical properties of GO and convenience of magnetic separation because of Fe3O4 nanoparticles(.) POLYM. COMPOS., 39:3317-3328, 2018. (c) 2017 Society of Plastics Engineers