Fabrication of Novel Magnetic Graphene Oxide Nanoadsorbent from Strychnous potatorum Seeds for Enhanced Removal of Chromium from Wastewater

The main aim of the study is to synthesize graphene oxide from natural source (by utilizing Strychnous potatorum seeds) and composite with iron oxide to form magnetic graphene oxide (MGO) which has been applied as adsorbent for removal of chromium from wastewater. The prepared MGO adsorbent has been characterized by FTIR, XRD, VSM, UV-visible and SEM to examine its structural, morphology, elemental and chemical composition. The average particle size of MGO from SEM image is 47.2 nm and analysis results show the successful oxidation of GO and well distribution of magnetic iron oxide particles onto GO. Batch method has been opted for adsorption process and the operation parameters are optimized. The adsorbent MGO exhibits maximum removal rate of 97.1% for chromium under optimized conditions. An adsorbent dose of 10 mg shows maximum efficiency in the adsorption process. Adsorption Isotherm and kinetic behaviour are investigated and founded that Freundlich adsorption isotherm model are well suited for chromium (R²=0.996) and the adsorption behaviour are well explained by pseudo second order which followed by chemisorption. The maximum adsorption capacity (q_max) exhibited by this novel MGO adsorbent is 9.09 mg/g. Desorbing agent NaOH is used for desorption process. Only 17.1% efficiency is reduced even after 5 cycles of adsorption-desorption and proved can be reuse. This novel MGO adsorbent is easily separated after the adsorption process. From the study, it is concluded that this neoteric MGO adsorbent as a promising, super-eminent candidate for wastewater treatment.