Removal of naphthalene present in synthetic waste water using novel Graphene /Graphene Oxide nano sheet synthesized from rice straw: comparative analysis, isotherm and kinetics

Abstract

Polycyclic Aromatic Hydrocarbons (PAHs) leads to negative effects towards the environment, which have carcinogenic and mutagenic properties affecting highly human being as well as the aquatic system. In this study, the main aim was to investigate the percentage removal of one of the PAHs i.e. naphthalene using (G) and (GO). Initially the Graphene Oxide was synthesized from rice straw obtained from local market of West Bengal. Prepared adsorbent was characterized by SEM, XRD, FTIR analysis. Removal efficiency of the synthesized graphene and graphene oxide at varying conditions like adsorbent dose, temperature, were studied. After certain interval, definite amount of samples were taken out, centrifuged and were analyzed using UV-visible spectrophotometer and HPLC. Higher removal at these condition was obtained at pH 7, temperature 30°C, and adsorbent dose 2 g/L for GO and at pH 6, temperature 30°C, and adsorbent dose 2 g/L for G. Maximum percentage removal was found to be 85% and 65% for G and GO respectively. Adsorption isotherm data were analyzed by Langmuir and Freundlich isotherm models and Langmuir isotherm was found to be best fitted for both G and GO. The process was found to follow the pseudo-second order kinetics in each cases.