High efficient Hg (II) and TNP removal by NH2 grafted magnetic graphene oxide synthesized from Typha latifolia

Abstract

ABSTRACT The present study for the first time manifests the outstanding potential of amine grafted magnetic graphene oxide (m-GO-NH2) synthesized from Typha latifolia stems for mercury (Hg (II)) and 2,4,6-trinitrophenol (TNP) removal. The adsorption performance of m-GO-NH2 was apprized by considering the impact of the contact time (0–120 min), pH (2–9), adsorbent dose (5–40 mg), and adsorbate concentration (10–50 mg/L). The maximum Hg (II) and TNP removals (∼ 100%) were obtained using 30 mg adsorbent dose in 90 and 75 min, respectively. The best performance of m-GO-NH2 was observed at pH of 7, 20 mg/L Hg (II), and pH of 2, 30 mg/L TNP. According to the Brunauer–Emmett–Teller (BET) analysis, the surface area of GO was 34.81 m2/g and the simultaneous micro and mesoporosity was observed. Regarding the thermodynamic studies, the adsorption procedure was spontaneous and endothermic for Hg (II) followed Redlich-Peterson (R-P) and Freundlich isotherm equations while it was exothermic for TNP, well fitted with Langmuir and R-P isotherms. Kinetic data also indicated a good correlation with pseudo-second-order model. The highest adsorption capacity was estimated as 107.33 and 105.2 mg/g for Hg (II) and TNP, respectively. Accordingly, the proposed m-GO-NH2 can be a promising adsorbent for the elimination of metal and organic contaminants.