Effective Removal of Nitrotoluene Compounds from Aqueous Solution Using Magnetic-Activated Carbon Nanocomposites (m-Fe3O4@ACCs)

Abstract

In this study, regular-shaped magnetic-activated carbon nanocomposite (m-Fe3O4@ACCs) was synthesized and characterized with X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and the vibrating sample magnetometer (VSM) and was used as adsorbents for the removal of nitrotoluene compounds (NTCs) from water and industrial wastewater. The effective parameters on adsorption process, such as solution pH, shaking speed, contact time, and adsorbent dosage were optimized and the optimum amounts were 7 300 rpm, 10 min, and 1.2 g L–1, respectively. The contact time and adsorbent dosage are dependent parameters and hence were studied simultaneously. The results showed no significant loss in the adsorption capacity, and the adsorption efficiency of m-Fe3O4@ACCs could still be 90% in the 9th cycle. The equilibrium adsorption isotherm followed the Langmuir isotherm model describes the monolayer adsorption of NTCs on m-Fe3O4@ACCs, and the maximum adsorption capacities (qm) for 2-nitrotolouene, 2,6-dinitrotoluene, 2,4-dinitrotoluene, and 3,4-dinitrotoluene were found to be 144.93, 142.86, 166.67, and 153.85 mg g−l, respectively. The proposed process was successfully applied for the removal of NTCs from tap water and nitration process wastewater.