Abstract
2,4-Dichlorophenol (2,4-DCP) is a hazardous chlorinated organic chemical derived from phenol that exerts serious effects on living organisms. In the present study, SnO2 templated with grapefruit peel carbon as a nanocomposite (SnO2@GPC) was designed via ball-milling, and its mechanism of 2,4-DCP adsorption in aqueous solution was determined. Batch adsorption experiments revealed that the maximum adsorption efficiency of SnO2@GPC occurred at 6.0 pH, 3 mg L-1 initial adsorbate concentration, 2 h contact time, and 293 K temperature. The SnO2@GPC nanocomposite and its non-tin-bearing counterpart, grapefruit derived char (@GPC), showed maximum adsorption capacities (Q(L)) of 45.95 and 22.09 mg g(-1) and partition coefficients of 41.77 and 10.83 mg g(-1) mu M-1 - respectively. The adsorption of 2,4-DCP was best described by the Redlich-Peterson model followed by the Langmuir model with high correlation coefficients (R-2 >= 0.96), and the adsorption kinetic data best fitted the pseudo-second-order model (R-2 >= 0.98). The thermodynamic parameters indicated that the reaction was spontaneous, exothermic, and involved high affinity between SnO2 @GPC and 2,4-DCP. The high desorption efficiency obtained ( > 80%) demonstrated the recyclability of the adsorbent. The enhanced Q(L) of SnO2@GPC was due to the effective combination of GPC and SnO2. A thin porous layer of GPC on SnO2 nanoparticles provided effective channels, a large surface area, and an abundance of active sites for 2,4-DCP adsorption. Thus, the SnO2@GPC nanocomposite could potentially be used as a low-cost adsorbent to remove 2,4-DCP from water.