Single-loop octane enrichment.

Abstract

The tendency to agglomeration and the difficulty in recycling of nano-zero-valent iron (nZVI) has been a major gap hindering its practical utilization. In this study, for the first time, nZVI particles were immobilized on carbon foam (CF) with a macroscopic three-dimensional (3D) network structure through an annealing process following NaBH4 reduction. The as-fabricated CF-nZVI exhibit a superior adsorption capacity of 335.4 mg g−1 for Pb2+ (conditions: 10 mg, 200 mg L−1, 25 °C and pH = 6), which is associated with the abundant adsorption sites (functional groups, i.e. –OH and –COOH) and effective mass transfer resulted from the interconnected porous network structure. The adsorption of Pb2+ by CF-nZVI can be described by the Langmuir isotherm adsorption model with R2 of 0.980, following the pseudo second-order kinetics with a linear correlation coefficient R2 of 0.988. A combination of multiple nanoparticles forms a novel vinca-like structure, which demonstrates a good dispersibility and avoids the massive reunion of nZVI. Given that advantages including low cost, excellent adsorption capacity and the facile separation of 3D porous monolith, CF-nZVI composites can be selected as a potential candidate for environmental remediation.