Performance of lead ion removal by the three-dimensional carbon foam supported nanoscale zero-valent iron composite

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 degrees 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 R-2 of 0.980, following the pseudo second order kinetics with a linear correlation coefficient R-2 of 0.988. A combination of multiple nano particles 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. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

In this study, nano-zero-valent iron (nZVI) particles were immobilized on carbon foam (CF) with a three-dimensional network structure, exhibiting superior adsorption capacity for Pb2+. The novel structure of CF-nZVI shows good dispersibility and potential for environmental remediation due to low cost and easy separation.