RESUMO
Red soil from Guangxi, China was selected as the background soil, and a porous biomorphic genetic composite of α-Fe2O3/Fe3O4/C comprising a bamboo template (PBGC-Fe/C) was used as a passivator to remediate As(â ¤) contaminated soils. The performance of PBGC-Fe/C was characterized by Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). The results showed that PBGC-Fe/C could improve the passivation effect of As(â ¤) from the contaminated soils compared with a single passivation material. Under the conditions of a 5% dose addition, 25% water content, and particle size of 100 mesh, the stability rates of PBGC-Fe/C on As(â ¤) contaminated soils with different concentrations of 500 mg·kg-1 and 1000 mg·kg-1 could reach 80.95% and 73.49%, respectively. The porous biomorphic genetic composite of bamboo charcoal provided a large number of adsorption sites for As(â ¤), and the acidity of the soil was favorable for the remediation of As(â ¤) via passivation. Moreover, PBGC-Fe/C could not only adsorb and fix As(â ¤), but also promoted the stabilization of As species. Chemical complexation and ion exchange played major roles in this passivation process.