Disparate soil textures as a native medium for As(V) and Pb(II) separation from aqueous systems

Abstract

This study investigated the use of different natural raw soil materials as low-cost adsorbents for the removal to remove As(V) and Pb(II) from aqueous systems. It deals with the effect of different soil textures, sandy loam, loam, and loamy sand, on adsorption efficiency. Fourier-transform infrared spectroscopy (FTIR) was used to carry out the comprehensive characterization of materials, as well as scanning electron microscopy (SEM), X-ray diffraction (XRD), and liquid nitrogen porosimetry or the Brunauer–Emmett–Teller (BET). Studies were performed in a batch system; the initial concentration of examined heavy metals was 100 μg·L–1, pH varied in the range of 4–6, and the adsorbent dosage was 5–20 mg/10 mL. Sandy loam was the most efficient adsorbent for As(V) separation, with a maximum removal efficiency of 47.5%, while the loam was the most efficient for Pb(II) separation, with a maximum removal efficiency of 94.2%. The removal efficiency was affected mainly by the adsorbent characteristics. Performed kinetic studies revealed two steps of adsorption for both investigated ions. Obtained results indicate that natural sorbents used in this work present environmentally sustainable material for As(V) and Pb(II) removal, on the one hand, and the basis for further studies on the simultaneous removal of heavy metals from water and their reduced mobility in soil, on the other.