Abstract: Chromium is a trace element and toxic effect will be caused by excessive intake of chromium. Factors including the concentration of Cr(III), reaction time, reaction temperature and pH value were studied to investigate the adsorption behavior of loess soil towards Cr(III). The researches indicated the adsorption speed is very fast; the adsorption capacity of Cr(III) on loess soil is very big; and the adsorption test results can be well interpreted by three isotherm models, i.e. Freundlich and Dubinin-Radushkevich (D-R) models. The thermodynamic analysis indicates that the adsorption process of Cr(III) on loess soil is spontaneous, and higher temperature is benefit to the adsorption process. Higher temperature leads to higher adsorption capacity; higher initial concentration of Cr(III) leads to higher adsorption capacity too; pH value has great influence on the removal efficiency of Cr(III) from aqueous solution, and Cr(III) can be nearly completely removed at pH>6. X-ray diffraction spectra and Fourier transform-infrared spectra were used to further discuss the adsorption mechanism of Cr(III) on loess soil; and the analysis indicates that the clay minerals such as kaolin and quartz and organic matter in loess play important roles in Cr(III) removal.

Key words: chromium, loess soil, heavy metal contamination, adsorption