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| Study on adsorption of hexavalent chromium in soil |
| WANG Yuxue1,2, TONG Juxiu1,2*,LI Bijun1,2 |
| 1. Key Laboratory of Groundwater Cycle and Environment Evolution, China University of Geosciences, Ministry of Education, Beijing 100083, China; 2. Collage of Water Resources and Environment Sciences, China University of Geosciences, Beijing 100083, China |
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Abstract In order to study the adsorption rule of chromium(VI)under different initial pH and initial concentration conditions, the dynamic adsorption test of soil column was carried out on the soil of Wuhan Dongxihu vegetable base. Six soil samples with different properties were prepared by adjusting the initial solution pH values and concentrations. Origin software was used to fit the penetration curve of solute. The diffusion coefficient of inertia Cl- was calculated by tracer experiment, and the solute transport parameters of Cr(VI)in the soil were determined by numerical simulation combined with the chemical non-equilibrium model in CXTFTI software. The adsorption process of Cr(VI)in the soil was analyzed and predicted. The results show that the adsorption of Cr(VI)is very sensitive to the pH value. The lower the initial pH value of the solution is, the earlier the penetration time and the adsorption saturation time are. The initial concentration affects the adsorption of chromium(VI), too, specially, the higher the initial concentration of the solution is, the earlier the penetration time and the adsorption saturation time are. The solute transport parameters of Cr(VI)in the soil determined by the two-point model can well explain the results in the soil column experiment. For example, about 60% of the adsorption process of Cr(VI)in the soil completes instantly, and 40% is restricted by the rate, which satisfies the first-order kinetic equation.
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Received: 10 December 2018
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