科研之友
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摘要
The mechanism for reclaiming sodic soils using calcium sulfate (CaSO4) could provide a theoretical basis for the field application of CaSO4 substitutes, including the by-products of flue gas desulfurization (BFGD), fly ash, and phosphorus gypsum. In this study, Ca2+ application experiment was conducted to analyze the dynamic changes of the cations in the reclamation of sodic soils with CaSO4. A multicomponent solute transport model (UNSATCHEM) that considers ion adsorption exchange and dynamic changes in the soil's hydraulic conductivity was subsequently used to simulate and predict the movement of ions. The Ca2+ application experiment consisted of four treatments with four CaSO4 concentrations (0.5, 1, 1.5, and 2 g L-1). When the Ca2+ concentrations in the supplied water were 14.71, 22.06, and 29.41 mmol L-1, Ca2+ achieved penetration, and this process was faster when the Ca2+ concentration in the supplied water was higher. Ca2+ did not achieve penetration when the Ca2+ concentration was 7.35 mmol L-1. UNSATCHEM was able to simulate the transportation mechanism of Ca2+ and Na+ in the soil solution in the Ca2+ application experiment, the adsorption and exchange between the Na+ in the soil colloid and Ca2+ in the soil solution, and the precipitation and dissolution of CaSO4 with a high degree of accuracy. Sodic soil reclamation with CaSO4 was not a short-term process. Compared with applying CaSO4 only once, applying CaSO4 in batches decreased the accumulation of soil salts and promoted its dissolution.
- 出版日期2014-7
- 单位中国地质大学（北京）; 中国农业大学
