Study On Saline Alkali Soil In Hetao Irrigation Area Soil Testing And Application Of Desulfurization Gypsum Technology

In view of the existing desulfurization gypsum improving saline alkali soil in Hetao Irrigation Area in the process of problem, this paper studied through indoor soil column leaching simulation test on the effect of application of FGD gypsum and gypsum on the earth the depth. The results are as follows:1) Calcium ameliorates alkaline earth and non-leakage mixed layer can effectively slow calcium, non-mixed layer can reduce the loss of the calcium ion. In the improved process of alkali, sodium ion is greatly reduced after the first slow down until cannot detect the sodium ions exist.2) Dissolved gypsum with soil depth increases, the amount of gypsum dissolution50cm column in the9.71cmol/L, the largest amount of dissolution, the dissolution rate of up to75.80%. Dissolved gypsum first filtrate of each column is the biggest,15cm column gypsum dissolution first filtrate volume accounts for the proportion in the gypsum dissolution for26.54%.3) The soil column gypsum residue situation is different,50cm within the soil column gypsum residue at least, for3.10cmol/L, the residual rate was24.20%,30cm soil column gypsum residue maximum is5.93cmol/L, and the residual rate was46.24%.15cm and40cm depth soil column gypsum residue similarity, while20cm and30cm depth soil column similar gypsum residue. Residues are gypsum fertilizer and gypsum dissolution amount of difference, therefore, and gypsum dissolution amount of contrary.4) The soil column plaster leakage, leakage of15cm gypsum soil column5.00cmol/L maximum leakage rate of63.19%. The50cm column there is almost no gypsum leakage. Gypsum leakage15cm soil column each filtrate is small, relatively stable, gypsum leakage rate at around2%. The20cm column of gypsum5filtrate leakage rate of not more than1%, the maximum leakage of gypsum content was0.10cmol. the maximum leakage rate of1.43%gypsum. Gypsum leakage with soil depth increases, increases with the number of copies increase filtrate.5) Transformation of the soil column in different15cm gypsum, Gypsum Conversion soil column and the conversion rate is the lowest.2.91cmol/L and36.81% respectively. The50cm column conversion of gypsum and the highest conversion rate was9.69cmol/L and99.74%respectively. Conversion rate of gypsum dissolution and alkaline substances, the role of volume, associated with the dissolution amount and the leakage of gypsum, gypsum conversion volume increases with increasing depth of soil column.6) Gypsum improvement of alkaline soil with gypsum dosage should be considered in alkaline salt, sodium carbonate, sodium bicarbonate, magnesium carbonate, bicarbonate magnesium consumption of gypsum content, also want to consider the exchange of ions on the consumption of gypsum, including exchangeable sodium, exchangeable magnesium. Application of gypsum amount of alkali salts and exchangeable sodium, magnesium exchange gypsum content consumption and.7) Gypsum having improved effect for different depth soil alkalization soil column, each has a different degree of de alkali. The15cm column alkalization rate52.68%, de alkali, alkaline improved1.73%, reaches the goal of improvement. The soil column desalting effect is obvious, the desalting rate decreases with the increase of soil column depth, but the desalination rate greatly reduced.