Study On Flue Gas Desulfurization Gypsum In Reclamation Of Sodic Soil

The saline soil that is an important land resource extensively distributed on the earth, it's area total about 1 billion hectares, which is about 25 percent of land area. There is approximately 27 million ha saline-alkali soil land in our country. The saline soil is distributed extensively, which the main salt content is the chloride, the structural property and fertility is poor, Therefore it is difficult to increase agricultural production.Along with continuous and rapid development of Chinese economy, as well as implementing of the project of flue gas desulfurization(FGD)of coal-burning powerplants in "Twain Control Zone"-the zone of acid rain controlling and the zone of sulfur dioxide(SO₂)controlling, the outputs of FGD gypsum is going to rise continuously. As coal combuistion products, multipurpose use of FGD gypsum, it not only reduce the mining quanlity of nature gypsum and pertect the natural gypsum resource, increase the saleroom of FGD gypsum products, answer for sustainable development stratagem of China, and it possesses important real significance.The change of soil physical and chemical properties with different amount of by-product from flue gas (FGD) applied is researched .The effect of sodic soils reclamation was investigated using by-product from FGD and searched for the optimal quantity of soil amendment due to the improvement of sodic soils. The effect of soil reclamation was observed by using four soil samples from Yinchuan of Ningxia and Ordos of Inner Mongolia at four levels (i.e. the amount of by-product from FGD is 0.5wt%, 1.0wt%, 1.5wt%, and 2.0 wt%). As a result, soil pH and ESP decreased and this result indicates that by-product from FGD has the effect of improving sodic soil physical and chemical properties. In the certain range (0～2.0 wt%), the amelioration effect of sodic soil presents positive correlation with the applied amount of by-product from FGD. If the amount exceeds the range, the better effect of the soil reclamation could not be attained and a great deal of salt will be accumulated in soil and it will be more difficult to improve the sodic soil. In terms of this experiment result, the optimum range of applied amount is 0.5wt%～1.0wt%.