Abstract：Studied the process and efficiency of desalination in FGD-gypsum as an improvement in coastal saline-alkali soil, analyzed the changes of soil’s aggregation and Hydraulic conductivity, and ion exchange process and effect of soil-gypsum system under different gypsum proportions (0%, 1%, 2.5%, 5%, and 10%) with the testing method of leaching aimed at characteristics of coastal saline-alkali soil in Shanghai. The result showed that soil aggregation has improved obviously, porosity has increased, soil hydraulic conductivity has enhanced, the average water diffusivity of soil was 4-5times than the control and sped the process of desalination effectively; ion exchange exhibited actively and the conductivity of eluent fell sharply as same as the concentration of ions in the beginning of 6days. Calcium ions exchanged sodium ions first in experimental groups, the average sodium removal efficiency was 1.8times than the control. Meanwhile, the exchanges of calcium-potassium and calcium-magnesium were going, but less than calcium-sodium. The efficiency of saline-alkali desalination depended on total exchangeable cations mainly in soil when gypsum ratio exceeded 1%. With the increase of gypsum proportion, marginal benefits of desalination were not significant. Finally, we recommended the mass ratio of FGD-gypsum and saline-alkali soil in the process of Shanghai saline-alkali soil improvement was close to 1% in a ideal condition of mixing thoroughly, the proportion could be appropriate to increase in field improvement project.
程镜润, 陈小华, 刘振鸿, 李小平, 付融冰, 陈泉源. 脱硫石膏改良滨海盐碱土的脱盐过程与效果实验研究[J]. 中国环境科学, 2014, 34(6): 1505-1513.
CHENG Jing-Run, CHEN Xiao-Hua, LIU Zhen-Hong, LI Xiao-Ping, FU Rong-Bing, CHEN Quan-Yuan. The experimental study on the process and effect to the FGD-gypsum as an improvement in coastal saline-alkali soil. CHINA ENVIRONMENTAL SCIENCECE, 2014, 34(6): 1505-1513.
