CAJ | 학술논문

针对上海滨海盐碱土的特点,借助土柱淋洗试验方法,研究了脱硫石膏改良滨海盐碱土的脱盐过程与效果,分析了不同石膏质量配比条件下(0%,1%,2.5%,5%和10%),土壤团粒结构和水力传导度变化以及盐碱土-脱硫石膏体系中的离子交换过程与效率.研究结果表明：加入脱硫石膏之后,盐碱土团粒结构得到改善,孔隙度变大,水力传导能力增强,平均导水系数是对照组的4~5倍,有效加快脱盐过程；在土柱开始淋洗的前6d 内,离子交换过程表现最活跃,淋洗液的电导率和离子浓度急剧下降.添加脱硫石膏的土柱中钙离子优先置换出钠离子,平均脱钠效率达到对照组的1.8倍.钙钾离子交换和钙镁离子交换也同步发生,但规模明显小于钙钠离子交换.当脱硫石膏质量配比超过1%时,盐碱土的脱盐效果主要取决于原土中的交换性阳离子总量.随着配比增加,盐碱土脱盐的边际效益增加量并不显著.在充分混匀的理想条件下,建议上海滨海盐碱土改良过程中添加脱硫石膏的质量配比高于1%为宜.
침대상해빈해염감토적특점,차조토주림세시험방법,연구료탈류석고개량빈해염감토적탈염과정여효과,분석료불동석고질량배비조건하(0%,1%,2.5%,5%화10%),토양단립결구화수력전도도변화이급염감토-탈류석고체계중적리자교환과정여효솔.연구결과표명：가입탈류석고지후,염감토단립결구득도개선,공극도변대,수력전도능력증강,평균도수계수시대조조적4~5배,유효가쾌탈염과정；재토주개시림세적전6d 내,리자교환과정표현최활약,림세액적전도솔화리자농도급극하강.첨가탈류석고적토주중개리자우선치환출납리자,평균탈납효솔체도대조조적1.8배.개갑리자교환화개미리자교환야동보발생,단규모명현소우개납리자교환.당탈류석고질량배비초과1%시,염감토적탈염효과주요취결우원토중적교환성양리자총량.수착배비증가,염감토탈염적변제효익증가량병불현저.재충분혼균적이상조건하,건의상해빈해염감토개량과정중첨가탈류석고적질량배비고우1%위의.
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.