模拟酸雨对石灰岩的破坏和表面腐蚀  

Simulated acid rain on the deterioration of calcite and it’s surface corrosion

作　　者：徐飞高[1,2] 汤剑[1] 高士祥[1] 

机构地区：[1]污染控制与资源化研究国家重点实验室//南京大学环境学院,江苏南京210093 [2]南昌大学理学院,江西南昌330047

出　　处：《生态环境》2008年第6期2445-2449,共5页Ecology and Environmnet

基　　金：江苏省社会发展项目课题(BS2006050)

摘　　要：硫酸是酸雨中腐蚀石灰岩的最主要成分，以不同pH值（4．0，5．6）的稀硫酸溶液模拟酸雨对石灰岩进行淋溶处理，研究不同酸度酸雨对石灰岩腐蚀的影响，包括溶液中pH值变化，Ca^2＋离子浓度变化、石灰岩表面粗糙度变化、重量损失和表面结构变化。结果表明，不同酸度酸雨淋溶后石灰岩都受到一定程度的影响，随着模拟酸雨酸度的增大，Ca^2＋的释放量呈上升趋势；Ca^2＋溶出速率，与H^＋的消耗速率不呈现明显的相关关系；经过120h酸雨淋溶后，石灰岩重量损失率在0．083％-0．25％。酸雨淋溶后石灰岩表面结构产生了腐蚀，表面粗糙度增加，孔隙变深变宽，并在一定程度上缓解了酸雨的进一步腐蚀。表明高酸度雨水对南京六朝石刻等石灰岩建筑有影响。Because sulphuric acid is the major component of acid rain responsible for corrosion of calcite, it is possible to simulate the deterioration of stone inscriptions exposed to acid rain with dilute sulphuric acid solution. The changes of pH values and Ca^2＋ concentration in the solution, material losses of calcite, and surface corrosion have been studied by washing calcite samples with sulphuric acid solution at different pH （4.0, 5.6）. The results showed that as acidity of the simulated acid rain increased, the release of Ca^2＋ from calcite tended to increase. However, the dissolving rate of calcium ions was not evidently correlated with consuming rate of hydrogen ions. Material losses of the calcite were 0.083%-0.25% after 120 hr eluviation of simulated acid rain. The surface of crystal structure was corroded. The surface roughness increased, and the pores were deepened and widened in the case of sulphuric acid washing for 24 h. The limestone appeared to be less susceptible to the further elution of acid rain after corrosion. The results have indicated that low pH acid rain had significant impact on the stone inscriptions of six dynasties in Nanjing.

关 键 词：硫酸 石灰岩 腐蚀 酸雨 循环泵 

分 类 号：X517[环境科学与工程—环境工程]