浙江瑶琳洞风化碳酸钙景观复生试验中CO_2吸收动力学研究

DYNAMICS OF ABSORBING CO_2 IN THE RECOVERING EXPERIMENT OF WEATHERED SPELEOTHEM IN YAOLIN CAVE, ZHEJIANG, CHINA

在H2O—CO2—CaCO3 的系统中,因喀斯特水中逸出CO2,导致CaCO3 沉积,形成千姿百态、琳琅满目的洞积物,如石笋、钟乳石、石林、石葡萄、卷曲石等等。由于洞穴环境的变化,使洞穴沉积石产生严重的风化作用。然而,我们试用钙碱性溶液吸收CO2,产生CaCO3 沉积,可使风化的洞穴碳酸钙景观恢复其美学价值。碱性溶液吸收CO2 的静态试验表明,溶液CO2 的吸收过程主要发生在前8 个小时,对浓碱溶液来讲,前4 个小时最重要。动态试验结果说明,碱性溶液吸收CO2,沉积CaCO3 的过程主要发生在60 cm 流程内。试验中,滴水速度小的吸收CO2 及沉积CaCO3 率高于滴水速度快的碱性溶液。当一滴溶液变成薄膜流时,它吸收CO2 的能力将提高24.34 倍。

In the system of H 2O-CO 2-CaCO 3, the release of CO 2 from karst water will result in the precipitation of CaCO 3 to form the varieties of speleothems such stalatctites, drapery, grapes, helictites etc.. Since the cave was opened to the public, a great number of visitors have rashed into the cave under different lights, and the ecologic and environmental system in the cave has been greatly changed and the speleothem landscape has been suffered to be seriously weathered. As a result, the scientific and aesthetic values of the speleothems have been descended. We tried to recover the weathered speleothems by the absorbing CO 2 of the Ca 2+ alkalinity solutions in Yaolin Cave, Zhejiang. The static experiments showed that the absorbing CO 2 of the Ca 2+ alkalinity solutions to precipitate CaCO 3 mainly took place in the initial 8 hours, but it was very important for the concentrated solution in the initial 4 hours. The dynamic expriments showed that the absorbing CO 2 of the solution predominantly took place in 60cm when it flowed on the weathered speleothems. The drops with the low velocity absorb more CO 2 than the fast drops. When the drops become the film flow, the absorbing CO 2 efficiency of alkalinity solution to deposit CaCO 3 will been increased by 24.34 times.