【作者】 刘峰；

【导师】 陈家玮；

【作者基本信息】 中国地质大学（北京） ， 地球化学， 2010， 硕士

【副题名】以模拟软件Phreeqc应用为例

【摘要】 水-岩相互作用是地球科学领域十分关注的问题。多年来科学家们通过实验室内反复实验和野外观察,积累了大量的水-岩体系热力学和动力学参数,这为深入了解自然界水-岩作用现象和规律提供丰富的理论基础和实际数据资料。但这些工作一般都是通过化学反应测试获得,有很大的局限性。随着计算机科学的发展,通过建立适当的地球化学模型,用以模拟计算自然界中的水-岩相互作用,近年来国际上相关领域发展迅速。本文在地球化学反应平衡模拟理论基础上,建立了矿物溶解滴定模型,选用美国地质调查局（USCS）提供的Phreeqc模拟软件,研究了不同条件下,pH、温度、CO₂分压、离子强度等条件矿物溶解作用的影响。同时,在前人实地测试勘查的数据资料基础上,选择珠海校区的地下水-岩系统作为研究对象,通过软件计算,考察多种影响因素,进行了研究区的的水-岩地球化学反应模拟。模拟结果表明:（1）珠海校区地下水中典型矿物,如文石、方解石、白云石等都处于非饱和状态,由于这些矿物是灰岩的重要组成,其饱和指数均小于零,所以灰岩可能会持续溶解。（2）pH值、温度、二氧化碳分压、离子强度、同离子效应等因素的变化对于体系的平衡具有重要影响,文中对这些应影响作用进行了定量研究,发现温度、二氧化碳分压的影响满足一定的函数关系式。（3）研究了酸雨对水-岩作用的影响。模拟了Ca²⁺、NH₄⁺等离子对于典型矿物如文石、方解石、白云石等溶解反应平衡的影响。（4）模拟数据显示其地下水pH小于7,根据前人的实地调查数据资料,如果不加以控制处理,将会使其pH值进一步降低,将会给环境带来的潜在风险。更多还原

【Abstract】 Water-rock interaction is an attractive subject in earth sciences. Scientists have got a lot of thermodynamics and kinetics data of water-rock systems by means of experiments and investigations, which provide the basic theory and information to well understand water-rock interaction in the nature. However, these results are often obtained through geochemical analysis during reactions and this approach has many limitations. With the development of computer science, the study on rock-water interaction by geochemical modeling has been developed in recent years.Based on the theory of geochemical reaction equilibrium modeling, a kind of titration model was established in the thesis. The simulation software Phreeqc donated by USGS was used to study the mineral dissolution under different conditions such as pH, temperature, CO₂ partial pressure, ionic strength, etc. On the basis of data materials surveyed by others, groundwater-rock system in Zhuhai school zone was studied by geochemical reaction simulation.The results showed as follows. （1） Some minerals, such as aragonite, calcite, dolomite, were not saturated with groundwater. It indicated that limestone might be continued to dissolve. （2） The equilibrium of these systems was influenced by the factors including pH, temperature, CO₂ partial pressure, ionic strength and common-ion effect. It also indicated that temperature and CO₂ partial pressure have a relationship of mathematic functions with species. （3） The effect of acid rain was studied on water-rock interaction. It also showed ions such as Ca²⁺、NH₄⁺ would impact aragonite, calcite and dolomite dissolution equilibrium. （4） The simulation showed pH of groundwater would be less than 7, which might be a potential risk in the environment.更多还原