冻融过程中污染物在湖泊冰水双介质体系迁移作用及机理研究

Freezing and thawing caused the lake water phases change, the mechanism is the function of hydrogen bonds between water molecules, and this process is in the company of energy conversion. Energy is the one of important driving factors of physical motion. So, energy gradient is caused by freeze-thaw action and will lead to substance movement. Taking Ulansuhai Lake of Inner Mongolia as our research area, firstly, it analyzes the characteristics of energy conversion and ice-water dual media structural in process of freezing and thawing. Secondly, based on first-principles, it calculates ion’s adsorption capability in two water phases and binding energy of same ion, and compares substance structural stability in the ice-water dual media. Then, according to the difference in certain ion’s concentration of two media, it works out the theory transport capacity of the ions. Further, coupling these two energy systems of water phase change and ion’s transportation in ice- water medium, and using the water quality data from simulation experiments and field monitoring, revises and verifies the theoretical parameters of transportation. In conclusion, it discloses the unique characteristics of contaminants transport during the freezing and thawing in cold area lakes, and reveals the contaminant transport capacity and contribution on freeze-thaw effect. So, it provides a scientific foundation of cold area lakes environmental protection and management for choosing the best time and optimum plan.

冻融作用引起湖泊冰、水双介质相互转化，其机理是水分子中氢键的缔合与断裂，在此过程中伴随着能量转化，能量又是推动物质运动的唯一驱动因素，因此冻融作用造成的能量梯度必然引起物质迁移运动。项目以内蒙古乌梁素海湖泊为研究区，首先，分析冻融过程中冰、水介质结构变化及能量转化特征。然后，通过第一性原理计算液态水与固态水对同一离子的吸附作用及结合能，进而比较物质在冰、水双介质体系中的结构稳定性，获得同一离子在两种环境下吸附浓度的差异，计算冻融过程双介质中的理论迁移量。进一步，将冰、水转化过程的能量值与物质在两种介质中的结合能进行耦合关联，通过实验模拟及实地监测的冰、水介质特征指标进行理论迁移量的参数修订与验证。最终，摸清寒区湖泊在冻融过程中污染物独特的迁移特征，明确由冻融作用引起污染物迁移的能力与贡献作用，为寒区湖泊环境保护、治理的最佳时间与方案制定提供科学依据。

冻融作用引起湖泊冰、水双介质相互转化，其机理是水分子中氢键的缔合与断裂，在此过程中伴随着能量转化，能量又是推动物质运动的唯一驱动因素，因此冻融作用造成的能量梯度必然引起物质迁移运动。项目以内蒙古乌梁素海湖泊为研究区，分析了冻融过程中冰、水介质结构变化及能量转化特征。通过第一性原理计算液态水与固态水对同一离子的吸附作用及结合能，并比较不同离子在冰、水双介质体系中的结构稳定性，获得同一离子在两种环境下吸附浓度的差异，计算冻融过程双介质中的理论迁移量。利用物质在两种介质中的结合能及物质分配系数计算了不同离子在冰、水介质间的迁移量。得出了寒区湖泊在冻融过程中污染物独特的迁移特征，明确由冻融作用引起污染物迁移的能力与贡献作用。