深部CO2泄漏对浅层地下水水质影响研究进展

由于盖层中存在的未知断层、裂隙或被废弃井穿透等原因,深部储存的CO₂可能会发生渗漏,并向上迁移进入浅部含水层,改变地下水中酸度和溶解组分的浓度分布。国外开展CO₂泄漏对浅层地下水水质影响相关研究尚处于起步阶段,且室内实验、野外试验和数值模拟等研究结果表明,CO₂泄漏对浅层地下水中pH和微量重金属组分浓度影响显著,虽浓度大多未超饮用水标准,但由于含水介质之间矿物组成的差异较大,有必要针对具体场地的地下水水质和矿物组分特征进行调查,研究CO₂侵入对地下水水质的影响,在总结已经达成共识和存在的问题基础上提出下一步研究趋势。

Advances in deep CO2 leakage impact on shallow groundwater quality

Due to the existing faults, fractures and penetrating wells in the cap rock, the deep stored CO₂ can leak into a shallow aquifer, change the acidity and the distribution of hazard components concentration in groundwater. According to the literature, the studies in this area are in their infancy, and the results from lab and field experiments, numerical simulations and natural analogues studies show that, the intrusion of CO₂ into a shallow aquifer would decrease the pH and elevate the trace metal components concentrations significantly. However, the concentrations rarely exceed the drinking groundwater limits. Because of the significant differences between the mineralogy in different aquifers, detailed studies should be done on the risk assessment of carbon dioxide leakage of special aquifers, and point out that further study is needed based on the limitations of the current studies.