高砷地下水分布特征与形成机理研究

Study on distribution characteristics and formation mechanism of high arsenic groundwater

高砷地下水在全世界分布广泛,具有极强的化学毒性,给人类健康造成了极大的威胁,研究高砷地下水分布与形成机理是一项具有重要意义的世界性科学问题。本文对原生高砷地下水的分布进行统计及阐述,总结高砷地下水的分布特点及形成机理。结果可知:高砷地下水空间分布异质性强,主要分布在干旱或半干旱地区的内陆盆地与河流三角洲区域,整体上具有沿造山带分布的特点;含水层、沉积物以及地球化学条件是高砷地下水分布与形成最主要的影响因素,目前其形成机理主要包括竞争吸附机制、As(V)还原机制、铁锰氧化物的还原溶解和硫化物矿物氧化溶解;人类活动也影响着地下水中砷分布及全球地球化学循环,未来对人为活动对高砷地下水形成的影响研究是一个重要领域。本次研究结论丰富了地下水中砷迁移转化的理论成果,对地下水污染风险管控及水资源合理开发具有重要意义。

High-arsenic groundwater is widely distributed all over the world,has strong chemical toxicity,and poses a great threat to human health.Research on the distribution and formation mechanism of high-arsenic groundwater is a world-wide scientific issue of great significance.In this paper,the distribution of primary high-arsenic groundwater is analyzed and described,and the distribution characteristics and formation mechanism of high-arsenic groundwater are summarized.The results show that the spatial distribution of high arsenic groundwater is highly heterogeneous,mainly distributed in inland basins and river deltas in arid or semi-arid regions,and has the characteristics of distribution along orogenic belts as a whole.Aquifers,sediments and geochemical conditions are the most important factors affecting the distribution and formation of high-arsenic groundwater.At present,its formation mechanisms mainly include competitive adsorption mechanism,As(V)reduction mechanism,and reduction and dissolution of iron and manganese oxides and oxidative dissolution of sulfide minerals.Human activities also affect the distribution of arsenic in groundwater and the global geochemical cycle.Future research on the impact of human activities on the formation of high-arsenic groundwater is an important field.The conclusions of this study enrich the theoretical achievements of arsenic migration and transformation in groundwater,and are of great significance to the risk control of groundwater pollution and the rational development of water resources.