以锂同位素线索示踪高砷地下水物质来源

The Lithium isotopes, as an emerging stable isotope tracing method has become a unique tracer agent for special groundwater material with its unique sensitivity for water-rock reaction and other outstanding features. Typical high arsenic groundwater distribution area of Hetao plain, Inner Mongolia will be selected as studying object to explore the fractionation properties of lithium isotopes representing the water-rock reaction, and get the fractionation mechanism of lithium isotopes during the forming process of high arsenic groundwater by combining the Strontium, D-180, 3H, 14C isotope and traditional hydrogeochemistry method; then build up the lithium isotopes mixed model. Marking all the material end member of high arsenic groundwater in the studied area and the contribution of each end member by using the Lithium isotopes clues, combining the Strontium, D-180, 3H, 14C isotope and other hydrogeochemistry method to do the multi dimensional isotopes trace for groundwater arsenic source, and explore the source, migration, enrichment and the transformation mechanism of the material of high arsenic groundwater in studied area.

锂同位素作为新兴的稳定同位素示踪手段，以其对水-岩作用的敏感性及其具有的一些其他显著特点，成为近年来特殊类型地下水物质来源的独特示踪剂。本次研究选取内蒙古河套平原高砷地下水典型分布区，探索表征水-岩反应的锂同位素分馏特征，结合锶、D-18O、3H、14C同位素及传统水文地球化学方法，确定高砷地下水形成过程中锂同位素的分馏机制，建立锂同位素混合模型。以锂同位素为线索，标定研究区高砷地下水的物源端元及各端元的贡献，结合锶、D-18O、3H、14C同位素及其他水文化学参数，进行地下水砷来源的多维同位素示踪，对研究区高砷地下水的物质来源、迁移、富集和转化机理进行探索。