摘要：The age of groundwater is important in assessing renewability, recognizing movement and mass transport processes, and constraining model parameters of groundwater. In this study, we analysed the groundwater isotope (3H and 14C) of Shiyang River Basin, and estimated the groundwater age and its renewal rate. We found that the age of shallow groundwater in the Gobi zone was between five and ten years, and the age of groundwater in the piedmont region was about fifty years. However, the age of groundwater in the fine soil plain was more than fifty years, which was older than the groundwater in the Gobi zone and piedmont region. The renewal rate of shallow groundwater ranged from 0.0006% to 1.0% /a. In addition, the age of deep confined water shared an increased trend from the piedmont to rump. Specially, the youngest groundwater was in the piedmont with an age between 1000 and 2900 years, the groundwater age of the fine soil plain between 2920 and 3400 years, and the groundwater in rump region was more than 4000 years. The renewal rate of the deep groundwater was 0.0078-0.045‰ /a. The results suggested that shallow groundwater is younger than deep groundwater, and thus shallow groundwater is closely related to atmospheric precipitation with a shorter residence time and faster renewal rate than deep groundwater. In contrast to the shallow ratio of Zr/Mn, adsorbent dose and solution pH was investigated. The adsorption isotherm was emphatically investigated and thermodynamic parameters were calculated to better understand the adsorption mechanism.
