Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1016/j.scitotenv.2020.144670
Titel (primär) Utilization of pit Lake on the cleaning process of residual saltwater in unconfined coastal aquifers
Autor Zhang, B.; Zheng, T.; Zheng, X.; Walther, M.
Quelle Science of the Total Environment
Erscheinungsjahr 2021
Department ENVINF
Band/Volume 770
Seite von art. 144670
Sprache englisch
Topic T5 Future Landscapes
Keywords Seawater intrusion; Numerical models; Subsurface dam; Unconfined coastal aquifers; Pit lake
Abstract Subsurface dams are widely used to prevent saltwater intrusion. Once a subsurface dam is established, a large amount of residual saltwater (RSW) may trap behind the dam and negatively affect the groundwater exploitation over the long term. Based on monitoring hydrological information and field-scale numerical models, we proposed three kinds of RSW clean-up strategy coupling the applications of a pit lake and wells in a coastal aquifer. We firstly investigated the spontaneous natural removal of RSW in an actual coastal aquifer affected by a pit lake, assessed the impact of pit lake drainage on the removal of RSW, and designed a feasible strategy for reducing residual saltwater utilizing both pit lake and wells. Our results indicated that RSW remediation is a slow process under natural conditions. The area of the RSW decreased from 15.17 to 11.62 km2 after 20 years, and the Cl concentration of RSW around the pit lake increased to 1750 mg/L. The RSW cleaning efficiency can be significantly enhanced by the pit lake drainage process. With the pit lake drainage rate of 1.6E5 m3/d, the area of the RSW decreased by 10.14 km2 in five years being 17-times larger than that of the natural restoration scheme (0.58 km2). With the combined well-lake drainage system, the total residual saltwater area decreased by more than 90% within five years, and the Cl concentration of RSW almost reached WHO standards for drinking-water quality (250 mg/L). RSW upstream the subsurface dam was thoroughly cleaned up adopting the well–lake drainage strategy. Therefore, a well–lake drainage strategy can be strongly recommended for removing the RSW in coastal aquifers.
dauerhafte UFZ-Verlinkung
Zhang, B., Zheng, T., Zheng, X., Walther, M. (2021):
Utilization of pit Lake on the cleaning process of residual saltwater in unconfined coastal aquifers
Sci. Total Environ. 770 , art. 144670 10.1016/j.scitotenv.2020.144670