TY  - JOUR
AU  - Qi, H.
AU  - Ma, C.
AU  - He, Z.
AU  - Hu, X.
AU  - Gao, L.
PY  - 2019//
TI  - Lithium and its isotopes as tracers of groundwater salinization: A study in the southern coastal plain of Laizhou Bay, China
T2  - Sci Total Environ
JO  - The Science of the Total Environment
SP  - 878
EP  - 890
VL  - 650
IS  - Pt 1
KW  - Brine and seawater intrusion
KW  - Groundwater salinization
KW  - Hydrochemistry
KW  - Lithium isotope
KW  - Southern coastal plain of Laizhou Bay
N2  - In the southern coastal plain of Laizhou Bay, due to intensive exploitation of groundwater since the early 1970s, the shallow aquifer has been severely influenced by saltwater intrusion, which causes the extraction to shift from shallow to deeper aquifer changing the hydrogeological condition greatly. This study was conducted to investigate the groundwater salinization using hydrochemistry and H, O and Li isotope data. Dissolved Li shows a linear correlation with Cl and Br in seawater, brine and saline groundwater indicating the marine Li source, whereas the enrichment of Li in surface water, brackish and fresh groundwater is impacted by dissolution of silicate minerals. The analyses of hydrochemistry and isotopes (H, O and Li) indicate that brine originated from seawater evaporation, followed by mixing processes and some water-rock interactions; shallow saline groundwater originated from brine diluted with seawater and fresh groundwater; deep saline groundwater originated from seawater intrusion. The negative correlation of δ(7)Li and Li/Na in surface water, brackish and fresh groundwater is contrary to the general conclusion, indicating the slow weathering of silicate minerals and hydraulic interaction between surface water and shallow groundwater in this area. The analyses of hydrochemistry and isotopes (Li, H and O) can well identify the salinity sources and isotope fractionation in groundwater flow and mixing, especially groundwater with high TDS. As both mixing with saltwater and isotope fractionation can explain the combination of high δ(7)Li and low TDS in brackish groundwater, isotope fractionation may limit their use in recognizing salinity sources of groundwater with low TDS.
SN  - 0048-9697
UR  - http://www.ncbi.nlm.nih.gov/pubmed/30308862
UR  - http://dx.doi.org/10.1016/j.scitotenv.2018.09.122
N1  - PMID:30308862
ID  - Qi_etal2019
ER  -