Investigation on the Hydrogeochemical Characteristics and Controlling Mechanisms of Groundwater in the Coastal Aquifer

Groundwater contamination in coastal areas has attracted widespread attention. However, studies on the hydrogeochemical characteristics and controlling mechanisms aquifers are still lacking. In this study, 71 sets of groundwater samples were collected during dry wet seasons a city, Shandong Province. Correlation principal component analyses used to identify pollution sources. Meanwhile, Piper diagrams, Gibbs plots, ion ratios, saturation indices employed investigate mechanisms. The results revealed that components included Na+, NH4+, Cl−, SO42−, NO3−, NO2−, Pb, As, Se, TDS, TH, F−, Mn. Pollution compositions study area primarily derived from natural processes anthropogenic activities. nitrogen resulted agricultural exceedance SO42− was mainly due leaching waste by rainfall. High F− related sea intrusion. Pb Se might have been caused As inputs factors. poor seepage conditions anoxic promoted enrichment concentration most season larger than season. There no significant differences water chemistry type chemical dominated dissolution halite, gypsum, anhydrite, as well cation exchange reaction. influence seawater intrusion not serious.