Hydrogeochemical processes and suitability assessment of groundwater in the Jiaodong Peninsula, China

Groundwater is the primary source of water for domestic use and agricultural irrigation in Jiaodong Peninsula. This study collected 80 groundwater samples from Jiaodong Peninsula to characterize groundwater hydrogeochemical processes and the suitability of groundwater for domestic use and agricultural irrigation. The groundwater of Jiaodong Peninsula was categorized as slightly alkaline freshwater, with a Piper diagram classifying most samples as SO4·Cl-Ca·Mg and HCO3-Ca·Mg types. Major ions were Ca2+, Na+, SO42−, and HCO3−. The major processes driving the hydrochemistry of groundwater were identified as water-rock interactions as well as evaporation. The dissolution of silicate and cation exchange were the predominant hydrogeochemical processes responsible for groundwater chemistry. Four water samples showed seawater intrusion and some indicated pollution from anthropogenic activities such as industry, agriculture, and domestic sewage discharge. Overall, it was found that groundwater in most areas of Jiaodong Peninsula is suitable for domestic use and agricultural irrigation.