Abstract:
The hydrochemical of groundwater in the Holocene, Pleistocene, elurium and bedrock fissures in Putian plain was analyzed. The results show that, hydrochemical types of phreatic water are HCO
3-Ca, HCO
3·Cl-Na·Ca, Cl·HCO
3-Na·Ca, Cl-Na, from the mountain to the sea. There are four features:(1)HCO
3- and Ca
2+are remarkable, it is newly formed, with transient material exchange by the surrounding rock minerals, after the subsurface infiltration,(2)Cl
- and Na
+ are remarkable, it is sealed ancient seawater,(3)Cl
- and Ca
2+ are remarkable, Na
+ of the groundwater is exchanged with Ca
2+ of the minerals in the surrounding rocks,(4)owing to the CO
2 dissolved in water, during the precipitation, the HCO
3- proportion of the groundwater anion is raised, but the cation composition have stayed the same. Two desalination processes have been found in this article. The first is desalination processes with cation exchange. The second is CO
2 dissolved during leaching.