Environmental Contamination Realities and Geochemical Characteristics for Groundwater in Kwangju City

The objective of this study is to investigate the environmental contamination realities and geochemical characteristics of groundwaters. Fifty two groundwater samples were collected and analyzed out of the urban, suburb and industrial areas in Kwangju city. The pH, Eh, EC (electric conductivity), TDS (total dissolved solid), DO (dissolved oxygen), ER (electric resistivity) and NaCI percentage were measured in the field and, ration elements such as K, Na, Mg, Si, Ca, Fe, Sr, Al, Cr, Mn, Cu, Zn, As, Cd, Hg, Pb, Se, Ge, Th and U were analyzed by GFAAS, AAS, ICP-AES and ICP-MS. Anions, F, Cl^-, Br^-, NO₃^- and SO₄^(2-) were analyzed by IC and the HCO₃^- contents are determined by titration with Phenolphthalein and Methyl red-brom cresol green. TDS vs Mg, Na, Ca, Cl^-, HCO₃^-, SO₄^(2-), U, hardness values were clearly related each other. At the urban site, the Eh, EC, TDS, Mg, Na, Ca, Cl^- and SO₄^(2-) values were higher and NO₃^-, Cr, Pb and Zn values were highist in the industrial groundwater. Most groundwater showed a calcium-bicarbonate-chloride dominating water quality type. On stability diagrams, Kwangju groundwater is included in the kaolinite stable area.