BIOGEOCHEMICAL CHARACTERIZATION OF HOT SPRINGS (KUAN-TZU-LING, CHUNG-LUN AND BAO-LAI) IN SOUTHERN TAIWAN

Hot springs are important natural sources of the greenhouse gas to the hydrosphere and atmosphere. Kuan-Tzu-Ling (KTL), Chung-Lun (CL) and Bao-Lai (BL) are best-known hot springs in Taiwan. The importance of the hot spring is that when fluid erupted from an erupted point, some gases and muds also came out mixed with liquid. The samples were collected from different eruption points of Kuan-Tzu-Ling hot spring at KTL-1 point and KTL-2 during March 2009. Gases isolated from two eruption points (KTL-1 and KTL-2) were found significantly predominated in SO₂, H₂S, CH₄, and CO₂. In fluids of both eruption points, the ionic concentrations of Na⁺ and Cl^- were observed very high relative to other ions like K⁺, Mg²⁺, Ca₂ ²⁺, NO₂ ^-, and SO₄ ^2-, suggesting a marine origin from actively de-watering sedimentary pore waters along major structures on land. The elemental concentrations of KTL-1 and KTL-2 were estimated qualitatively and quantitatively using ICP-MS. The concentrations of V, Cr, Mn, Fe, Ni, and Zn, were found significantly higher in the sediment, whereas the concentrations of Cu, As, Se, Rb, Sr, and Ba were found significantly higher in the fluid than in the mud, which indicates that more electronegative elements were released into the fluid. The As concentration was found at the maximum in the fluid (>50µg/l) of KTL-1 in contrast to its sediment, which can signify the release of As under low redox conditions. However, the concentration of As indicates below detection level that indicates that some hot springs act as a As source and increase the As burden to the biotic environment. The humic acid was extracted from sediments of hot spring and then analyzed by Fourier Transform Infrared (FT-IR). The FTIR spectra showed the presence of possible functional group of secondary amines, ureas, urethanesm (amide) and silicon. Also, the results of present study also significantly reflected that the Kuan-Tzu-Ling hot spring contains sulfate-reducing bacteria that grew well in sulfate-reducing medium. In comparison with two other hot springs, the total dissolved solid, alkalinity, Na⁺, K⁺ and Cl^- are very high at Chung-Lun Hot spring. However, temperature is lower (>50 ^oC). The gases like SO₂, H₂S are higher at Kuan-Tzu-Ling and Chung-Lun than at Bao-Lai.