Environmental Biogeology of Aquatic Ecosystem:In the Case of the Rivers in Kanazawa

Water temperature, pH and NO2-N concentration increased from upstream to downstream whereas Eh decreased contrastly. DO, NH4-N, PO4-N and EVAS changed largely during two years.

Besides the effects of human daily life drainage from the residence areas, the geological environments, underground water and microorganisms had a considerable impact on the quality of river water. Rapidexploitation of soils caused the oxidation of underground water from Omma formations which contained high concentrations of Mn, Fe, Ca and K ions, resulting in a larg edevelopment of microbial mat. Smectite gradually decreased with the increasing ofkaolin minerals from upstream to downstream, suggesting that these clay minerals could have reacted with drainage water by cations exchange and affected partially the pH of river water.Contributions of bacteria and clay minerals in the remediation of polluted riverwater have been proved through this study.