MEASUREMENT OF WATER QUALITY OF TIDAL FLAT UPWELLING WATER BY ELECTRODE REACTION

Abstract

 The Platinum electrode (PtE) measures potential in seawater, indicating the oxidation-reduction potential (ORP). When reductant (Red) is introduced around the electrode, the electrode potential decreases. Because dissolved oxygen (DO) is consumed in the oxidation of Red, forming an anoxic state in the water column. Continuous measurement of the electrode potential enables us to understand the introduction of Red and the process of anoxia in the benthic habitat. In addition, the potential of the carbon electrode (CfbE) responds to the activity of attached organisms, making it possible to evaluate the biological habitat. This study aimed to link the potential changes of PtE and CfbE with the physical and biological phenomenon in the water of intertidal flats. The changes in potential, DO, salinity, and temperature were measured using electrode and water quality measurement devices near the seawall. The change of potential in PtE was mainly dominated by tide changes in the intertidal flat. While that in CfbE was linked with biofilm formation, indicating the condition of the benthic habitat. Therefore, changes of potential in PtE and CfbE can be used to clarify the ecosystem state of intertidal flats.