Fast Detection of Carbonate and Bicarbonate in Groundwater and Lake Water by Coupled Ion Selective Electrode

Abstract

Abstract The content of carbonate (HCO3−) and bicarbonate (CO32−) in the freshwater is an important characteristic of the geochemical environment. However, the environmental factors affect the concentration of two ions easily during the process of sampling, transportation and storage. It is a worldwide problem to determine the real content of carbonate and bicarbonate ions in the freshwater. To solve this problem, a new approach was proposed for the rapid determination of carbonate and bicarbonate ions in groundwater and lake water through a pH electrode combined with a CO2 electrode. The results showed that the liner range of bicarbonate was 0.027–570 mg L−1 and that of carbonate was 1.25 × 10−8−39.7 mg L−1. In the most case, the coexisting cation, anion and weak acid (K+, Na+, Mg2+, Cl−, SO42−