Polarographic logging PL

Several polarographic waves that correspond to current increasing at the potentials (Pi, (p2, cp, and (pii2o can be revealed on the cathodic polarogram (Fig. 2-49). The nature of these waves corresponds to the following electrochemical reactions. 

On anodic polarograms of chloride water (Fig. 2-50, curve 1), the Cl polarographic wave at the potential cpi corresponds to the reaction 2C1 — CLT + 2e , whilst on anodic 

The advantages of PL include real-time operation, increased reliability of analysis for volatile (O2) and unstable (Fe ) components, and high productivity. Its main applications are  

Hydrochemical investigations in deep boreholes and hydrochemical prospecting for ore deposits on the Karelian isthmus. Kola peninsula, and in northern Tajikistan have revealed very low concentrations of ore metals in groundwater. Usually, by means of the 

DCDL mode, it is possible to locate the anomalous concentrations of Fe and Mn . But only at low dissolved oxygen concentrations (as a rule, at depths of more than 300 m) is it possible to determine Zn, Ni and other heavy metals (Figs. 2-51, 2-52, 2-53). Use of the more sensitive PPL mode increases the effectiveness of hydrochemical prospecting for deep-seated ore deposits. 

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Fig. 2-53. Results obtained by polarographic logging (PL) at the Altyn-Topkan polymetallic deposit, northern Tajikistan (A) cathodic logging polarograms of the discrete mode of PL (B) distribution of manganese with depth obtained with the discrete mode of PL (C) distribution of manganese with depth obtained with the continuous mode of PL 1- ore interval (galena, sphalerite, pyrite) 2- potential of the polarographic waves (reproduced with permission from Klochkov et al., 1989).

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