Electrochemical removal of tannins from aqueous solutions

The applicability of electrochemical methods to remove tannins from wastewa ter was investigated. Gallotannic acid was used as the reference substance. Electrochemical experiments were performed using platinum electrodes. Macr oscale potentiostatic or galvanostatic electrolyses were carried out with s odium sulfate or sodium chloride as supporting electrolytes, to analyze dir ect and indirect oxidation processes. Operating variables such as pH and ch loride concentration were considered to determine their influence on the ef ficiency and energy consumption of the process. The simulation of a pilot p lant was carried out with a mathematical model, the parameters of which wer e determined by fitting of experimental profiles. The results of a prelimin ary investigation on the oxidation-coagulation process using sacrificial el ectrodes are also reported.