Comparison of Zero Point of Charge Before and After Electricity Generation in Different Soil Textures

Three composite surface soil samples were collected and net surficial charges of the soil were estimated using potentiometric titration curves. Cells for electricity generation were prepared. The results of Potentiometric titration curves before electricity generation (EG) indicated that the pH for the zero point of charge (ZPC) was 5.9 in sandy loam soil, whereas for silty clay soil, the pH was 6.6; however, in silty clay loam, the ZPC settled at pH= 6.9. Relative changes in the soil properties were observed after EG occurred, as indicated by a decrease in soluble ions, except Na+; a decrease in soil pH, EC; and cation exchange capacity. It can be concluded that there is an increase in the potentiometric titration curve scattering and deviation after electricity generation (EG), which occurs in an alkaline medium after EG, and there is a similarity in the value of the zero point of titration before EG, which occurs in an acidic medium; in contrast, the pH value of ZPC after EG occurs in an alkaline medium. This study aimed to compare surface charge behaviors in the studied soils before and after electricity generation and specify both the zero point of charge and the zero point of titration.