Photovoltaic Powered Electrokinetic Restoration of Saline Soil

Abstract

Electrokinetic techniques are currently being explored as a means of extracting or removing contaminants from soils, sediments, and sludge. However, energy costs account for 25% of total operation costs. In this study, we investigated the efficiency of conventional electrokinetic and photovoltaic powered electrokinetic systems for the removal of salts from saline agricultural soils. We tested four different potentiostatic systems: a solar-powered system (S1), a solar-powered system with battery backup charged by solar panels during the daytime (S2), a conventional direct current (DC) system with power-on during the daytime and power-off after sunset (S3), and a normal conventional DC system (S4). There were no major differences with regard to how effectively the different systems extracted chlorides and nitrates. System S2 extracted the greatest quantity of soil electrical conductivity (EC) and other salts, while system S1 extracted the least. The photovoltaic powered electrokinetic system provided a limited amount of electrical energy because the system could not generate electricity at night. However, we believe that a photovoltaic system that combines solar panels with rechargeable batteries is an excellent alternative to conventional power supply systems in terms of energy cost in electrokinetic restoration.

Keywords:

• desalination
• energy cost
• salt
• solar power

ACKNOWLEDGEMENTS

This work was supported by the Korea Electrotechnology Research Institute (KERI).