Electrochemical removal of sodium ion from fermented food composts

Fermented food composts, to be recycled into fertilizer and animal feed, re quire sodium chloride concentrations to be less than 1 wt% due to several t oxicities. Electrochemical methods are used to remove sodium ions from ferm ented food composts. By washing the compost with tap water (with no electri c current applied), 48% of the initial sodium ion is removed. With an elect ric current density of 3 mA/cm(2) (the distance between the electrodes is 1 6 cm), the removal efficiency increases to 96% for a 36 h operation. Major factors influencing the efficiency are the treatment time and the electric current density. Removal efficiency increases with energy demand to yield 9 6% removal at 60 Kwh/m(3). Due to the difference in relative ionic mobility , less than 9% of calcium is removed, during the same operation time, which supports the feasibility of this method.