Concentration optimization of sodium percarbonate as buffering catholyte on stacked microbial desalination cell by utilizing tofu wastewater as a substrate

The objective of this research is to obtain the optimum concentration of Sodium percarbonate (SP) as catholyte which gives the best desalination performance in Stacked Microbial Desalination Cell (SMDC) system using tofu wastewater as a substrate. SMDC is a promising technology for wastewater treatment and water desalination to overcome the problem of water crisis and the use of Sodium percarbonate will prevent pH imbalance which is one of the major issues in SMDC technology. Four Sodium percarbonate concentration variations of 0.05, 0.1, 0.15 and 0.2M were examined at 50 hours operating time. The optimum performance of Sodium percarbonate is then compared with other commercial catholyte Potassium permanganate. The result of this research is the optimum concentration of sodium percarbonate as a catholyte is at concentration equal to 0.15 M with 1.77% salt removal in Desalination-Cathode Chamber and 0.82% salt removal in Desalination-Anode Chamber. Also, the best catholyte is SP in comparison to KMnO₄ because it acts as a better electron acceptor (oxidation agent) as well as buffering catholyte with higher value of SDR and TDR equal to 1.2469 g/(L.h) and 1.8704 g/h respectively.