3.2. Effect of additional electrolyte on ECH Process
To enhance the reaction rate generally salt addition is beneficial during the electrochemical process. NaCl is generally used as supporting electrolyte in electrochemical processes. The investigation of the effect of electrolyte concentration was performed in the range 0–6 g L1 for NaCl. NaCl was chosen as supporting electrolyte due to its capability to enhance the microalgal recovery efficiency and shortened the reaction times [20]. It is observed that increasing the electrolyte concentration may increases the microalgal recovery efficiency due to the increased mass transport of ions to
the anode surface. The Fig. 3 represents the effect of NaCl concentration on the microalgal recovery efficiency of C. sorokiniana microalgae during ECH process carried out at 1 Ampere. We observed that the addition of electrolyte in microalgal broth increased the microalgal recovery efficiency considerably. Addition of 2 g L1 NaCl, 4 g L1 NaCl and 6 g L1 NaCl the achieved microalgal recovery efficiencies of 68%, 92% and 95% respectively, compared to only 66% without the addition of NaCl. It seems that increasing the NaCl concentration as electrolyte in microalgal broth may increases the
microalgal recovery efficiency due to the increased mass transport of ions. Addition of electrolyte is also beneficial in terms of cost because it reduced the power consumption of the ECH process (1.6 kWh kg-1 ) (Table 1 ).