[Unit 7] Directions: Please fill in the blanks with the correct words.The energy consumption and current efficiency at different voltages were investigated and calculated based on the variation of voltage and current in the first 30 min. The curves for the current efficiency and energy consumption at different applied voltages are (1) in Figure 1. Both energy consumption and current efficiency (2) with voltage. When the applied voltage was 15 V, the energy consumption showed a (3) increase compared with that at a voltage of 10 V. (4) , the energy consumption (5) increased to 1.07W·h/g at a voltage of 20 V. Based on these results, and knowing that an overload voltage might lead to water electrolysis and scaling on the membrane surface, 15 V was determined to be the optimum voltage for the electrodialysis experiments.