脉冲电吸附技术深度脱氮及分子动力学模拟

针对城市污水处理厂二级出水的氮素指标达不到国家一级A排放标准的问题，采用脉冲开关电源代替了传统电吸附中的直流稳压电源，用活性炭粉末为吸附材料制备电极板，构建了脉冲电吸附反应装置.以NO₃^--N和NH₃-N的去除率为判据，比较了脉冲电吸附法和直流电吸附法在去除模拟废水中氮素的差异，结果表明，60min内，脉冲电吸附法有更高的去除效率，且在脉冲电场占空比50%、频率10⁴Hz的条件下，氮素的去除率最高.利用分子动力学模拟分析得知，在脉冲电场下，水分子中氢、氧原子的取向更随机，相比于直流电场，水分子偶极矩的取向极化作用被弱化，减小了离子的传质阻力，从而提高离子迁移效率.

Capacitive deionization using a pulsed power supply for depth denitrogenation and molecular dynamics simulation

A pulsed power supply was used in capacitive deionization instead of DC power supply. A pulsed capacitive deionization cell was constructed. The removal rates of NO₃^--N and NH₃-N by pulsed-CDI and DC-CDI were compared, and within 60 minutes, a higher removal efficiency by pulsed-CDI. The removal rate of NO₃-N was the highest under 50% duty cycle and 10⁴Hz frequency. Results from molecular dynamics simulation showed that the orientation of hydrogen and oxygen atoms in water molecules was more random under pulsed electric field. Compared with DC electric field, the orientation polarization of water molecules' dipole moment was weakened and the mass transfer resistance of ions is reduced.