Comparison of hydroxyl radicals generation during granular activated carbon regeneration in DBD reactor driven by bipolar pulse power and alternating current power

Hydroxyl radicals (center dot OH) is a kind of critical active species produced in the process of discharge plasma. We employed an innovative method to explore the center dot OH generation features during granular activated carbon (GAC) regeneration in a DBD reactor, which was driven by a bipolar pulse power and an alternating current (AC) power, respectively. This measure was used the salicylic acid (SA) as a center dot OH scavenger, which was adsorbed on GAC. And then the amount of center dot OH was determined by the SA extracts from GAC using HPLC. The influence of the reactor supplied power on center dot OH generation was assessed respectively powered by bipolar pulse and AC power. Besides, the effects of applied voltage, air flow rate, and GAC water content on center dot OH formation were also evaluated under the two powers. Results showed that the greater discharge strength and air support were in favor of higher center dot OH generation, and an optimal value of 20% for GAC water content was also observed. Moreover, the center dot OH formation and its energy efficiency supplied by bipolar pulse power were both superior than AC power. Correspondingly, the phenol degradation on GAC and GAC regeneration motivated by bipolar pulse power were also enhanced than AC power. (C) 2017 Elsevier Ltd. All rights reserved.

羟基自由基（·OH）是放电等离子体过程中产生的一种关键活性物质。我们采用一种创新方法，分别在双极性脉冲电源和交流（AC）电源驱动的介质阻挡放电（DBD）反应器中，探究颗粒活性炭（GAC）再生过程中·OH的产生特性。该方法以水杨酸（SA）作为·OH的清除剂，将其吸附在GAC上，然后通过高效液相色谱（HPLC）测定从GAC中提取的SA来确定·OH的量。分别评估了双极性脉冲电源和交流电源供电时反应器电源对·OH产生的影响。此外，还在两种电源下评估了施加电压、空气流速和GAC含水量对·OH形成的影响。结果表明，较大的放电强度和空气支持有利于产生更多的·OH，并且观察到GAC含水量的最佳值为20%。此外，双极性脉冲电源产生·OH及其能量效率均优于交流电源。相应地，双极性脉冲电源驱动下GAC上苯酚的降解以及GAC的再生效果也优于交流电源。（C）2017爱思唯尔有限公司。保留所有权利。