微波诱导过硫酸盐修复萘污染土壤的模拟优化

微波 (microwave，MW) 诱导过硫酸盐 (persulfate，PS) 去除土壤中的有机污染物是一种有效的土壤修复手段。以萘为土壤中典型的多环芳烃 (polycyclic aromatic hydrocarbons，PAHs) 有机污染物，利用COMSOL Multiphysics多物理场计算软件模拟，结合电磁耦合理论分析探索了微波电磁辐照过程中土壤有机物消解过程机制，并考察了PS浓度、MW辐照时间、MW温度、土壤含水率等工艺参数对萘去除效果的影响。结果表明，根据仿真优化后，微波反应器具有更好的加热均匀性。在微波谐振腔内，萘的降解过程符合伪一级反应动力学模型，MW诱导PS反应速率常数是常规电加热的1.6倍，这可能是因为极性过硫酸盐分子在微波交变电场的作用下胶体运动趋势增加；同时，多环芳烃有机物在微波场中的土壤传质性能得到优化，降低反应所需的活化能。当PS浓度为1.0 mol·L⁻¹、MW温度为80 ℃、土壤含水率为15%、MW处理时间为60 min时，萘的去除率最高可达到96.5%。本研究结果可为微波诱导过硫酸盐技术在多环芳烃污染土壤修复中的应用提供参考。

Simulation and optimization of naphthalene polluted soil remediation by microwave induced persulfate

PS (persulfate) induced by MW (microwave) has been proved as an effective strategy for organic polluted soil remediation. In this study, naphthalene was selected as the target soil contaminant, which was a typical kind of PAHs (polycyclic aromatic hydrocarbons). The mechanism of naphthalene removal during microwave electromagnetic irradiation process was explored by COMSOL Multiphysics software simulation together with the theoretical analysis of electromagnetic coupling. Moreover, the effects of PS concentration, MW irradiation time, MW temperature, and soil water content on naphthalene removal performance were investigated. The results indicated that the optimized microwave reactor based on software simulations revealed better heating uniformity. The degradation process of naphthalene conformed to the pseudo-first order kinetic model. Besides, the k value of PS induced by MW reaction were 1.6 times higher than those of conventional electrical heating. These results could be attributed to the polar PS molecules movement under the microwave alternating electric field, thereby optimizing the naphthalene mass transfer process in the soil and reducing the activation energy required for the reaction. The maximum naphthalene removal efficiency could reach 96.5% when the PS concentration, MW irradiation time, MW temperature, and soil water content was 1.0 mol L−1, 80 ℃, 60 min, and 15%, respectively. The results obtained from this study could provide theoretical support for practical applications of PS induced by MW to treat PAHs in soil.