State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
J Hazard Mater. 2010 Apr 15;176(1-3):213-9. doi: 10.1016/j.jhazmat.2009.11.015. Epub 2009 Nov 10.
A microwave assisted zero-valent iron oxidation process was studied in order to investigate the synergetic effects of MW irradiation on Fe/EDTA system (Fe/EDTA/MW) treated 4-nitrophenol (4-NP) from aqueous solution. The results indicated that the thermal effect of microwave improved the removal effect of 4-NP and TOC through raising the temperature of the system, as well as the non-thermal effect generated by the interaction between the microwave and the Fe resulting in an increase in the hydrophobic character of Fe surface. During the degradation of 4-NP in Fe/EDTA/MW system, the optimum value for MW power, Fe, EDTA dosage was 400 W, 2 g and 0.4 mM, respectively. The possible pathway for degrading the 4-NP was proposed based on GC/MS and HPLC analysis of the degradation intermediates. The concentration change course of the main bio-refractory by-products, the aminophenol formed in the degradation of 4-NP suggested a more efficient degradation and mineralization in Fe/EDTA/MW system. Finally, BOD(5)/COD(Cr) of the solution increased from 0.237 to 0.635 after reaction for 18 min, indicating that the biodegradability of wastewater was greatly improved by Fe/EDTA/MW system and would benefit to further treatment by biochemical methods.
采用微波辅助零价铁氧化法研究微波辐射对 Fe/EDTA 体系（Fe/EDTA/MW）处理水中 4-硝基苯酚（4-NP）的协同作用。结果表明，微波的热效应通过提高体系温度，增强了 Fe/EDTA 体系对 4-NP 和总有机碳（TOC）的去除效果，而微波与 Fe 相互作用产生的非热效应则增加了 Fe 表面的疏水性。在 Fe/EDTA/MW 体系中降解 4-NP 的过程中，微波功率、Fe 和 EDTA 用量的最佳值分别为 400 W、2 g 和 0.4 mM。根据降解中间产物的 GC/MS 和 HPLC 分析，提出了降解 4-NP 的可能途径。降解过程中主要难生物降解副产物氨基酚的浓度变化表明，Fe/EDTA/MW 体系对 4-NP 的降解和矿化更有效。最后，反应 18 min 后，溶液的 BOD5/COD（Cr）从 0.237 增加到 0.635，表明 Fe/EDTA/MW 体系大大提高了废水的可生物降解性，有利于进一步采用生化方法处理。
