Effect of soil pH on thermally enhanced desorption of m-xylene by zero-valent iron particles under an electromagnetic field.
Effect of soil pH on thermally enhanced desorption of m-xylene by zero-valent iron particles under an electromagnetic field.
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DOI：
10.1016/j.jhazmat.2022.130019
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发表时间：
2022-09
影响因子：
13.6
通讯作者：
Kai Yu;Xiuqiong Yang;Mao Wan;Haowen Jiang;Penghui Shao;Liming Yang;Hui Shi;Xubiao Luo
中科院分区：
文献类型：
--
作者：
Kai Yu;Xiuqiong Yang;Mao Wan;Haowen Jiang;Penghui Shao;Liming Yang;Hui Shi;Xubiao Luo
本研究首次评价了一种利用零价铁(ZVI)在低频电磁场(EMF)下产生的热量从土壤中解吸污染物的新方法，并阐明了土壤pH对解吸过程的具体影响。结果表明，在外加电动势作用下，加入ZVI的土壤在20min内温度可达∼60℃，60min后土壤中间二甲苯残留量比未加入ZVI的土壤降低86.4%。间二甲苯的最有效解吸发生在pH为5的土壤中。解吸与ZVI颗粒的净加热能力有关，ZVI颗粒的净加热能力由表面腐蚀产物的pH依赖的形成来定义。金属铁的保存和Fe(II)物种的形成有利于生热。土壤pH还通过调节富里酸和ZVI的表面性质，影响间二甲苯的滞留和从ZVI到间二甲苯的局部导热。这项研究提供了关于pH对ZVI与EMF联用热解吸土壤污染物的影响的有价值的信息，并说明了该方法在修复受污染场地中的潜力。
This study, for the first time, evaluates a novel method for the desorption of contaminants from soil that uses the heat generated by zero-valent iron (ZVI) under low-frequency electromagnetic fields (EMF), and elucidates the specific effects of soil pH upon the process. It was found that the temperature of soil mixed with ZVI could reach up to ∼60 °C within 20 min under the applied EMF, and after 60 min the residual fraction of m-xylene in soil decreased by 86.4% compared to no-ZVI soil. The most efficient desorption of m-xylene occurred at a soil of pH 5. Desorption was related to the net heating capacity of the ZVI particles, which was defined by pH-dependent formation of surface corrosion products. The preservation of metal iron and formation of Fe(II) species was favored for heat generation. Soil pH also affected m-xylene retention and the local thermal conduction from ZVI to m-xylene by regulating the surface properties of fulvic acid and ZVI. This study provides valuable information regarding the impact of pH on the thermal desorption of soil contaminants by ZVI coupled with EMF and illustrates the potential of the method in the remediation of contaminated sites.