Huang Xinhong, Liang Yan, Yun Jinhu, Cao Feishu, Xie Tian, Song Hainong, Wang Shuangfei
School of Resources, Environment and Materials, Guangxi University Nanning 530004 China
Key Laboratory of Environmental Protection (Guangxi University), Education Department of Guangxi Zhuang Autonomous Region Nanning 530004 Guangxi China.
RSC Adv. 2024 Jan 18;14(5):3033-3043. doi: 10.1039/d3ra06568e. eCollection 2024 Jan 17.
1,2-Dichloroethane (1,2-DCA) is a typical organic chlorinated compound largely utilized in chemical manufacturing and industrial production and also a common pollutant in organically contaminated sites. The adsorption of 1,2-DCA on soil grains significantly influences its environmental fate and removal process. This study investigated the influence of fulvic acid (FA) and humic acid (HA) on the adsorption-desorption of 1,2-DCA in solid-liquid interfaces in water or constructed porous media. Experimental findings demonstrated the influence of organic matter on the adsorption of 1,2-DCA at the solid-water interface. 1,2-DCA adsorption increased in the FA or HA-treated soils when organic matter was present on the solid surfaces. The 1,2-DCA adsorption in the mixture of FA and HA was slightly lower than that in single organic acids, depending on the binding of FA and HA to the soil grains/colloids. Basic conditions reduced the adsorption of 1,2-DCA on soils, whereas acidic conditions enhanced adsorption due to the increased interactions adsorption sites and hydrogen bonds. Conversely, the presence of organic matter in solutions (liquid phase in constructed porous media) will reduce the adsorption of 1,2-DCA on solid surfaces and increase the transport in the model aquifer. The combination of FA, HA, and rhamnolipids is helpful for the removal of 1,2-DCA from solid surfaces. Additionally, because of the enhanced desorption, the risk of 1,2-DCA contamination in groundwater can be increased when the organic matter or surfactant is present in the liquid phase if the eluent is not collected. This study helps to better understand the cooperative interaction of soil organic matter and chlorinated hydrocarbons at solid-water interfaces and the environmental fate and potential removal strategies of chlorinated hydrocarbons in contaminated sites.
1,2 - 二氯乙烷（1,2 - DCA）是一种典型的有机氯化合物，在化学制造和工业生产中大量使用，也是有机污染场地中的常见污染物。1,2 - DCA在土壤颗粒上的吸附显著影响其环境归宿和去除过程。本研究调查了富里酸（FA）和腐殖酸（HA）对水或构建的多孔介质中固 - 液界面上1,2 - DCA吸附 - 解吸的影响。实验结果证明了有机物对固 - 水界面上1,2 - DCA吸附的影响。当固体表面存在有机物时，FA或HA处理过的土壤中1,2 - DCA的吸附增加。FA和HA混合物中1,2 - DCA的吸附略低于单一有机酸中的吸附，这取决于FA和HA与土壤颗粒/胶体的结合情况。碱性条件降低了1,2 - DCA在土壤上的吸附，而酸性条件由于吸附位点和氢键相互作用增加而增强了吸附。相反，溶液（构建的多孔介质中的液相）中有机物的存在会降低1,2 - DCA在固体表面的吸附并增加其在模型含水层中的迁移。FA、HA和鼠李糖脂的组合有助于从固体表面去除1,2 - DCA。此外，由于解吸增强，如果不收集洗脱液，当液相中存在有机物或表面活性剂时，地下水中1,2 - DCA污染的风险可能会增加。本研究有助于更好地理解土壤有机物与氯代烃在固 - 水界面的协同相互作用以及污染场地中氯代烃的环境归宿和潜在去除策略。
