School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China E-mail:
College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China.
Water Sci Technol. 2020 May;81(10):2066-2077. doi: 10.2166/wst.2020.262.
Selective removal of petroleum hydrocarbons (PHCs) from soil washing effluents is the key to the surfactant-enhanced soil washing technology. In this study, the diatomite was modified by nonionic surfactant TX-100 and applied in the selective adsorption of PHCs in the soil washing effluents. The modified diatomites were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, N adsorption/desorption and X-ray photoelectron spectroscopy respectively. The adsorption process followed the pseudo-second-order model and the adsorption isotherms indicated that the interaction between PHCs and modified diatomite was monolayer adsorption. The important operating factors such as TX-100 dosage, adsorbent dosage, time and temperature were optimized. With the participation of the low-cost adsorbent TX3-Db with high adsorption capacity, the recovery efficiency of the washing effluents was still up to 78.9% after three cycles. A selective adsorption mechanism, based on steric hindrance and electrostatic repulsion, was proposed to explain the removal of PHCs from washing effluents.
从土壤洗涤废水中选择性去除石油烃（PHCs）是表面活性剂强化土壤洗涤技术的关键。本研究采用非离子表面活性剂 TX-100 对硅藻土进行改性，并将其应用于土壤洗涤废水中 PHCs 的选择性吸附。通过扫描电子显微镜、傅里叶变换红外光谱、X 射线衍射、N 吸附/脱附和 X 射线光电子能谱分别对改性硅藻土进行了表征。吸附过程符合拟二级动力学模型，吸附等温线表明 PHCs 与改性硅藻土之间的相互作用为单层吸附。优化了 TX-100 用量、吸附剂用量、时间和温度等重要操作因素。在低吸附容量但成本低廉的 TX3-Db 吸附剂的参与下，三次循环后洗涤废水中的回收效率仍高达 78.9%。提出了一种基于空间位阻和静电排斥的选择性吸附机理，解释了从洗涤废水中去除 PHCs 的机制。
