College of Chemical Engineering and Materials Science, Tianjin University of Science & Technology, No. 29 13th Avenue, Economic and Technologic Development Zone, Tianjin, 300457, PR China.
Chemosphere. 2020 Dec;260:127588. doi: 10.1016/j.chemosphere.2020.127588. Epub 2020 Jul 9.
A series of CX-TiO(Carbon Xerogel- TiO) composites with a hierarchical porous structure were obtained through the sol-gel method followed by drying and carbonization, and have been applied to treating solubilizing wastewater containing a high concentration of phenanthrene (PHE). The characterizations demonstrated that the CX-TiO exhibits a hierarchical porous structure, with particles of carbon and P25 being uniformly in the matrix. Removal efficiency of CX-TiO on PHE in soil washing eluent (SWE) were evaluated under ultraviolet (UV) irradiation or dark condition, and P25 was employed as the reference. The results revealed that CX-TiO(0.2) had the best removal effect on PHE, with the efficiency as high as 97.8% under UV illumination within 15 h. It demonstrated that in the process of PHE removal by CX-TiO whether it was under UV illumination or not, the adsorption plays a dominant role in the early stage. The kinetic behavior of PHE adsorption was fitted using the pseudo-first-order and pseudo-second-order, and Langmuir model and Freundlich models were applied to describe the PHE adsorption isotherms. The results indicating that it was a chemical adsorption process, which was influenced by the interaction between PHE and CX-TiO, and PHE is adsorbed on the interface of CX-TiO(0.2) in a single layer form, instead of agglomerating in the admicelle. A possible mechanism of removal of solubilized PHE in SWE was speculated, in which both hierarchical porous structure and appropriate micropores size of CX-TiO were indispensable to the selective adsorption and degradation of PHE. Recycling performance certificated that the selective removal efficiency of PHE could still reach 82.09% after five recycles. Thus the excellent performance testified that the CX-TiO have great potential in treating SWE containing solubilized PAHs.
一系列具有分级多孔结构的 CX-TiO（碳气凝胶- TiO）复合材料是通过溶胶-凝胶法制备的，然后经过干燥和碳化处理，已应用于处理含有高浓度菲（PHE）的溶解废水。表征结果表明，CX-TiO 具有分级多孔结构，碳颗粒和 P25 均匀地存在于基质中。在紫外（UV）照射或黑暗条件下，评价了 CX-TiO 在土壤洗涤洗脱液（SWE）中对 PHE 的去除效率，并以 P25 作为参比。结果表明，在 15 h 内，在 UV 照射下，CX-TiO（0.2）对 PHE 的去除效果最好，去除效率高达 97.8%。结果表明，在 CX-TiO 去除 PHE 的过程中，无论是否有 UV 照射，吸附在早期阶段都起着主导作用。采用拟一级和拟二级动力学模型对 PHE 吸附动力学行为进行拟合，Langmuir 模型和 Freundlich 模型分别用于描述 PHE 吸附等温线。结果表明，这是一个化学吸附过程，受 PHE 和 CX-TiO 之间相互作用的影响，PHE 以单层形式吸附在 CX-TiO（0.2）的界面上，而不是在胶束中聚集。推测了 SWE 中溶解 PHE 的去除可能机制，其中 CX-TiO 的分级多孔结构和适当的微孔尺寸对于 PHE 的选择性吸附和降解都是必不可少的。回收性能证明，经过五次循环后，PHE 的选择性去除效率仍可达到 82.09%。因此，卓越的性能证明了 CX-TiO 在处理含有溶解态多环芳烃的 SWE 方面具有巨大的潜力。
