Hua Tingyu, Li Shanshan, Hu Jingli, Yan Wei
Key Laboratory of Solid Waste Recycling and Resource Recovery, Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an, China.
Front Chem. 2024 Aug 16;12:1450233. doi: 10.3389/fchem.2024.1450233. eCollection 2024.
The extensive use of methyl -butyl ether (MTBE) as a gasoline additive has caused serious environmental problems that need to be addressed urgently. The feasibility of remediation of MTBE-contaminated groundwater by ZSM-5 zeolite with SiO/AlO ratio of 50/130/360 was explored. The SiO/AlO ratio had a great influence on the physicochemical properties and structure, as well as the adsorption and mass transfer of MTBE on ZSM-5. The adsorption of MTBE on zeolites with SiO/AlO ratios of 50 and 130/360 followed the Langmuir and Freundlich models, respectively, and was controlled by different mass transfer processes. The morphology and adsorption capacity of ZSM-5 (50) and ZSM-5 (130) differed significantly, while the differences between ZSM5-(130) and ZSM-5 (360) were less pronounced. ZSM-5 (360) had higher adsorption capacity and adsorption efficiency for MTBE, and the larger BET surface area, pore volume and stronger hydrophobicity were the key factors to promote MTBE adsorption. Compared to activated carbon (AC), ZSM-5 (360) was more effective for MTBE removal at low concentrations (≤200 mg·L) and had the advantage of selective adsorption of MTBE with the addition of BTEX. In column adsorption, decreasing the concentration had opposite effects on MTBE removal by ZSM-5 and AC. At 5-10 mg·L, ZSM-5 (360) column reduced effluent concentration and improved bed utilization and removal efficiency.
甲基叔丁基醚（MTBE）作为汽油添加剂的广泛使用已引发严重的环境问题，亟待解决。本文探究了硅铝比为50/130/360的ZSM-5沸石修复MTBE污染地下水的可行性。硅铝比对ZSM-5的物理化学性质、结构以及MTBE在其上的吸附和传质过程有很大影响。MTBE在硅铝比为50和130/360的沸石上的吸附分别遵循朗缪尔模型和弗伦德里希模型，且受不同传质过程控制。ZSM-5（50）和ZSM-5（130）的形貌和吸附容量差异显著，而ZSM-5（130）和ZSM-5（360）之间的差异则不太明显。ZSM-5（360）对MTBE具有更高的吸附容量和吸附效率，更大的BET比表面积、孔容以及更强的疏水性是促进MTBE吸附的关键因素。与活性炭（AC）相比，ZSM-5（360）在低浓度（≤200 mg·L）下对MTBE的去除效果更佳，且在添加苯系物的情况下具有选择性吸附MTBE的优势。在柱吸附中，降低浓度对ZSM-5和AC去除MTBE的影响相反。在5 - 10 mg·L时，ZSM-5（360）柱降低了流出物浓度，提高了床层利用率和去除效率。
