Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Department of Environmental Health Engineering, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Department of Environmental Health Engineering, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
J Hazard Mater. 2019 Nov 5;379:120839. doi: 10.1016/j.jhazmat.2019.120839. Epub 2019 Jun 27.
This work aimed to investigate the performance of biosurfactant, produced by a halotolerant bacterial strain, Pseudomonas aeruginosa PF2, for desorption of PAHs from soil, followed by electrokinetic oxidation of the desorbed solution using Magnetite Nanoparticles Modified Graphite (MNMG). Pyrene (PYR), anthracene (ANT) and phenanthrene (PHE) were used as contamination model. Produced and extracted biosurfactant was characterized as rhamnolipid with Critical Micelle Concentration (CMC) of 60 mg/L and emulsification index (E) value of 60.2% for n-hexadecane, 58.4% for n-heptane and 55.6% for n-Hexane, respectively. Results of LC-MS/MS analysis indicated the presence of seven major peaks at m/z of 677.5, 531.1, 649.3, 528.9, 475.1, 359 and 503.2, which corresponded to the deprotonated molecules of RhaRhaCC RhaCC RhaRhaCC, RhaCC RhaCC Rha-C: and RhaCC respectively. The maximum desorption of PAHs was derived at pH value of 6, CMC of 3 and contact time of 24 h. Modification of graphite electrode enhanced the PAH degradation significantly. In electrokinetic oxidation of desorbed solution, the best results were observed at pH value of 5, contact time of 6 h, voltage of 3 V and electrolyte concentration of 25 mg/L, with the average removal efficiency of higher than 99% for all studied PAHs.
本研究旨在探究耐盐菌 Pseudomonas aeruginosa PF2 所产生物表面活性剂在解吸土壤中多环芳烃（PAHs）方面的性能，随后利用磁铁矿纳米颗粒修饰石墨（MNMG）对解吸液进行电动氧化。选用芘（PYR）、蒽（ANT）和菲（PHE）作为污染模型。所产生物表面活性剂被鉴定为鼠李糖脂，其临界胶束浓度（CMC）为 60mg/L，对正十六烷、正庚烷和正己烷的乳化指数（E）值分别为 60.2%、58.4%和 55.6%。LC-MS/MS 分析结果表明，存在七个主要峰，其质荷比（m/z）分别为 677.5、531.1、649.3、528.9、475.1、359 和 503.2，分别对应 RhaRhaCC RhaCC RhaRhaCC、RhaCC RhaCC Rha-C：和 RhaCC 的去质子分子。在 pH 值为 6、CMC 值为 3 和接触时间为 24h 时，PAHs 的最大解吸量得以实现。石墨电极的修饰显著增强了 PAH 的降解效果。在解吸液的电动氧化中，在 pH 值为 5、接触时间为 6h、电压为 3V 和电解质浓度为 25mg/L 时，观察到最佳效果，所有研究的 PAHs 的平均去除效率均高于 99%。
