生物电化学系统硝基酚降解与其结构关系研究

Study on Relationship between Nitrophenol Degradation and its Structure in Bioelectrochemical System

实验构建了有隔膜的生物电化学系统(BES)系统,考察一硝基酚的3种同分异构体,邻硝基酚(ONP)、间硝基酚(MNP)和对硝基酚(PNP)的降解与其结构的关系。分析了在不同阴极电位和水力停留时间下的降解情况,比较了硝基酚的电子云密度、前线轨道能量和氢键角度。结果表明,同等阴极电位和阴极水力停留时间下3种物质的降解程度不同,但降解顺序呈现出统一的趋势,即ONP最容易发生降解,PNP最难。得电子能力最强的是ONP,最弱的是PNP。PNP的最高已占轨道能量最低,能极差最大,说明PNP所受束缚最大,轨道最难发生变化;而ONP的能级差最小。这都说明了硝基酚的降解顺序为ONP>MNP>PNP。

A septate bioelectrochemical system(BES) was constructed to investigate the relationship between the degradation of three isomers of mononitrophenol, o-nitrophenol(ONP), m-nitrophenol(MNP) and p-nitrophenol(PNP) and their structures. The degradation of nitrophenol at different cathodic potential and hydraulic retention time was analyzed. The electron cloud density, frontier orbital energy and hydrogen bond angle of nitrophenol were compared. The results showed that the degradation degree of three substances was different under the same cathodic potential and cathodic hydraulic retention time, but the degradation order showed a unified trend, that is, ONP was the most easily degraded and PNP was the most difficult. The most powerful electron was ONP, the weakest was PNP. The highest PNP accounts for the lowest orbital energy and the largest energy range, which indicated that PNP was most bound and the orbital was the most difficult to change, while ONP had the lowest energy level difference. This indicated that the order of degradation of nitrophenol was ONP >MNP >PNP.