电动修复过程中电压对土壤中芘降解及微生物群落的影响

Influence of voltage on pyrene removal and microbial community in soil during electrokinetic remediation

电动-微生物修复是一种新型的有机污染土壤修复技术。本文研究了修复过程中电压对土壤中芘降解及微生物群落的影响。结果表明,在不同电压梯度处理下,土壤中的芘降解与土壤微生物群落组成在阳极区和阴极区呈现不同的分布特征。阳极区芘降解与电压呈显著的正相关(r=0.55,P<0.01),在电压为2.0 V·cm-1时,阳极附近芘的降解率达到最高值(87.5%);阴极区芘的降解随着电压增大先升高后降低,电压为1.2 V·cm-1时阴极附近芘的降解率达到最高值(87.8%)。阳极区微生物活性和多样性与电压呈负相关;而阴极区微生物活性和多样性与芘降解的变化趋势相同。从芘的降解率和微生物群落结构来看,1.2 V·cm-1为本实验最合适的电压,该电压既保证了一定的电动氧化作用又促进了微生物发挥其最大的代谢降解能力。本研究为电动-微生物修复技术的调控提供了理论基础和技术方法。

Electrobioremediation is an innovative method to remedy organiccontaminated soil. This paper studied the effect of voltage on pyrene degradation and microbial community in soil during remediation process. The results showed that pyrene degradation and microbial community composition were different at the anode and cathode regions with the change of voltage. There was a positive correlation between voltage and pyrene degradation （r=0.55, P〈0.01） at the anode region, and the highest percentage of pyrene degradation reached 87.5% under the treatment of 2.0 V·cm^-1 at anode region. Meanwhile, with the increase of voltage, the pyrene degradation rate increased at first and then decreased at the cathode region, and the highest percentage of pyrene degradation reached 87.8% under the treatment of 1.2 V·cm^-1 at the cathode region. A negative relationship existed between microbial activity and diversity and voltage at the anode region, while the microbial activity and diversity showed the same trend as the pyrene degradation at the cathode region. According to the results of pyrene degradation and microbial community, 1.2 V·cm^-1 was the most suitable voltage, which ensured the electric oxidation and maximized the role of microbial degradation. Our study provided the theoretical foundation and technical method for the control of electrobioremediation process.