Geobacter lovleyi가 nZVI의 TCE 분해 속도, 반응경로 및 부산물에 미치는 영향

Abstract

Nano-scale zero valent iron (nZVI) is known as an effective material for the removal of chlorinated hydrocarbons. It has been widely researched considering the microorganism and geological conditions. This study investigated the effect of Geobacter lovleyi on TCE dechlorination rates, pathways and byproducts by nZVI. Batch experiments showed that rate constants (kobs) by the nZVI reaction increased from 0.3 day-1 to 0.49 day-1 by the injection of G. lovleyi. In contrast, ethene production decreased from 0.03 mM to 0.02 mM. Most TCE was dechlorinated via β-elimination producing acetylene by nZVI, whereas G. lovleyi produced cis-DCE as the major product via hydrogenolysis reaction. The degradation behaviour of TCE and cis-DCE by nZVI was measured to compare the difference in ethene production between hydrogenolysis and reductive β-elimination reactions. As a result, 0.13 mM acetylene and 0.03 mM ethene were generated by nZVI TCE dechlorination after 7 days. However, in the case of starting from cis-DCE 0.04 mM acetylene, 0.01 mM ethene was created. These results suggest that the production of acetylene was promoted by nZVI and incresed ethen. Therefore, microorganism and environmental conditions should be considered for the effective application of nZVI.