| 内容提要: |
A novel permeable electroactive well (CPEW) was constructed in this study.The mass removalof BaP was 52.52% in the CPEW and 44.94% in the OPEW. Of the removed BaP from the soil, a very low portion of BaP were stored in sample Sin and water. The BaP was removed from the soil mainly via physically adsorption by porous anode and microbial degradation, which accounted 66.31% and 33.51% of the removed BaP in the CPEW, 86.26% and 13.57% in the OPEW. The bioelectrochemical process greatly enhanced the mass degradation of BaP from 6.13% (OPEW) to 17.63% (CPEW). The porous graphite felt contributed mostly to BaP removal including enrichment/adsorption as a filtration layer and bioelectrochemical degradation as an anode. The higher abundances of Gammaproteobacteria and Clostridia could transfer electron, which might contributed to the improvement of BaP degradation. Based on the function predication analysis, we deduce the bioelectrochemical process enhance the BaP degradation efficiency were very likely through increasing the degradation rate without changing the metabolic pathway. The constructed CPEW could be applied in the in situ remediation of soil or groundwater contaminated with refractory organics.
The degradation products of BaP were detected in different sample sites (Anode, S0-1 cm, S1-6 cm and S6-11 cm) in CPEW. It showed that the species of the biodegradation products of BaP varied with the distance of samples from the anode. Bioelectrochemical process occurred on the filtration anode upregulated five major metabolic pathways, including glycolysis or gluconeogenesis, oxidative phosphorylation, citrate cycle (TCA cycle), pyruvate metabolism and nitrogen metabolism. |