posted on 2022-04-07, 15:41authored byYangzhi Liu, Yanlong Wang, Ting Wu, Jiang Xu, Daohui Lin
Nanoscale
zero-valent iron (nZVI) provides a promising solution
for organochlorine (OC)-contaminated soil remediation. However, the
interactions among nZVI, soil organic matter (SOM), and indigenous
dechlorinating bacteria are intricate, which may result in unascertained
effects on the reductive degradation of OCs and merits specific investigation.
Herein, we isolated an indigenous dehalogenation bacterium (Burkholderia ambifaria strain L3) from a paddy soil
and further investigated the biodechlorination of pentachlorophenol
(PCP) with individual and a combination of SOM and nZVI. In comparison
with individual-strain L3 treatment, the cotreatment with nZVI or
SOM increased the removal efficiency of PCP from 34.4 to 44.3–54.2%
after 15 day cultivation. More importantly, a synergistic effect of
SOM and nZVI was observed on the PCP removal by strain L3, and the
PCP removal efficiency reached up to 75.3–84.5%. Other than
the biodegradation through ortho- and meta-substitution under the
individual application of SOM or nZVI, PCP was further biodegraded
to 2,4,6-trichlorophenol (TCP) through para-substitution by the isolated
bacteria with the cotreatment of SOM and nZVI. The main roles of the
nZVI–SOM cotreatment in the biodegradation included the SOM-facilitated
microbial proliferation, the nZVI-promoted microbial transformation
of SOM, and the induced higher electron transport capacity of redox
Fe-PCP biocycling. These findings provide a novel insight into the
action of nZVI in environmental remediations.