Reductive dechlorination of trichloroethylene by polyvinylpyrrolidone stabilized nanoscale zerovalent iron particles with Ni

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>We developed a novel stabilized nanoscale zerovalent iron (NZVI) particles with Ni using an electron conducting polymer, polyvinylpyrrolidone (PVP), to selectively dechlorinate trichloroethylene (TCE) to non-toxic intermediates. The size of the PVP stabilized NZVI-Ni ((PVP-NZVI-Ni), average diameter: ∼20nm) is smaller than that of bare NZVI (50–80nm) due to the prevention of agglomeration of the resultant iron particles by PVP. PVP-NZVI-Ni showed a complete removal of TCE in 1h with superior dechlorination kinetics (<I>k<SUB>obs</SUB> </I> =5.702h<SUP>−1</SUP>) and ethane selectivity (98%), while NZVI-Ni showed 5 times slower dechlorination kinetics (1.218h<SUP>−1</SUP>). Other PVP-NZVI-metals (i.e., Cu, Sn, Co, and Mn) also enhanced the TCE dechlorination, but they were much slower (<I>k<SUB>obs</SUB> </I> =0.024−0.411h<SUP>−1</SUP>) than that of PVP-NZVI-Ni. In column test, PVP-NZVI-Ni exhibited better mobility (95% of PVP-NZVI-Ni recovery in the eluent) than NZVI-Ni (1%). In addition, PVP-NZVI-Ni reductively transform TCE to ethane even under 10 cycles of repeated TCE dechlorination treatment.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel NZVI catalyst was synthesized using polyvinylpyrrolidone (PVP) and Ni. </LI> <LI> Size of PVP-NZVI-Ni (20nm) is smaller than that of bare NZVI (50–80nm). </LI> <LI> PVP-NZVI-Ni showed a complete removal of TCE with superior dechlorination kinetics. </LI> <LI> PVP-NZVI-Ni exhibited better mobility than NZVI-Ni nanoparticles in column tests. </LI> <LI> PVP-NZVI-Ni showed a complete TCE removal up to 10 cycles without Ni release. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>