Reductive debromination of tetrabromobisphenol A by Pd/Fe bimetallic catalysts

Reductive transformation of hexabromocyclododecane (HBCD) by FeS

“…Recent studies showed that zero-valent iron (ZVI) could reductively transform TBBPA, decaBDE and HBCD, and that the reduction rates tended to increase with increasing surface area of ZVI (Keum and Li, 2005;Lin et al, 2012;Tso and Shih, 2014;Yu et al, 2012;Zhuang et al, 2012). Bimetallic nanoparticles (such as Ni/Fe, Pd/Fe and Ag/Fe) were also reported to be able to rapidly debrominate either TBBPA or decaBDE (Fang et al, 2011;Huang et al, 2013;Luo et al, 2010). However, the abilities of naturally occurring solid reductants in sediments to transform BFRs are poorly studied.…”

Reductive transformation of tetrabromobisphenol A by sulfidated nano zerovalent iron

“…Further, the effects of S/Fe molar ratio, S-nZVI dosage and initial TBBPA concentration on the performance of S-nZVI in TBBPA transformation were examined. Unlike the previous studies in which a water/cosolvent mixture containing 50% of cosolvent (v/v) was used to prepare reaction solutions for TBBPA transformation by nZVI-based materials (e.g., Huang et al, 2013;Li et al, 2016a), here a water/cosolvent mixture with only 2% of cosolvent was used as the reaction solution in order to decrease the effect of cosolvent on TBBPA transformation. Therefore, the results of this study can help not only improving our understanding of the reactivity of S-nZVI with TBBPA and but also developing S-nZVI-based remedial options that may be applicable to various aquatic environments contaminated by TBBPA.…”

“…Several types of strategies have been devised to improve the reactivity of nZVI to target contaminants (such as TBBPA). Firstly, nZVI-based bimetals (e.g., Fe/Pd and Fe/Ni) were synthesized and demonstrated in the lab to have a greater reactivity towards TBBPA compared to nZVI (Huang et al, 2013;Li et al, 2016a). Secondly, the combination of either nZVI or nZVI-based bimetals with physical approaches (e.g., ultrasound assistance and microwave radiation) was found to be able to enhance the transformation rate of TBBPA (Luo et al, 2010(Luo et al, , 2011.…”

“…Thus, no external standards of these intermediate products were used for their quantification with the HPLC-UV method. Alternatively, the concentrations of tri-BBPA, di-BBPA, and mono-BBPA in aqueous phase were estimated from their HPLC peak areas based on the standard curves of TBBPA and BPA on a molar basis with compensation for the number of bromine atoms (Huang et al, 2013;Li et al, 2016a). The summed molar concentrations of TBBPA, tri-BBPA, di-BBPA, mono-BBPA and BPA of individual samples ranged from 96% to 105% of the initial TBBPA concentrations in respective batch experiments, which was consistent with the fact (as mentioned above) that no other TBBPA transformation products were detected by the LC-MS.…”

Enhanced dechlorination of 2,4‐dichlorophenoxyacetic acid by Pd/Fe nanoparticles in the presence of environment‐friendly iminodisuccinic acid

“…It could be that weak acidic conditions (pH = 5.5, 6.5) were favorable for the formation of enough H 2 which was then converted to active H by catalyst Pd . The passivation layers on the surfaces of nPd/Fe might be dissolved in acidic solution, which would yield more available reactive sites for 2,4‐D dechlorination. Conversely, at higher pH (pH = 7.5–9.5), the elevated OH − facilitated the formation of a passive film on the surfaces of nanoparticles, inhibiting the production of H 2 and preventing 2,4‐D from being able to contact reactive sites.…”