Reaction of decabromodiphenyl ether with organo-modified clay-templated zero-valent iron in water-tetrahydrofuran solution: Nano- to micrometric scale effects

Authors：Yu, Kai; Lv, Yanni; Liu, Cun; Boyd, Stephen A.; Teppen, Brian J.; Li, Hui^*

Source：Journal of Hazardous Materials, 2023, 445: 130538.

DOI：10.1016/j.jhazmat.2022.130538

• Decabromodiphenyl ether
• Smectite clay-templated nanoscale zero-valent
• iron
• Debromination
• Basal spacing
• Organo-modification

Smectite clay-templated nanoscale zero-valent iron (CZVI) was modified with tetramethylammonium (TMA), trimethylphenylammonium (TMPA) and hexadecyltrimethylammonium (HDTMA) to achieve organoclay-templated ZVI (OCZVI). The reactivity of various OCZVIs was evaluated on the basis of degradation of deca-bromodiphenyl ether (DBDE) in tetrahydrofuran (THF)-water binary solution. Characterization of OCZVI interlayer at nanometric scale indicated that the clay particles had the domains with three basal spacings in the THF/water solution. In the 50 % THF solution TMPA modification promoted the formation of the domains with a basal spacing at 1.56 nm, which could promote the degradation of DBDE. At the micrometric scale, in the 90 % THF solution TMA and TMPA modification tended to enhance the aggregation of OCZVI particles, while the HDTMA modification reduced the aggregation, and high percentage of modification yielded viscous gel struc-tures. The relatively rapid sedimentation processes in 90 % THF solution (compared to that in 50 % THF so-lution) and formation gel structures could reduce the access of DBDE to the interlayer reactive nZVIs, and lead to the significant reduction in reaction rate. These results provide important insights to the organo-modification on clays which could alter their orientations and dispersion in organic-water binary solution to achieve the desired reactivity on confined clay surfaces.

• Institution
  南昌航空大学; 中国科学院