Nanoscale zero-valent iron particles supported on MIL-96: a novel material for adsorption-degradation of trichloronitromethane.

Abstract

As an emerging class of nitrogenous disinfection by-products, halonitromethanes have caused public health concerns owing to their high toxicity. More and more attention has been paid to the new materials and technologies for the removal of halonitromethanes. In this study, a novel material, nanoscale zero-valent iron (nZVI) supported on MIL-96 (nZVI@MIL-96) with favorable stability and reusability, was synthesized and applied to the adsorption-degradation of trichloronitromethane (TCNM) in the water. The results revealed that almost all the TCNM could be removed under 20 mg/L nZVI@MIL-96 dosage with a wide temperature range. The optimum mass ratio of nZVI to MIL-96 was 1:2, and the TCNM adsorption-degradation followed a pseudo-first-order model. The coexisting ions, such as SO42-, PO43-, and NO3-, with high concentration brought adverse effects on the removal of TCNM; however, the effects of Cl- and CO32- were insignificant. The concentrations of aluminum and iron ions in water were all within the standard value after adsorption with the nZVI@MIL-96. The degradation mechanism of TCNM by nZVI@MIL-96 included two steps, namely, adsorption and degradation, and methylamine was the terminal dechlorination and denitration products. In a word, the as-prepared nZVI@MIL-96 nanoparticles demonstrated the capabilities as a material of adsorption-degradation of TCNM in the water.