Parameters that influence the zero valent iron mediated degradation of the pharmaceutical diazepam (DZP) were evaluated including the iron concentration and its pre-treatment, the effect of complexation with EDTA and oxic versus anoxic condition. It was observed that acid pre-treatment of iron particles is important for degradation efficiency and that H 2SO 4 is a better choice than HCl, resulting in higher degradation of DZP. Under oxic conditions, the degradation of DZP achieved 96% after 60min using Fe 0 (25gL -1) pre-treated with H 2SO 4 in the presence of EDTA (119mgL -1), while mineralization achieved around 60% after the same time. Under anoxic conditions, degradation occurred, however at lower extent, achieving 67% after 120min. The addition of EDTA improved the treatment efficiency in 20% leading to 99% DZP degradation after 120min. The first intermediates formed during DZP degradation were identified using LC/MS analysis and revealed the formation of mono- and di-hydroxylated products from DZP during Fe 0/EDTA/O 2 degradation, which evidences that OH was the main oxidizing species formed in this process. © 2012 Elsevier Ltd.
Bautitz, I. R., Velosa, A. C., & Nogueira, R. F. P. (2012). Zero valent iron mediated degradation of the pharmaceutical diazepam. Chemosphere, 88(6), 688–692. https://doi.org/10.1016/j.chemosphere.2012.03.077