Journal
CHEMICAL ENGINEERING JOURNAL
Volume 414, Issue -, Pages -Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.cej.2021.128780
Keywords
Ferrous mineral; Phosphate adsorption; Electron transfer; Dioxygen activation; Oxidative detoxification
Categories
Funding
- National Natural Science Foundation of China [21876161, 51978537, 41807188]
- GDAS' Project of Science and Technology Development [2019GDASYL-0102006]
- Start-up Fund for Distinguished Scholars, Wuhan University [1403-413100041, 1403-600460022]
Ask authors/readers for more resources
The transformation of green rust to form ferric oxyhydroxide is important in iron cycles in subsurface environments. Phosphate enhances the generation rate of hydroxyl radicals during green rust oxygenation. Phosphate decreases the electron utilization ratio of green rust but increases the electron selectivity for hydroxyl radical production under oxic conditions.
The transformation of green rust (GR) to form ferric oxyhydroxide at the oxic/anoxic interface, is an important process of iron cycles in subsurface environments. However, little is known in its electron transfer process and environmental impacts. Herein, we demonstrate that the GR oxygenation can generate hydroxyl radical (?OH; 1.6 ?M) with a low rate of 0.012 ?M/min. Interestingly, a strong correlation between the adsorbed phosphate on GR and the ?OH generation is found; the presence of 20 mM phosphate significantly enhance the generation rate of ?OH up to 0.13 ?M/min, and a high cumulative concentration up to 20.9 ?M. Our results demonstrate that the formation of iron-phosphate complexes is likely a key species determining ?OH generation. Electrochemical analysis and DFT calculations indicate that phosphate can decrease the electron utilization ratio of GR but notably increase the electron selectivity for ?OH production under oxic conditions. Subsequently, the generation of ?OH radicals plays a role in oxidatively detoxifying diverse organic pollutants (e.g. chlorophenol and pharmaceuticals). Our findings provide new insights into the important role of oxyanions such as phosphate in determining electron transfer during iron cycles and consequently the fate of pollutants in subsurface environments.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available