Speaker
Miranda Conley
Speaker's Institution
Colorado State University
Date
2022-02-16
Time
4:00 PM
Location
Chemistry A101
Mixer Time
3:45 PM
Mixer Time
Chemistry B101E
Calendar (ICS) Event
Additional Information

Literature Seminar:

 

The prevalence and use of plastic has long been a source of both environmental and human health concern. Plastic is produced using bisphenol A (BPA), a non-naturally occurring chemical, that may enter the environment due to wastewater, leaching from products, and through human waste. Humans, generally, are exposed to BPA through consumption of food or drink stored in plastic containers containing BPA. Due to public pressure, and in some cases government bans, manufactures have used bisphenol AF (BPAF) and bisphenol S (BPS) to manufacture their plastic products. However, BPA, BPAF and BPS all can have endocrine disrupting effects in the human body. The fate of BPA in the environment was poorly understood before the introduction of these derivatives, so an important task we face today is understanding how these compounds are transformed in the environment. Birnessite, a naturally occurring manganese oxide, is shown to be a powerful oxidant. Due to its prevalence in the environment, it is worth studying birnessite’s interactions with BPAF and BPS. Li, J. et al. (2018) employed three different high pressure liquid chromatography techniques in order to understand the efficacy, products, and varying conditions (such as mineral concentration, pH, and iodide concentration) of the interaction between birnessite and the BPA derivatives. Iodide concentration was a variable in this study due to its environmental presence and previous studies showing it enhanced BPA transformation. It was hypothesized that due to birnessite’s capability to oxidize iodide to molecular iodide and hypoiodous acid, the resulting transformation products may be iodinated. They show that birnessite was less efficient at transforming BPAF and BPS, however, found that high concentrations of iodide at neutral pH increased transformation extent. Several transformation products, iodinated and not, were identified along with proposed reaction pathways. Future studies will continue to focus on how the products may affect living systems, and how the mineral surface may be changed as a result of these interactions.

 

(1)       Li, J.; Pang, S. Y.; Zhou, Y.; Sun, S.; Wang, L.; Wang, Z.; Gao, Y.; Yang, Y.; Jiang, J. Transformation of Bisphenol AF and Bisphenol S by Manganese Dioxide and Effect of Iodide. Water Research 2018, 143, 47–55. https://doi.org/10.1016/j.watres.2018.06.029.