During the first week, I got to meet with my mentor Justin Kidd along with Mariana Lopes, who are Ph.D. students at ASU that work under Dr. Paul Westerhoff. We did a lab tour and they showed me around the building ISTB4 at ASU’s Tempe campus.
The project I’m going to be working on is about removing bromide ion from drinking water. Bromide ion (Br–) in drinking water can react with disinfectants (chlorine, ozone, etc) to produce inorganic (bromate) and organic (e.g., bromoform) by-products, which are human health concerns.
The following is my research experiment for the summer:
Step 1: AgNO3 + NaBr –> AgBr(s) + NaNO3(aq)
Step 2: AgBr + hv -> Ag0 + Br–;
UV irradiation into the aqueous solution gives energy so that the reaction AgBr(s) + e-1 –> Ag0 + Br–(aq) can occur, water donating the electron.
Step 3: Demonstrate that placing Ag0 from Task 2 into water containing Br– or Cl– produces AgBr or AgCl. This would be the first confirmation that the process is recycling silver ion.
Task 1. Dissolve silver nitrate into ultra-pure water, adding different concentrations of sodium bromide to observe how long it takes for this to react and if it precipitates. Confirming the formation of these silver bromide or silver chloride nanoparticles is the first step.
Silver Bromide after 60 minutes
Task 2. Determine at what concentration particles start to form. This can be done by measuring nanoparticles using UV/VIS scans. Then, find a way to separate the precipitate from the aqueous solution.
