Hello everyone!

This week in the N.E.W.T. lab at ASU we shifted our focus from small columns with crushed media to large columns with larger media to see if it worked as well, or better, than the small columns at removing bromide from water. I test some of the same media that I have been using (GCU blank, Clemsen GAC with silver,  Silver impregnated activated carbon) and a new media that is commonly used in water filtration called Purolite. The large columns were so much easier to pack and they all could run water through them with no pressure. It was so nice! Unfortunately, the columns did not work very well at removing organics. They reach a 50% breakthrough of organic compounds almost instantly. I hypothesized that the crushed worked better because there was more surface area for the organics to come in contact with and less space between the media. I will be interested to see if it removed bromide at all.

I was able to learned 2 new skills this week: sieving and silver impregnation. The silver impregnation procedure came from Clemsen and we wanted to replicate what they have done to see if we got the same results. What was different about this procedure is that they use Nitric acid to oxidize the carbon. That part was a little scary because when I was heating it to 90 degrees Celsius, the solution started bubbling and fuming. I survived though. We added to Silver Nitrate to the GAC and Zeolite media. I forgot how Silver Nitrate can stain your hands so I still have little black spots on my hand. The last step was to crush the media to 90 microns. This takes forever! I was covered in black carbon after.

We tested the media I made today along with a commercial Zeolite that was impregnated with silver. I couldn’t get the commercial Zeolite or the GAC with silver that I made to work, but I am very interested to see how my Zeolite with silver works at removing bromide.

I should finally get my bromide results back next Monday. Wish me luck!

(Unfortunately, my server wont let me attach pictures. I will try again when I get home. Sorry!)

-Taylor