SUCCESS! We have finally gotten enough data to determine the concentration at which the flux begins to decline for MD. Monday, we get two new membranes to use, and soon we will have the windowed cell’s dimensions altered to suit our higher flow rate needs. Other than the altered cell and a laptop that can record our data, our second MD system is complete and ready for use in MD experiments. We’re also still waiting on another hot water bath for the system, but for now we are improvising with a 4L beaker on a hot plate. The last run we did lasted 40 hours with our .45 um membrane, which is a lot longer than we’ve run any other experiment. This is partly because we started with a higher volume of 2X NEWT O&G water and partly because the membrane is thicker and therefore has a lower initial max flux. We ran it until the water (1L) was pretty much completely gone. It was pretty neat. The leftover feed water looked gross as heck because it was full of slimy-like salt deposits (it was SUPER concentrated by the end) and appeared sort of foamy because of the bicarbonate ions breaking down into CO2 gas. Next week, we should be able to start taking samples of the membranes starting and stopping at specific concentrations to compare the scaling for each. Something interesting I’ve noticed this week with the longer-running experiments is that scaling tends to be higher at the far end of the membrane, near where the water exits the cell, and lower at the water’s point of entry into the cell. What’s cool about this is that I had just recently read a journal about something similar happening in other MD experiments.
On another note, a bunch of the grad students and even some of the faculty got together last night to sing some karaoke at an Irish pub across the street from campus. It was a TON of fun! This week I’ve been enjoying getting to know my lab mates better and they’ve been showing me all the cool food places nearby. If you want the best burger of your life, go to the Chuckbox on University Drive. I’m serious. You will die and go to heaven and then come back again to take another bite. It was fantastic. Also, I had some pictures for ya’ll this week, but then I dropped my phone in the toilet. ¯\_(ツ)_/¯ Oh well. I’m sure you’re tired of seeing my MD setup anyways. It doesn’t change much. Maybe I’ll post photos of our used membrane samples next time.
Can’t wait for our long Fourth of July weekend! Hope you all stay safe and have a blast. 🙂
Sky
Making progress is always exciting, isn’t it? I’m also glad to read that you are having a good time with your labmates!