Today's objectives are:
- Test 10% Bentonite beads with MG
- Test 10% Activated Carbon (AC) beads with MG
- Further test film swelling for more consistent data
Testing 10% Bentonite beads:
- A 50ppm stock solution of Malachite Green (MG) was prepared by adding 30mL of DI water to 10mL of the 200ppm MG solution prepared earlier.
- The plastic column with the 10% Bentonite beads was suspended on a ring stand and a rubber tube with a clamp wat attached to the bottom.
- 5mL of the 50ppm MG stock was then added to the column and allowed to filter through the beads at a flow rate of 13 drops per minute.
- This filtrate was collected in a labeled disposable scintillation vial and set aside for UV-VIS testing.
- The above procedure was repeated until the filtrate matched the color of the 50ppm MG solution
- At this point, 5mL of DI water was eluted through the column until the filtrate matched the color of the water.
- All samples were set aside for further testing.
Testing 10% Activated Carbon beads:
The Activated Carbon beads were tested using the same procedure as the 10% Bentonite beads.
Testing of the film swelling was performed on the 0.5mL glutaraldehyde films to see if we can get more consistent results. This was done by weighing 3 dried films, rehydrating them, and reweighing the hydrated films after patting them dry. The results can be seen below.
- 10% Bentonite beads
- 15 MG rinses, 4 DI water rinses
- 13 drops per minute
- 10% Activated Carbon beads
- 2 MG rinses, 6 DI water rinses
- 13 drops per minute
Clearly, 10% Bentonite beads were a far more effective adsorbent in comparison to the 10% Activated Carbon beads.
Table 1: Swelling data
As shown by the swelling data, only one of the film types had variable results. These were for the 0.5mL glutaraldehyde films. However, if we breakdown these films and categorize them by "larger" or "smaller" dried weights, we get a better sense of the results.
Table 2: Breakdown of "larger" and "smaller" 0.5mL glutaraldehyde films
When we categorize them into these more defined groups, we get smaller standard deviations. The reason for this is likely due ot the fact that the water on the outside of the films consists of a more significant percentage of the weight for the smaller films, which is why the swelling was around 543%. For the larger film, the water on the outside of the film is less significant for the larger films, which is why the swelling is only around 331%.