Colorful stones sit in the bottom of the
water; happy fishes swim back and forth in the Genesee river. What a
beautiful view! Mm... I cannot help imaging this scene... Ok, I admit I
am cheating myself. Let's go back to the real world. The river isn't
that clean. I wonder what is in the water to make it so "dirty"?
Our lovely Electron Microscopies jumped to my mind at once.
So, the wonderful jounery of exploring begins. Let's see....
The following images are all
micrographs taken using the secondary electron imaging technique (SE2).
As we can see in the imaging proecess, there are abundant "stones"
in the water as shown in figure 1. Through EDS analysis (the graph is
shown below), we know their compositions are CaCO3. The turbidity of
water are caused by this kind of stuff. There are also diatoms in the
water, as seen in figure 2 and 3. A crystal shape matter is also
identified, see figure 4. EDS analysis indicates that it consists
of Ca, P, O.
Figure
1. CaCO3 and Fiber
Figure 2 Diatom
Figure 3 Diatom with high
magnification
Figure 4 Ca, P compound
2. SEM-Backscatter Electron
Imaging
The following micrographs,
CaCO3 grains and diatom, were taken with backscatter electron imaging
technique. As we can see, we can not see to much information from this
technique for lacking of heavy metals. Figure 5 CaCO3 grains by
BSE
Figure 6 Diatom by BSE
3. SEM-EDS
EDS is also used to
characterize the stones shape matters which turns out to be CaCO3, the
microorganism which is diatom, and the crystalline shape stuff which
shows the Ca, P compositions.
Figure 7 CaCO3 grains
Figure 8 Diatom
Figure 9 Crystal Shape Compound
4. TEM
I also tried to
find intereting stuff by TEM technique and used TEM-EDS to characterize
the composition of matters. There seems to be some heavy metals in the
water, which means the water might be polluted slightly.
Figure 9 Image of Heavy Metal by TEM
Figure 10 Heavy metal
composition by TEM-EDS
