Sediments
from the San Pedro river + 1g CaSO4
After
two weeks, on the illuminated side (Photo 3) we can be observed green
filaments and small pockets of air, which may correspond to
photosynthetic microorganisms that produce O2 (air bubbles). On the
other part where there is no light (Photo 4) we continue observing
larger and larger black spots (developing colonies, which are caused
by microorganisms that use sulfate as an electron acceptor and
transform it into hydrogen sulfide, which reacts with iron causing
black iron sulfide (II). The orange color also corresponds to an
iron compound, but this time it is iron oxide.
It should be
added that there is a small plague of snails on the surface of the
column, at the boundary between the water phase and the solid one.
On the no illuminated column (Photo 5 and 6) there are many more
black spots corresponding to the hydrogen sulfide mentioned above. On
the surface, however, there is a kind of reddish fuzz which could be
iron oxide.
improving, good job! Let's see what happens to te column.
ReplyDeleteExcellent!
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