Part: 1
This article is
about the association of macroscopic thermodynamics substances and how it’s
related to the small particulate polymeric substrate size inside of a
Biocenosis Clarification Baskets (BCB). The bacterial adhesion on a solid substrate
like that of cat clay and its polymeric surfaces was tested for its
dissimilarities or its similarities to other filtration mediums.
Thermodynamics
and ponding, now there’s a topic you never hear or read about but play a very extensive
part in water quality and bacterial colonization. For those of you that are
looking to go that next step into leaning how and the whys of the Anoxic
Filtration Systems thermodynamics and bacterial polymeric adhesion this article
may help you in your understanding of such.
Some new pond
terminologies that twenty-five years ago were never heard of or were only
talked about in very small circles and mostly in scientific groups at that are
words like anoxic, facultative bacteria, permeability, porewater, convectional
movement, diffusion and now thermodynamics on a microscopic level. These words
have very little meaning to the unadventurous hobbyists because most don’t
apply or the complication of such fundamentally constructed idealisms of
thermodynamics is just too much for hobbyist(s) to comprehend and therefore its
best to leave information like that alone. But, if you’re reading my blog then
you are probably the more intelligent of that group of hobbyist out there and
taking that next step into microbiology is just another way to grasp what the
differences are with filters that do and those that don’t live up to the
expectation of the hobbyist(s).
When we talk about
polymeric surfaces the first thing that comes up is abrasive adhesion, which is
determined by the surface properties and its thermodynamic for the adhesion of
cells from a suspension onto a solid substrate used and having an affinity for
water are hydrophilic in nature. Hydrophilic substrates can be very
useful to hobbyist, especially for keeping water clean and uncontaminated by
biological or chemical insults. The adhesion of cells is determined by the
surface properties involved, i.e., the surface tensions of the adhering
particles of the substrate, and of the suspending liquid medium. In other
words, how fast is the liquid medium traveling over or through the substrate,
which the cells are to adhere to, and the mediums surface topography. In
essence, adhesion is more native to hydrophilic substrates (i.e., substrates of
relatively high surface tension) than to hydrophobic substrates (smoother
surface tension like that of plastic mediums), when the surface tension of the
bacteria is larger than that of the suspending medium then the opposite
prevails. The smoother a substrates has the less likely for easy bacterial
colonization.
Suspended bacteria
in the water column are useless to the hobbyist and will do very little in
water purification if the colonization is inhibited by hydrophobic polymeric
surface substrates made from example: sulfonated polystyrene, Teflon®,
polyethylene, and polystyrene mediums. Yet it is not uncommon to see filter
mediums made of any one of these plastics (most used in the food industry) with
the exception of Teflon®. Teflon® being too hydrophobic and disruptive, and has
the observed tendency to disaggregate bacteria in aqueous solutions. Good for
electrical wires used in high-end stereo connections, but not so for bacteria
colonization.
Most of the
microorganisms that make up the nitrogen cycle are polymeric dependent
according to surface tension and the number of bacteria adhering per unit
surface is dictated by thermodynamics. Manufactures of these synthetic mediums
know by testing, the number of bacteria adhering per unit surface area by image
analysis. The hobbyist would be quite surprised that some of these media
however may have lots of surface area (as stated in their advertisement) per
unit, but lower bacteria colonization than natural element(s) would. Natural
elements would be silica base or carbon base, i.e., clay, sand, rocks and
calcium carbonate that is used in labs for testing bacteria. We see this all
the time when hobbyist add more of a plastic media to a designated filtration
system to do the work that it was supposed to do with far less. These
shortcomings are determined by the available foodstuff, surface area per given
unit, carbon availability and its oxygen demand but also the thermodynamics of
a polymeric surface media used in applications for bacterial processes. The
last one alone will determine how long it will take for the bacteria to
establish colonies and resisting water shearing along with the number of cells
that will grow on the medium itself.
The research
conducted was to determine if these plastic polymeric surface substrates were
as good as or better than using a natural substrate like clay and would it
outcompete and have a better protocol. The test were conducted with
already cured filters substrates of not less than 90-days old and all polymeric
surfaces were tested and parameters were determined by using a
spectrophotometric analysis using the Hach, DR/2000 once again.
From the experiment
the establish number of nitrifying bacteria adhering per unit of micron surface
area would be established and seeing if they correlated well with thermodynamic
expected predictions that was calculated in advanced and that information would
then determine the surface tension resistance of the different bacterial
species correlating to the media used.
What was found is
that two 7"x7"x11" (177.8mmx177.8mmx279.4mm) BCB had as much
bacteria in them as an entire Nexus filter using K1 as a medium. However, the
Nexus with K1 had better utilization of the available autotrophic bacteria, due
to better media exposure and the AFS had a better usage of Heterotrophic
bacteria across the board with a much larger bacteria count. Which proved the
less confinement a media unit has the better bacteria uniformity exposure to
incoming insults. But this does explain why these filters need more media (K1)
units in them than expected.
Because the BCB is
static and water must pass around it and not directly through its medium
itself, the bacteria must depend on ions coming into them through slow
diffusion, chemisorption or ion displacement. If the media were to be exposed
like that of the K1 used in the Nexus filter then the medium would be
compromised and anoxic condition would not exists and like the Nexus then
nitrifiers would predominate. This then explains why so many BCB are to
be used; even though the bacteria count is high per BCB, the utilization of the
Heterotrophic facultative bacteria is slow to exposure to biological and
chemical insults and the bacteria can find other food sources as needed. But
the utilization of those foodstuffs was better in the BCB because of longer dwell
times inside the basket itself. Insults only needed one pass through the
filters BCB with better utilization of the entire available foodstuff exposed
to it than that of the plastic media that was being agitated taking several
passes through the medium. This explains why the Heterotrophic anaerobic
facultative bacteria attack nitrogen for its available oxygen and N2, nitrogen
gas, is its byproduct.
The Anoxic Filters
BCB’ has a higher good bacteria count than what is expected, but the
utilization of the special facultative bacteria in question could be better
optimally if the filter was reengineered to do so. However, to do this would
compromise the systems inexpensiveness to the hobbyist and then other
conventional filters would become the better choice. This also would explain
why in colder climates the utilization of foodstuff continues with such a high
bacteria count per BCB competing heterotrophs while other filters are teetering
on cold-water conditions destruction with a lesser bacteria count or are dead
altogether!
Plastic filter
mediums are great, as long as the hobbyist understands ahead of time that
adding more than what is recommended is the norm. Far year’s manufactures have known
this but it is a tricky balancing act to make the medium better in polymeric
surface properties without the negative responses of clogging the media, i.e.,
that of a bio-wheel with over a mile of fiber in one small wheel. In order for
the plastic medium to have a larger bacterial count per unit (1- FRI), the surface porosity would have to them be
increased like that of the crystalline structure of clay. Therefore, there is a
compromise that has to be recognized on surface properties of the filter medium
used and macroscopic thermodynamics polymeric bacteria friendly substrates.
1: It was not long
ago that advertisement showed little dimples in a plastic filter media made for
wet-dry filters. The theory behind the very small dimples is that it would
increase the polymeric surfaces of each unit and therefore the bacteria
population would also increase. The manufacture knew about thermodynamic
polymeric substrates and making a media that had more surface area increasing
the surface tension without the cost of clogging the small microporosity of the
unit.
part
1-2
