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.

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