Where do you get your bacteria? The air!

[Kungpaoshizi]

From another forum... I guess mass is mass when it comes down to it.
It would be interesting to see it applied to other weights..
(google 'how much does bacteria weigh' to find the rabbit hole)

Question:
What distance can airborne mining dust travel from a gravel mind operation?

While the answers given previously were terse and unhelpful, they are unfortunately correct. A large number of assumptions must be made in order to answer the question.

Before showing the results of any calculations, I feel it is only fair to mention that the actual amount of dust in the air will vary dramatically from day-to-day and hour-to-hour. While these calculations will show how far specific dust particles can theoretically travel, it is the actual concentration of airborne particles that should be observed. Furthermore, exposure to rock dust at small concentrations is generally deemed acceptable by labour and environmental agencies. A proper air sampling regime should be put in place to determine how often dust is being released and at what concentration. This test should run for a significant period of time to encompass as many temperature and other environmental variables as possible.

In order to calculate how far the dust can travel, the terminal velocity of the particles must be determined. This will allow us to find out how long it will take for the particles to fall from a particular height. Once this period has been determined, the distance which a particle can travel is a function of the wind speed.
(displacement = velocity * time)

Here are my assumptions:

1. The rock has a density of 2.5 g/cc

2. Ambient air pressure and temperature are 100 kPa and 25 degrees Celsius

3. The highest, and most severe, source of dust generation is 5 metres (16') off the ground, such as where a conveyor belt empties onto a stockpile of crushed material.

For anyone interested in double-checking my work, the assumptions above led me to the following parameters, required in order to calculate terminal velocity:

Air Density = 1.174 kg/m^3
Air Viscosity = 1.84E-04 g/cm-s
Gas Mean Free Path = 0.068 μm

Note that the units used for travel distances calculated below vary depending on particle size.

Calculations for 100 μm Particles:
----------------------------------

Dust of this size is well above the median inhalable diameter specified by the EPA. These calculations are included only to show how quickly this size material can fall to the ground.

The terminal velocity of this size of particle is calculated to be 0.573 m/s using the Intermediate Law for Fluid-Particle Forces, in the conditions specified previously.

It will therefore take 8.7 seconds for these particles to fall from a height of 5 metres.

Wind Speed____Travel Distance
5 km/h________12.1 m
10____________24.3
20____________48.5
40____________97.0
60____________145.5
80____________194.0


Calculations for 10 μm Particles:
---------------------------------

Dust of this size is the median inhalable diameter specified by the EPA. “The EPA describes inhalable dust as that size fraction of dust which enters the body, but is trapped in the nose, throat, and upper respiratory tract.” (Quote is from the cited webpage, below)

The terminal velocity of this size of particle is calculated to be 7.53E-03 m/s using Stokes Law for Fluid-Particle Forces, in the conditions specified previously.

It will therefore take 664 seconds for these particles to fall from a height of 5 metres.

Wind Speed____Travel Distance
5 km/h________0.9 km
10____________1.8
20____________3.7
40____________7.4
60____________11.1
80____________14.8


Calculations for 5 μm Particles:
---------------------------------

Dust of this size falls within the respirable dust range as specified by the EPA. “Respirable dust refers to those dust particles that are small enough to penetrate the nose and upper respiratory system and deep into the lungs. Particles that penetrate deep into the respiratory system are generally beyond the body's natural clearance mechanisms of cilia and mucous and are more likely to be retained.” (Quote is from the cited webpage, below)

The terminal velocity of this size of particle is calculated to be 1.91E-03 m/s using Stokes Law for Fluid-Particle Forces, in the conditions specified previously.

It will therefore take 2,612 seconds for these particles to fall from a height of 5 metres.

Wind Speed____Travel Distance
5 km/h________3.6 km
10____________7.3
20____________14.5
40____________29.0
60____________43.5
80____________58.1


Conclusion:
-----------

As you can no doubt see, by varying the particle size, wind speed and release height we can show that dust could end up just about anywhere downwind. In reality, the further the dust travels the more diluted it will become due to localized air movements and therefore become less and less harmful.

From a practical point of view, unless you are located particularly close to the dust source (<1 km) and/or are regularly inconvenienced by airborne rock dust, I do not expect that there is any cause for concern.

For more rock dust information see:

http://www.osha.gov/SLTC/silicacrystalline/dust/dust_control_handbook.html

 

[Randy Holmes-Farley Verified Community Expert]

OTOH, it is apparently well established that dust from the Sahara in Africa settles into the Carribbean and Florida each year:

http://onlinelibrary.wiley.com/doi/10.1002/2013GB004802/full

"Decades of aerosol measurements on Barbados have yielded a detailed picture of African mineral dust transport to the Caribbean Basin that shows a strong seasonal cycle with a maximum in boreal summer and a minimum in winter."

 

[Kungpaoshizi]

I guess I forgot to add, not every bacteria makes it everywhere. There's often talk that terrestrial bacteria are not marine appropriate, but if anyone wants to look into one that we know goes both ways, check out Bacillus. Quite an interesting bacteria! Some, even Dr. Tim, has speculated that it's probably responsible for working in part of our carbon dosing. This is a reason it's probably better than not to add some bacteria in a bottle from time to time.

Anyways, thought I would share this, came across this in reading, a good point that not every bacteria reaches everywhere around the globe! (can't say I've ever seen this one, and it's indeed marine based!)

The largest known species of bacteria was found in 1999 in the ocean sediments of Namibia, a country in southern Africa. Individual cells can be as large as 0.75 mm (750 µm), which is visible to the naked eye. The golden spheres inside the cell are accumulations of the element sulfur (S) from the surrounding environment. The shiny appearance and tendency of cells to group together in long strings inspired this species' name: Thiomargarita namibiensis ("Sulfur pearl of Namibia").

http://www.teachoceanscience.net/teaching_resources/education_modules/marine_bacteria/learn_about/

 

[brandon429]

KungPao that's good subject material about natural sources for filtration bac. Doesn't have to be bought

Doesn't have to be marine seed source in origination either, but online stuff posted by Dr Hovanec I believe it was showed DNA analysis of reef filter pad bacteria and 99% were marine specific, not finding those species in fw filters. Somehow they seed naturally but diverge I never got clarity on that do post any marine bacteria transmission studies you know

Someone right now in southern new Mexico no where near saltwater anything can set up a freshwater intended system as saltwater, input the consistent 2ppm ammonium chloride and maintain it, and still seed their whole tank with eventual marine filtration bacteria colonies just from septic prep techniques which is all aquarium practices including water changes and fills.
Boosting only the ammonia portion helps but natural sources of bac still have to seed in and grow... that kind of cycle could take upwards of sixty days to be able to oxidize the typical 1-2 ppm ammonia we look for in cycle completion.

Saltwater is no sterilizer for nitrifiers... of the natural seed sources contaminated into the tank selections and adaptations still get made and though it will take longer, that ammonia will still get oxidized in time and the tank will be able to pass 2ppm/24 hours digestion test like a normal setup can attain in four weeks with the bottle bac component included in the cycle.

aerosol transmission and airborne floc transmission of filtration bacteria does occur agreed and from what i read it has zones of prominence like waterfall areas, and zones of too dry conditions where simple fluid cross contamination and associations with other nonfilter bacteria are the vector. Cyano too, where goes nitrifiers so do the cousins

 

[Kungpaoshizi]

Oh no doubt, I'm not saying you HAVE TO add bacteria from a bottle. But if every type of bacteria were everywhere, life on Earth would be very different.
Though I do not know each and every strain in each brand of bottle, I believe probability dictates that not every beneficial bacteria from the ocean, is obtainable via air-transmission. If this were the case, e. coli, anthrax, vibrio that cause infections, and a host of other bacterias, though some not marine, would be a bigger problem.

I just assume add it since I'm not near the ocean, and in a different temperate zone, which influences a lot. All I'm saying is it's more beneficial to add some from a bottle from time to time than to assume they all make it to our tanks. Some people are in colder climates, and that prevents a lot of transmission. Then you have placement of the tanks, which may or may not be in a place where the air-exchange is even sufficient in the first place. These variables definitely answer the question of why some setup tanks and see the cycle sooner than others. Or even experience some blooms and algae nightmares that are quite different than other people in the hobby. Do we know every bacteria that is beneficial in the ocean? No. Do we have bacteria in our tanks that grow along hydrothermal vents? No. Can we say they're not necessary to marine environments? Nope..
There's a lot of unanswered questions which I do not assume to know, but probability is just that, better than blindly guessing, but still not a sure conclusion.

Here's some further reading that touches on differences. (even depth in the ocean evidently makes a difference)
http://www2.mar.dfo-mpo.gc.ca/science/review/1996/Li/Li_e.html
http://www.microbexpert.com/bacteria.html

Given how many bacteria there are, and how many different ways of transmission there are, I would bet my life savings on it, my tank in the basement which sees little airflow from outside more than half of the year (because of long winters) misses out on a lot of the beneficial bacteria that exist in marine environments.

One such statement that clearly shows we barely know anything at all about the ocean is this:
There are 100 million times more bacteria in the ocean than stars in the known universe, and there are a thousand times more viruses than bacteria. Yet we know little about the relationships between microbes and their environment because only one tenth of one percent of the bacteria have ever been cultured.
http://oceanworld.tamu.edu/resources/oceanography-book/microbialweb.htm

Though 6 years old, I doubt that 1/10 has increased much given how intricate the microbial systems are.
Just as vibrio that causes necrotizing events in humans are all throughout the ocean, only a few people have had it happen in their homes, caught from their tanks. But how many times have you reached into your tanks with a small cut or cracked skin and have had nothing happen? I know I've seen PLENTY of people argue there's no need for gloves in your home aquarium..

Only time and more research will allow us to formulate educated answers as to which strains we should have in our tank, versus the transmission and how they get there. Until then I don't mind paying someone a little bit of money to retrieve known beneficial strains from the ocean and put them in a bottle for me to manually transfer into my little glass box.

 

[Kungpaoshizi]

Here's something that is along these lines, interesting thought of 'what attracts'... Can't say I ever thought of them being "attracted" to things...
8:26 (whole vid is good tho)