Most of us don’t give a second thought to where it ends up after flushing
but what if I told you that that very poo
could be making its way back into your house
without you ever noticing?
For those unfamiliar
once your food has been chewed, swallowed, chemically and physically broken down
and the useful nutrients have been absorbed into your body
the rest is gracefully discarded as waste
This waste then gets combined with a
mixture of with a mixture of urine, rain, shower, sink
and other household waters into your local
sewer system which surprisingly
contains mostly water and relatively
little faeces like a big old
bowl of soup with very few vegetables
After passing through potentially miles
of pipes, the soup reaches the sewage
treatment plant and is initially screened
and skimmed to separate out things like
sand, grit and pebbles.
More importantly, this is where that cellphone you accidentally dropped down the toilet
gets caught along with condoms? and other stuff you thought would be a good idea to toss down the drain.
Which by the way wasn’t a good idea.
For every piece of trash or item you throw down the toilet
the more likely there will be a blockage in the system which has to be removed
And no-one wants that.
The pebbles and grit, on the other hand, are
dried, cleaned, and reused for things like construction
Perhaps contributing to the creation
of your ivory throne.
The remaining poopy mixture is then left still
In a giant tank.
And thanks to the fundamental properties of both
oil and grease as non-polar substances,
which don’t mix with water,
it’s relatively easy to skim them off.
Still, you really shouldn’t be putting
it down the drain, as it can clog pipes
and overwhelm the intricate system.
What’s left now is some sludge and a
smelly liquid that looks like chocolate milk.
Mmm, chocolate milk!
And that’s what it tastes like to the millions of bacteria
which are set loose to feast on this
mixture. They literally eat the pathogens
out of the liquid
Most of these bacteria are aerobic,
meaning they require oxygen to function,
just like humans,
so the tank is pumped full of oxygen.
This water is then disinfected and
reintroduced back into the environment.
The remaining sludge on the other hand,
Containing mostly solid waste matter,
goes through a final treatment with another set
of bacteria. These bacteria produce
a variety of by-products including methane
gas, which in turn is used to power
the sewage treatment plant.
So your poop powers the plant that
processes your poop.
After eating everything, the bacteria die
and create something known as Biosolid.
After all is said and done,
The remaining, nutrient rich faeces and Biosolid
can be used to make compost to
enrich dry land, or used as fertilisers,
which ultimately help grow vegetation.
Vegetation which makes its way
into your house and ultimately
into your mouth.
And so begins the cycle of poop,
All over again
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