Name: トイレを塩水で流したら？ (What If You Flushed Toilets with Saltwater)
Uploaded: 2021-01-14T09:41:56.000Z
Duration: 8 min 7 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

Hey now, won’t you join me in the gutter for another look at waste water.

副詞形分詞節

Seriously, with fresh water being so hot an issue today, you would think people should

But then you flush your toilet and realize you’ve just spent several gallons of clear

Why can’t we use saltwater instead, for example?

Well, the short answer is it doesn’t, of course.

But the problem is there’s not much we can do about it, at least for now, and even saltwater

The modern sewage system works with the help of water that carries waste to the disposal

Water is perfect for this kind of activity as it keeps the waste afloat and pushes it

When it reaches the cleaning filters, the water simply seeps through, while the hard

stuff and particles stay on the kind of a grille, from where they are soon taken and

It’s obviously not clean after mixing with all that waste, so it goes into a huge tank

Heavier particles settle on the bottom of the tank and form a nice and slushy layer

It’s called sludge, and it’s then taken from the tank to use on farms.

The sludge gets some special treatment to make it usable as a fertilizer.

It’s not all organic in its, um, pure form, but it becomes nice for the soil after being

The water above the sludge, in its turn, becomes rather clear to the eye, but don’t let that

fool you: it has billions of microscopic dirt particles in it that only wait to infect you

So when the sludge has settled and got removed, the water gets its own treatment.

It either fills other tanks or goes through a special filtering system, but the basic

principle of both these methods is the same: waste-feeding bacteria.

If the almost clear sewage water rushes into tanks, you can be sure they have an atmosphere

The air is constantly pumped in to make them grow and multiply, speeding up the water cleaning.

If it’s a filtering system, then the water runs over specially treated stone slabs that

have overgrown waste-feeders living on them.

In any case, the water gets biologically purified and is almost ready to go back where it came

Almost, but not quite, since there’s one last stage of cleaning.

It differs depending on the country and rules.

The most popular method of finishing clean is treating the water with a disinfectant,

It makes the harmful bacteria left in the water vanish, effectively making it clear

Instead of chlorine, ultraviolet, peroxide, or ozone can be utilized.

Another way to purify the water involves pushing it through a special treatment tank, or a

humus tank, where even the tiniest particles and bacteria get stuck in the filtering matter,

It’s then released back into nature, and the cycle continues, or it can be used as

technical water for various purposes: from construction works and irrigation of non-edible

Such water isn’t generally allowed to be used for drinking, recreational or everyday

purposes, so you don’t need to look suspiciously at the flow from your tap.

But the question remains open: why not use saltwater instead?

We have literal oceans of the stuff, and we can barely find any use for it.

Well, there’s a huge trouble with salty water in the sewage system.

If you’ve ever swum in the sea, you know that if you lick your skin, it’ll be salty

And if you leave it to dry in the sun, you’ll also notice a thin smattering of white on

It washes off pretty well, leaving no trace, but that’s only because you haven’t been

Stay for a few days, and the white crust of salt will cover you much more visibly.

The same applies to almost any surface saltwater might touch.

If you simply send tons of water from the oceans into the plumbing and sewers, several

First of all, salt from the water will begin staying behind as a residue — just like

Now you can wash it away, but still the salt is corrosive.

Metal, clay, and concrete all eventually give up to it, and pipes burst.

And secondly, the resulting wastewater will not be able to return to the oceans just like

that, or be used for other purposes, for that matter.

Like I said earlier, fresh sewage water goes through several filters, one of them biological.

Bacteria spread in the water and munch on everything harmful they can find around.

With saltwater, such a system won’t cut it: the good bacteria can’t survive there

So there’s at least the problem of installing a new system of filtering and cleaning of

saline water — and you can guess it’s crazy expensive.

Not only that, it’s crazy difficult too.

Just imagine having two separate pipe systems underneath your town: one for fresh water

we use every day for cooking, washing, and other stuff, and the other for saltwater to

Yep, you’ll still have to have fresh water for your daily activities, because trust me,

But there’s still never going to be a way to use the cleaned saltwater for farming and

some other needs — it will have to be desalinated first, and that’s another obstacle.

That doesn’t mean we can’t use sea water at all, though.

We are, in fact, using it already, and have been for quite some time.

There are several desalination plants sprinkled across the globe that work hard to convert

They filter and vapor out the salt from the water, leaving behind huge piles of dry stuff,

while the liquid goes further and eventually gets to homes and industries.

Leftover salt is then used for various purposes too, and you can even be consuming it with

The existing desalination method is not perfect, of course, but it’s proven its efficiency.