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

  • ha.

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

  • save every drop of the precious liquid.

  • But then you flush your toilet and realize youve just spent several gallons of clear

  • water only to get rid of your waste.

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

  • How’s that saving the planet?

  • 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

  • isn’t a solution.

  • I’ll explain.

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

  • plants.

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

  • through the pipes.

  • 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

  • dumped or recycled.

  • Next the water goes for settling.

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

  • where it sits for some time.

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

  • of grime.

  • 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

  • treated correctly.

  • 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

  • if you have a drink.

  • 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

  • inside that’s beneficial for bacteria.

  • 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

  • from, meaning seas and oceans.

  • 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,

  • such as chlorine.

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

  • and ready for use.

  • 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,

  • while the water freely runs onwards.

  • 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

  • crops to cooling nuclear plants.

  • 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.

  • It’s okay.

  • 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.

  • You see, salt is hard.

  • If youve ever swum in the sea, you know that if you lick your skin, itll be salty

  • to taste.

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

  • your skin.

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

  • in the water for long.

  • 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

  • things will happen quite soon.

  • First of all, salt from the water will begin staying behind as a residuejust like

  • that salt on your skin.

  • 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

  • because of all the salt.

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

  • saline waterand 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

  • flush our toilets.

  • Yep, youll still have to have fresh water for your daily activities, because trust me,

  • you don’t want to cook in sea water.

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

  • some other needsit 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

  • sea water into fresh one.

  • 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

  • your food.

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

  • You can even drink the water after it has been devoid of salt!

  • And certainly, it’s used for other everyday activities, including flushing your toilet.

  • Okay, saltwater might be one solution to reduce excess use of water, but there’s another

  • way to do it and you know it pretty well, I guess.

  • I’m speaking about composting toilets.

  • The basic principle is that everything you throw in there goes into the soil and keeps

  • there for some time, until it turns into humus.

  • It isn’t as simple as dumping soil into the ground, of course: there’s a composting

  • unit with three chambers that evaporates the liquid, which makes up for 90% of the human

  • waste, helps bacteria flourish, and eventually makes a safe and non-smelly compost.

  • Sounds awesome, but the trouble with such eco-friendly toilets is that they aren’t

  • practical in big cities, since most people there live in apartments, and you can’t

  • simply install a composting unit in an apartment building.

  • To do so, it will require a separate waste disposal system of its own, and given how

  • composting toilets work, it will most probably cost even more than all the pipes for saltwater.

  • In rural areas and smaller towns, though, where people live in their own homes, composting

  • toilets are the best possible solution.

  • They don’t need any water at all, collecting all you have to throw inside them with quiet

  • dignity and then dumping it into the soil, making it richer.

  • And that’s my latest scoop on poop.

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

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