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Pee-cycling … and a more sustainable life …

March 6th, 2007 · 3 Comments

Learn something every day … perhaps even many somethings.

With the New Year, New Scientist taught me something about my (our) bodily fluids and the implications for the waste system — and, through that, energy, water, sustainable lifestyles, governmental budgets, Global Warming, and what I want to see in far more homes and office buildings.

It turns out that pee, while just “1 per cent of the volume of waste water, urine contributes about 80 per cent of the nitrogen and 45 per cent of all the phosphate. Peeing into the pan immediately dilutes these chemicals with vast quantities of water, making the removal process unnecessarily inefficient.”

And that inefficiency leads to more energy use, more fiscal cost, and — perhaps — a missed opportunity as, perhaps, we should engage in Pee-Cycling …

New Scientist‘s special report Pee-Cycling begins …

You recycle your household waste. You buy locally grown food, fit low-energy light bulbs and try not to use the car unnecessarily. Maybe you even irrigate the garden with your bath water. But you’ve still got an environmental monster in your house. Your toilet is wrecking the planet.

Before you point to the brick you’ve put in the cistern, it’s not about the water – well, not entirely. The big problem is pee. Your pee. Do you flush it away without a second thought? Tsk, tsk. Lose the green halo.

I don’t know whether to laugh … to cry … or to run outdoors to pee behind the bushes.

The author, Graham Lawton, certainly has a way with words if can create this level of confusion within those few paragraphs.  This article brings to our attention to a toilet development that I heard of but really didn’t understand prior to this article.

To be fair, if you use conventional western plumbing there’s not an awful lot you can do about your personal pee-print right now. A lucky few, however, live or work in one of the buildings in continental Europe where you can find a future must-have eco-accessory: the urine separation toilet. These devices divert urine away from the main sewage stream, allowing the nutrients to be recycled rather than treated as waste. They could solve all the environmental problems associated with urine and even turn sewage plants into net producers of green, clean energy.

Well, this article started me off on a little search and one can be amazed by the worlds that you have no awareness of … how many Kossacks attended, do we think, the DRY TOILET 2006 — the 2d International Dry Toilet Conference in Finland last August? Well that might seem satirical (A toilet conference, let alone a dry toilet conference?), in fact we should be heartened by the dedication to developments like these of a specialized few — and reminded, yet again of the complexities of interactions required to move the human race toward a sustainable level of use (rather than current) abuse of the planet — its energy and its other resources — before our past (and current and coming) abuses drive the planet past a breaking point in terms of supporting the human race (or at least a very large share of it).

Why Finland, other than it is a great place to visit in August, one might ask?

About a million people, or some 20% of the population of Finland, live in houses that are not connected to centralised sewerage systems. This means that about 350,000 permanent residences and a further 450,000 holiday homes must treat their own wastewater treated ‘on site’. The treatment systems in very many cases are obsolete or otherwise ineffective. Because of the big amount of holiday homes, Finland is actually the promised land of dry toilets.

The conference did not have a focused solely on the high-end of the developed work like Finland:

Water is a scarce natural resource. In 2002, 82 % of the world’s populations had an adequate water source to use, but only 58 % had access to adequate sanitation. The lack of sanitation is concentrated to certain areas in the world, as rural areas, and often to the development countries in Asia and Africa. Poor sanitation also represents an environmental threat to the quality of the water, both in areas with a lot of water and a little water.

If there is no clean water, diseases and other problem tend to spread. If even the sanitation is insufficient, we face terrible death rates, especially for the children. Dry toilets and the know-how connected to them represent one way of coming to functioning solutions in these issues.

Thus, dry toilets — ways of handling waste better without straining poor or even non-existent sanitation systems — could help on many fronts.

But, let us go back to the issue of ‘pee-cycling’.

For the UK, “waste water treatment consumes 65,000 gigajoules a day – about a quarter of the output of the country’s largest coal-fired power station.” Research suggests that diverting half of the urine content could come close to eliminating this demand on the power system as “the microbes in the aeration tanks could eat up almost all the nitrogen and phosphate (Journal of Environmental Engineering, vol 132, p 331). The energy-intensive polishing stage would become completely unnecessary.” [NOTE — don’t ask me for an explanation of this — someone else will have to come to the rescue on that …] And, with all the efficiencies associated with dumping otu the urine, research suggests that waste-water plants could actually become power producers while producing cleaner water.

So, how does it work …

On casual inspection a NoMix toilet looks pretty much like a normal one. But peer into the bowl and you’ll see that there are two waste pipes – a small front one and a larger rear one. The front one collects urine and diverts it into a storage tank (sometimes aided by a tiny trickle of water) to await its fate. The rear works like a standard flush toilet.

You don’t even have to do anything special to make this separation happen – apart from one thing. “The toilet is constructed in a way that if a man or woman sits on the toilet most of the urine is collected,”

Hold it there horsey … that is where the real problem lies. Of course, pee-cycling faces cultural challenges — as is true with so much of what we must seek to achieve for a better tomorrow.

One of the requirements for use of urine separation toilet pedestals is the cultural shift required of men: they must sit down to urinate, as the urine catch-tray is at the front of the unit. (source)

On the other hand, how much will these toilets contribute to social stability by ending arguments about “you didn’t put the seat down again …”

If there were mass introduction, what would we be doing with the all this pee? (I, for one, really don’t want to know the calculation for daily pee in Paris, New York, or Washington, DC …)

The answer is, recycle it indirectly – in other words, extract the nutrients and turn them into fertiliser. …. help reduce demand for mined phosphate, which can only be a good thing: phosphate rocks are often contaminated with heavy metals, and mining and refining them generates waste and uses lots of energy. Some estimates suggest the world’s phosphate mines will be exhausted in 100 years. Yet at the moment we literally pour tonnes and tonnes of perfectly good phosphate down the drain.

And, of course, things get better as urine-separation toilets are flushed less frequently — by as much as 80 percent and cut overall household water use by perhaps 25 percent.  Remember, it costs money AND energy to make clean water. Plus, water is an ever more scarce good throughout much of the world.  This is one path toward reducing demand.

Well, as suggested in the article, not many of us are likely to see that urine-separation toilet as part of our daily lives in the near future …

Of course it would take time and money to convert existing sewage systems. But even if urine separation isn’t coming to your area any time soon, that’s not an excuse for inaction. Keeping urine out of the waste stream any way you can pays dividends. So what are you waiting for? Next time you need to take a leak, give the bathroom a miss and head straight for the flower beds. Then you can replace your green halo.

Ahh, so my last reaction to the opening paragraphs wasn’t such a bad one. Excuse me if I don’t respond immediately to your posts as I need to step outside to water the plants … and restore my green halo.

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Imagine … Imagine a coming infrastructure where the average home has composting toilets, public facilities and office buildings have waterless urinals which keep urine out of the waste stream and urine-spearation toilets are the standard … and where waste-water plants have become part of the base-load providers to the electrical grid …

Crossposted (discussion had 40+ comments).

Tags: eco-friendly

3 responses so far ↓

  • 1 Energy COOL: Searching for the Perfect Flush // Nov 1, 2009 at 10:21 pm

    […] toilet) to introducing technology that has a shocking impact on some people’s sensibilities (waterless urinals or combining sinks with toilets) to the moderate and more socially acceptable replacing of an […]

  • 2 Energy Bookshelf: the green blue book // Dec 22, 2009 at 3:18 pm

    […] around the globe.  With all my attention to energy and environmental issues, including more than a little to water issues (including Energy COOL ways to cut one’s own water consumption), I’d never actually […]

  • 3 Bob Knows // May 30, 2014 at 5:57 pm

    I lived in Albuquerque, NM, USA. They have perennial water shortages. I calculated that if half the people would just go outside and pee in their garden or lawn it would save the city a million gallons of fresh water per day or more. It would also be good for the lawns and gardens. Even the zeroscape cactus yards could benefit from extra urine. People don’t need special toilets and plumbing, just the motivation to save water and fertilize their yard.