new toilets: round 2 goes to the Swiss

As I’ve mentioned before, the Gates Foundation is funding research to reinvent the toilet for the developing world, with minimal water use and maximum energy output (no-waste toilets).  A group from Caltech won the competition, and a group from Eawag (the Swiss Federal Institute for Aquatic Science and Technology) won the award for “best user interface”.  (Having done part of my PhD at each institute, I’m certainly proud of my former colleagues.)  In other words, round 1 went to the “Star Trek” toilet, as I’ve heard it described, with a consolation prize to the “more likely to be used in the developing world” toilet.

It looks like round 2, the implementation phase, will begin in Durban, South Africa, which is plagued by limited water supplies and rising consumer demand for fancier flush toilets.  Middle class isn’t quite the same when you still have to use a pit toilet.  With your neighbors (mandatory cringe from all of us in the developed world).  The city of Durban has entered a partnership with Eawag and the Gates Foundation to build no-waste toilets for the 230,000 families among the 3.8 million inhabitants of Durban that still lack access to safe and hygienic toilets.  Round 2 appears to go to the Swiss!

Given that the upcoming World Toilet summit (yes, that’s a real thing) will take place in Durban this December, this looks like a huge win for the Swiss, especially in the realm of getting more contracts.  The Americans will have their work cut out for them, if they want to make a comeback in round 3, location TBD.

correction about toilets

I wrote last month about the Gates Foundation’s competition to design a new toilet, and I mentioned that Eawag declined the chance to compete.  That was completely wrong.  Eawag did compete, and their design won the award for best user interface.  Congrats to team leader Tove Larsen.  I have to say, the schematic of their squat toilet looks a lot more likely to be accepted in parts of the world like southern Asia, where I have observed the ubiquity of squat toilets.  Their design also minimizes water throughput.

That said, the winning design from Caltech is impressive in other ways.  It is big and fancy and space-age.  It fits that the design was first produced for NASA.  But astronauts don’t make up the bulk of the population that needs access to toilets.  So it will be interesting to see who “wins” the implementation phase of the competition.

the wave of the future

There are people out there studying global cycling and reserves of elements.  Carbon cycling is well known, from climate research, but there are headlines now and again about trace elements that we might run out of — tantalum, neodymium, germanium, gallium — that play a role in industrial products or processes.  But the really scary numbers are for phosphorus, if you believe the USGS estimate of current reserves: peak production by 2030 and exhaustion of the global reserves by 2100.  Remember, phosphorus (along with nitrogen) is responsible for revolutionizing our agricultural yields in the mid-1900s, and farmers throughout the developed world use it heavily.

The reason why I think phosphorus scarcity is a good thing, is that there’s another obvious source of phosphorus in the world: human and animal wastes.  When the price of newly mined phosphorus gets high enough, projects to recover phosphorus from wastewater treatment plants or feedlot manure piles will be economical.  This type of “recycling” phosphorus is, in my humble opinion, more sustainable in the long term than the typical “use it and throw it away” thinking we have about, well, everything we use.

It’s refreshing to see that my line of thinking is shared by those in the Encina Wastewater Treatment Plant in Carlsbad, California.  They performed a pilot study last year and have begun evaluating the cost-effectiveness of implementing a full-scale system to recover phosphorus in little pellets to be used as fertilizer.  The pellets are composed of phosphorus, nitrogen, and magnesium in a mineral called “struvite”.  Researchers at Eawag have found that struvite precipitates more readily from urine than mixed wastes, and they have therefore pushed for “source separation”.  (Side note: It wasn’t the best thing to be the subject of their urine collection system while I worked there.)

Think about some of these trends, though.  Wastewater treatment has historically been about meeting some minimum level of treatment so that wastes could be dumped into our waterways.  Between the biogas recovery and fertilizer production, there is a shift towards viewing wastewater as a potential resource instead of a waste stream.  Any way to recycle these “wastes” back into productive use will lead to not only greater sustainability for wastewater treatment, but also larger profits for the treatment plants.  I will post more about this when it comes to the Los Angeles water balance, but it is worth noting that most of what exits a wastewater treatment plant is water.  If we could recycle this, too, wastewater treatment could be a huge boon to the energy, agricultural, and water needs of our society.  Now that’s impressive.