i agree 100% as engineer i have learn that the best solution usually is the simplest one, and nobody is best than nature and the way it works i have never seen a better system than humanuere composting toilets, but i requieres an open mind and a smaller ego.....
as example-.humanuere composting toilet http://www.youtube.com/watch?v=XXcU-JQFdms there is a "humanure handbook" for deeper understanding search on the internet PD sorry my english Manuel J. 2012/9/7 Duncan Martin <[email protected]>: > Eric and all > > Ingenious and no doubt workable - but it looks to me like the kind of silly > research that so many academics waste time and money on. (I speak as a > retired academic myself!) > > Lets consider the practical barriers to its widespread use - bearing in mind > that their video says that their aim is to provide an off-grid sanitation > system for use in developing countries. > > Cost - even with a minimal panel area, it wouldn't be cheap. > How many hours of sunshine - again with a minimal panel area - would be > needed for sanitization after one use? > Their little 'holding tank' supposedly allows AD to break down faecal matter > - but it would need to be very much bigger and more expensive to do so > effectively. > That combination of concerns suggest that it would not be remotely > affordable for individual households. Economies of scale would apply at > community level - but the size and cost of the solar array would multiply on > a more-or-less per capita basis (or maybe I should per backside!) so it > would still be expensive > With frequent use (especially at community level) the system might need > multiple treatment tanks operated on a timed sequence to ensure adequate > treatment time - more cost, more complexity. > They've thought of batteries to cover night use but what about cloudy days - > or weeks? There aren't many places in this world where the sun shines for > hours every day, whereas using the toilet is a daily need. Back-up > generators? More cost! Petrol to drive it? More cost! (Yes, AD stage would > generate biogas - but it would be very costly to store enough gas to fuel > the generator during a cloudy spell, which might last for weeks.) > All this complexity has to be maintained - and all systems would need to be > backed-up because of the risk of breakdowns, (One of the first design rules > for any kind of sewage treatment system is to keep it simple and very > reliable -- because shit just keeps on coming, so you can't shut down for > repairs!) > The overall environmental impact of manufacturing all this kit would be > substantial > Finally, several of the components are easily stolen (panels, batteries, > generators) and easy to sell on. My experience in Africa suggests that this > could be a major weakness. > So if one of these superloos ever gets installed in a real-world application > in a developing country, I wouldn't bet on it working for very long. We > might see them sooner in the developed world at sensitive locations (eg > national parks) - but even there the overall environmental benefit would be > open to question, so they might be mere greenwash. > > Bill and Melinda should spend their money on something more useful than > feeding the egos of researchers! > > Promoting low-tech reliable sanitation systems, which can be built operated > and maintained by local labour, would be a good start..... > > Duncan Martin > Cloughjordan Ecovillage > Ireland > > On 7 September 2012 00:39, eric roy <[email protected]> wrote: >> >> Hi Everyone, >> >> I was wondering if any of you have seen this system and can comment on it. >> I find it very interesting on how they're using some sort of >> electro-chemical cell to sanitize the supertenent outflow for water-reuse. >> >> >> http://www.huffingtonpost.com/2012/08/16/toilet-of-the-future-caltech-solar-powered-toilet-video-photos_n_1791874.html >> >> Do you think they're cycling salt water through out the system? or fresh >> water? >> How expensive and reliable this type of fuel cell is? I thought it was >> pretty cool, and would love to learn a little bit more about it. If you know >> more about this system please let me know. >> >> Cheers >> >> _______________________________________________ >> Digestion mailing list >> >> to Send a Message to the list, use the email address >> [email protected] >> >> to UNSUBSCRIBE or Change your List Settings use the web page >> >> http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org >> >> for more information about digestion, see >> Beginner's Guide to Biogas >> http://www.adelaide.edu.au/biogas/ >> and the Biogas Wiki http://biogas.wikispaces.com/ >> >> > > > _______________________________________________ > Digestion mailing list > > to Send a Message to the list, use the email address > [email protected] > > to UNSUBSCRIBE or Change your List Settings use the web page > http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org > > for more information about digestion, see > Beginner's Guide to Biogas > http://www.adelaide.edu.au/biogas/ > and the Biogas Wiki http://biogas.wikispaces.com/ > > _______________________________________________ Digestion mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org for more information about digestion, see Beginner's Guide to Biogas http://www.adelaide.edu.au/biogas/ and the Biogas Wiki http://biogas.wikispaces.com/
