(Continued from yesterday)
THERE is a prevailing theory that human excreta could not be tapped for biogas, because it is not potent enough. There is, however, a solution to that problem, because the potency will increase when animal wastes are added to human excreta.
There should be no problem doing that in the rural areas, but there is also an alternative to use environmentally safe additives that could be as good as animal wastes in increasing the potency of human excreta. On the question of what to do with food wastes and other kitchen wastes, these could either be added directly with the mix of wastes, or be fed to earthworms by way of vermiculture. Mature earthworms could then be used as protein sources for animal feeds and vermicasts could be added to the mix of wastes or used as organic fertilizers.
Green cities and smart cities are not necessarily one and the same, because it is possible for a city to be green and yet not smart and vice versa, it is possible for a city to be smart and yet not green. Rather than chose one over the other, I would rather have intelligent settlements that are both green and smart, and they need be cities actually, because they could just be small villages everywhere, even in the remote islands and the isolated mountains.
The common denominator between green and smart is sustainability and affordability. These two should actually work together, because nothing could be sustainable if it is not affordable.
Needless to say, it is energy that is at the core of everything that is green and smart. For one, energy can produce clean water that in turn could be used to produce food. As energy becomes cheaper, everything that depends on it would also become cheaper, such as water and food.
Producing biogas, however, is just one way to produce and save energy. Other than the obvious renewable sources such as wind and solar, there are many other sources that are waiting to be tapped, such as river flows, waterfalls, ocean waves, gasifier and even solid wastes.
Gasifier technology is also known as dendro thermal technology, meaning the use of commercially grown wood species to produce the feedstock.
Although I am open to the idea of burning solid wastes to produce electricity, I think that it would be such as waste (pun intended) to just burn any material that could be recycled. In theory, recyclables are not garbage because of their commercial value.
That is the reason why I say that any village or city that does not have a materials recovery facility (MRF) could not claim to be green. More so they could not be considered smart, if they are too dumb enough to just dump recyclables into a dumpsite or bury them in a landfill.
On top of that, they also could not be considered smart if they do not collect rainwater or recycle used water./PN
