Re: Energy from Dung in Karachi?!
Abey yar sewerage treatment plants are something else.. treatment plants “treat” the dirty water, i.e. neutralize it, and then release it into rivers and streams, that’s what’s being done here in Canada and elsewhere. Perhaps you’re talking about simple water tankers, they gather water from rivers and streams and then use it for gardening; they pretty much get the water from the same places as drinking water. Drinking water/ water for human use is usually treated in some way (sedimented, chlorined etc.) before being sent into taps, whereas this water isn’t, that’s the difference.
The kind of thing that I am talking about - refining sewerage water and then transferring it to park and garden showers - is a fairly new technology and is being used in the Middle East because they have to desalinate water every time to use it (mind you, it’s a very expensive process). Although if we get this sewerage-used-for-gardening thing we will benefit a lot from it… I still highly doubt that we have this in Karachi, or even if we do - I doubt they work :p.