|
|
Post by Granny Smith on Mar 21, 2011 22:24:54 GMT -5
Can low-tech solution solve water crisis?Posted: 1048 GMT For millions in the developing world, water can be as dangerous as it is life saving, spreading life-threatening diseases such as diarrhoea and cholera. Every day men, women and children are forced to drink, bathe and wash clothes and utensils in fetid supplies ripe with sewage. One such slum is Kibera, part of the Kenyan capital Nairobi – but residents there hope that a low-tech solution is at hand. Locals now collect water from infected tanks, pour it into clear plastic bottles and then leave them on tin rooftops for at least six hours. Laboratory tests reveal that the sun kills dangerous disease-spreading bacteria by zapping them with UV radiation and heat through a process known as solar disinfection. An estimated two million people around the world are now using solar disinfection to draw clean water. connecttheworld.blogs.cnn.com/2009/08/31/can-low-tech-solution-solve-water-crisis/
|
|
|
|
Post by eyeofthestorm on Mar 22, 2011 8:19:29 GMT -5
This makes a lot of sense, but I'd feel a WHOLE lot better if the bottles were glass. That may not be practical, though.
|
|
|
|
Post by Valerie on Mar 22, 2011 18:18:05 GMT -5
UV is widely used in water and wastewater treatment for disinfection. It doesn't have the chemical byproducts that chlorine does, some of which cause cancer. When wastewater is chlorinated it has to then be de-chlorinated (here in the US) before discharge.
That's good that they've discovered a way to use UV low-tech, because the systems they use in treatment plants are pretty expensive (which is why many places still use chlorine).
You know that heated plastic adds chemicals to the water, though. So even though they might not get the water-borne diseases right now, they might still wind up with something down the road from the plastic chemicals.
Gayle, I'm so slow today! It just dawned on me that you posted this so we would have it for future references should we need to purify our own drinking water! I knew I collected all those gallon pickle jars for something! If someday I can't get water from our well, I can haul it home from the river a mile away and set it on the roof in pickle jars. thanks!
|
|
|
|
Post by Granny Smith on Mar 22, 2011 18:44:15 GMT -5
LOL Valerie, that IS why I posted it. I have several of those pickle jars, too, and about half a dozen half gallon canning jars. I knew they'd come in handy for more than just storing dehydrated marshmallows.
|
|
steve
Prep Cook
Posts: 236
|
Post by steve on Mar 22, 2011 23:53:01 GMT -5
Gayle I really like this. I made a water heater once by just putting a black barrel on a roof. This will definitely be going into my knowledge bank. UV purification is very popular with well water where I used to live. I can see leaving the water up maybe a couple days just to make sure. I store drinking water in used bleach bottles which I would vent for a day if I needed the water. I don't think leaving them up on a roof for a week would give you any more safety than having algae water to drink  |
|
|
|
Post by Valerie on Apr 1, 2011 6:29:53 GMT -5
I was thinking about this yesterday. I think the UV will do OK for killing bacteria but it's not enough to kill the cysts of cryptosporidium and giardia. Even chlorine doesn't kill them. For that, the water has to be boiled. Treatment plants use filters that are small enough to catch the cysts. So, if you're going to use surface water, especially that animals have access to, it would be better to set up one of those solar funnels and disinfect the water by boiling it in a big jar. If your surface water looks like ours, you'd probably want to filter it through a couple clean paint filters or something too.
|
|
|
|
Post by joanfromzone6 on Apr 1, 2011 16:16:04 GMT -5
some of our surface water could be improved by filtering it through a chain link fence -
|
|
|
|
Post by Granny Smith on Apr 1, 2011 18:21:07 GMT -5
|
|
|
|
Post by Valerie on Apr 1, 2011 19:11:43 GMT -5
I still wouldn't trust it. UV might kill the organisms, but I don't think it really would kill them when their still in the cyst form. I had to do a class on them once. They're in like a hard casing.
|
|
|
|
Post by Granny Smith on Apr 1, 2011 19:16:17 GMT -5
The college lab technician* told me that boiling won't kill cryptosporidium and you could even get it by touching the water. So how would you get rid of it? I guess you'd have to filter it out, but where would you get a filter that is fine enough?
*the college is where the Health Department sends water samples (or you can take them yourself). We had an old, open well tested. It tested positive for cryptosporidia, so that's why the technician was telling me that.
|
|
|
|
Post by Valerie on Apr 2, 2011 13:13:05 GMT -5
Those filters like they make for the GE SmartWater systems filter out the cysts. But I don't know what you'd do in a pinch. Maybe multiple thicknesses of coffee filter? I don't know all that micron size stuff. Maybe that's one of the reasons people had shorter life expectancies back in the days before modern technology.
|
|
|
|
Post by Granny Smith on Apr 2, 2011 14:25:13 GMT -5
|
|
|
|
Post by gayla on Apr 8, 2011 19:11:14 GMT -5
for a world full of water we sure have problems . just think I been keeping marshmellows in a couple of pickle jars too ..
so glad we get our water from our mountain and to us. -
|
|
