Thursday, 27 August 2015

Drinking Water Production in Gajner, Rajasthan

Considering that all interns in the house have had stomach issues at least once during our internship, I started a research about the drinking water treatment possibilities and needs we might have.

At the beginning of July I went to see Jeetendra, a doctor in Gajner’s hospital. He told me there were many patients showing different sicknesses related to the drinking water in Gajner, such as typhoid fever or diarrhea and pain caused by bacteria such as E. Coli. This fact suggested that the water we were consuming was not safe. We have a filter in the house but it was clearly not enough.

Considering the weather in Gajner, disinfection of the water through Ultra Violet (UV) radiation seemed to be a good way to proceed, followed by adsorption onto activated carbon (AC). So, at the beginning of August, when my water conservation project was more or less running without too much supervision, I started with the construction of the drinking water system.

UV radiation is present in the energy of the sun, and is capable of interfering in the DNA chains of bacteria and viruses, causing their death. Moreover, UV radiation also reacts with the oxygen present in the water generating free radicals and hydrogen peroxide, both of them able to destroy pathogens and contributing to disinfection.

Furthermore, high temperatures are a limiting factor for the survival and development of pathogens in the water. The temperatures reached making use of this method are not high enough to exceed the limits for all pathogens to die (reached for instance when we boil water), but both factors together are responsible for the ability to get a water with high quality.

As for the AC, I consider myself a big fan. Its huge surface area allows the accumulation of a large number of contaminant molecules and ions. As an example, one gram of a typical commercial AC has a surface area equivalent to 1,000 square meters. So once we couple both processes together, the quality of the drinking water should be very high.

I had a glass box constructed, with a capability of 25 L. The height of the box is 7 cm (it must be less than 10 cm in order to ensure that the radiation reaches the lower layers). The glass needed to be very thick, so for the cover I used a thinner glass which allowed better for the solar radiation to pass through. The glass box was connected to the water tank (see figure A) and situated above an aluminum sheet so as to reach higher temperatures. The outlet of the box is connected to two activated carbon filters (see B and C).

Figure A: The water tank connected
 to the glass tank
Figure B: Glass tank connected to
carbon filters 
Figure C: Front view of the drinking
 water production system 

The cleaning method consists on filling the glass box through the tap connected to the water tank. After, the water must be left in the glass box under the sun for a period of time of six hours. Then, we can open the outlets of the glass box and collect the water when it comes out of the carbon filters.

The carpenter of Gajner, who helped me with the installation, wants to set up the same system in his house, which makes me feel very proud; but first I would like to make sure that the water is safe. For this matter, I contacted a Professor of the faculty of Environmental Science of the University of Bikaner in order to ask him if I could carry on some lab analyses to measure the degree of disinfection and other parameters for my water conservation project. He does not seem to be very interested in my story though. Still, I will go this week with some water samples to the university and let’s see if someone allows me to play in the lab.

Lucía Villamayor - Spain 
Bikaner Cluster Coordinator, Gajner


  1. Great job Lucía!! Keep trying, someone smart with a laboratory must be over there!!

  2. You rock, Lucía!
    Go Girl!