Over the recent past, I have been reading news-reports of the people of Punjab suffering from the ill-effects of drinking polluted water. This has not only been on account of untreated industrial effluents, but also due to unprecedented amounts of chemical pesticides and fertilisers being used and ultimately seeping down into the ground water, which is a major source of drinking water in the rural areas.
Over the long term, obviously, the solution lies in getting the industrialists to set up treatment plants, so that untreated effluents do not reach drinking water sources. Additionally, chemical pesticides and fertilisers have to be gradually replaced with biotic ones.
The problem is very real, however, and requires to be dealt with in the immediate future. After all, it is now that the people who drink the water are afflicted with all sorts of diseases and genetic malformations.
Facilities like water-works are not available in the villages and are unlikely to become available over the short- to medium-term. Therefore, it is imperative that cost-effective means for purification of water by the villagers themselves be made available.
Since the impurities are well-dissolved, processes like sedimentation, decantation and filtration are, obviously, not likely to be of much help, as these are meant for removing suspended impurities only. Reverse osmosis is not only somewhat expensive and, therefore, not accessible to every one, but may also not act effectively enough on impurities originating from insecticides, even as it can remove residues of metals like lead (Pb) and mercury (Hg). An advertisement for a leading brand that I perused, stated that the product on offer 'reduces' and does not remove completely, the impurities related to insecticides. Considering the fact that such content can be quite high in the ground-water in Punjab's rural areas, the quantities that remain even after passing it through a reverse osmosis plant may still be too high for it to be safe for drinking.
Therefore, to my mind, the best alternative that remains is fractional distillation. It is important, however, that the apparatus that is made available is portable so that the villagers can use it conveniently and is made of locally available material, as far as possible, so that it can be cost-effective. Also, it should be workable with locally available fuels derived from crop waste or animal waste.
In terms of inexpensive technology, inputs may be taken from the locally developed process for the distillation of country-made liquor. That could, I am sure, serve as a starting point, at the very least.
I fervently hope that the relevant government departments or some non-governmental organisations or local entrepreneurs or corporate philanthropists can step up to the challenge at the earliest possible.