Safe Drinking Water Development, New Ideas

Calculation will work for chlorine; if the concentration of the calcium or sodium hypochlorite solid is known, possibly by measuring its weight on a simple scale and relating it to a known volume upon dilution, then it becomes possible to work out the dilution effect of adding a known quantity of solution into a larger known quantity of water.

Sand filters just work, and they can be really low-tech.

The WaterAid website really needs to be in the "favourites" box for all readers interested in this topic. WaterAid has an active interest in installing low-tech water supply and sanitation systems across the globe, though it is most active in the developing parts of Africa.

This is a good topic for sharing discussions. More power to your elbow!

Yes Calculation will get you close. It is easy enough to then test for residual chlorine. Speaking of sand filters. Beleive it or not there are many places where you cannot get good quality sand. Here at my home you just stop at the local building supply. Quarried sand is best because of size and shape.

The rough edges make it good for trapping and slowing the flow. River and lake sand normally has more rounded edges. Calcined clay will also work. I have experimented with calcined clay and calcined slate with good results. A small rotary kiln in Kenya would be very benifical. They are firing laterite in South Africa for filter use to remove fluorides. Too much fluoride will cause bone embrittlement.

Here is a sodium hypochlorite generator I built. 1 pound of salt, five gallons of water and some DC current. Run it for a few hours and there is enough available chlorine to disinfect 25,000 gallons of water

<some DC current. Run it for a few hours and there is enough available chlorine to disinfect 25,000 gallons of water>

Bucket chemistry - wonderful! This sort of thing will respond to calculation too, as one knows the current and the time, so one knows the chlorine level.

This sort of thing is good for off-the-grid applications, as it could be powered by wind or solar. Or a Land Rover battery.

Yes DC power can be easily obtained and stored. I need to spend some more time looking into that. There are some new developments in solar cells. I still need to do a cost analysis between buying calcium hypochlorite and producing sodium hypochlorite with off grid energy. Then there is always the maintanance issue of equipment. Just trying to keep it simple.

Though this is a relatively easy means of chlorine production in the field, you're left with an environmentally unfriendly solution of strongly alkaline, very corrosive, toxic to fish and rivers, solution of sodium hydroxide to dispose of.

So I suppose that you could bubble enough CO₂ entrained air (Like vehicle exhaust) through it to convert it to baking soda.

You can collect the Cl at one end, for sanitation, and the H at the other to power a generator to charge the batteries adjacent. Might get enough to run your laptop.

Don't forget to cool the exhaust enough to salvage the water from the exhaust.

Also be very careful with the hydrogen gas. When burning in air, the flame emits only ultraviolet light, and is invisible to the human eye.

So a sction of quartz pipe by the hydrogen burner could be used to sterilize your water at the same time.

OK, no problems left.

RichH

Not so! check out your chemistry. With this process the sodium chloride separates into sodium hydroxide and chlorine. As the hydrogen is dispersed the sodium hydroxide and chlorine recombine into sodium hypochlorite. I am not using the membranes to make chlorine gas. I am making 0.8% sodium hypochlorite solution. Clorox is a little over 3%. The only byproduct is hydorgen.