The business of
safe water
Disinfection and the challenge of old infrastructure rears its ugly head.
By Mike Muller
T
products like petrol for foreign exchange.
We could get lime locally, but aluminium
sulphate and chlorine were imported.
Although some people complain about
its taste, chlorine is one of the world’s
wonder drugs. It has saved more lives
than almost all medicines. I discovered
that in Beira when we ran out for a
couple of weeks and the number of
patients at local clinics immediately
increased.
“Is there something we could do
about this?” I asked the UK-based
Intermediate Technology Development
Group, founded by the famous ‘small is
beautiful’ professor Fritz Schumacher.
Specifically, could we produce chlorine
locally?
Being by the sea, we had mountains
of salt available (for readers who failed
chemistry, salt – or sodium chloride is the
raw material for producing caustic-soda
with chlorine as a by-product). We had
electricity from the hydropower plants
on the Buzi river. Was there a chlorine
generator for water treatment in poor
countries? If not, could we develop a
robust piece of equipment to electrolyse
a salt solution and produce disinfection-
strength sodium hypochlorite?
ITDG found a chemical engineer who
confirmed that it was indeed possible.
he recent cyclone Idai disaster
in Mozambique reminded me
of another life, when I ran the
water supply of Beira. Contrary
to media reports, Beira wasn’t the worst
affected by the cyclone – that was the
dubious privilege of the small town of
Buzi on the other side of a rather wide
estuary.
Beira’s water supply was restored
within a few days of the cyclone when
the power lines were put back up. But
it was always a challenge to keep the
city’s water running and safe, not least
because important things like chemicals
for water treatment competed with
Seawater, with its natural supply of
sodium chloride, is the raw material
capable of producing caustic soda with
chlorine as a by-product.
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Water Sewage & Effluent May/June 2019
www.waterafrica.co.za