Page 34 - Chemical Technology

water treatment
32 Chemical Technology • January 2013
water per litre of beer in the Czech Republic. The 110 litres
of water per litre of beer difference is due to crop cultiva-
tion. In particular, the South African farmers are more
reliant on irrigation using blue water. This, combined with
the high rate of evaporation in South Africa, accounted for
a much higher rate of consumption in South Africa.
These water footprints need to be reviewed in the
context of other factors, for example, with economic
and social impacts, to help gain a more comprehensive
picture (Hastings and Pegram, 2012).
Water Footprint of a cup of coffee
The water footprint of a cup of coffee is 208 litres
(Chapagain, 2010). The figure above shows the dif-
ferent components that make up a cup of coffee and
its water footprint distribution. The raw coffee beans
contribute the largest component at 142,8 litres. This
large amount is associated with the planting, irrigation,
harvesting, and processing of the beans (Hastings and
Pegram, 2012).
Water Footprint of Coca-Cola
The Coca-Cola Company, in partnership with The Nature
Conservancy, carried out a Water Footprint Assessment
on various products. These included:
• A 0,5 litre PET(polyethylene terephthalate) packaged
bottle of Coca-Cola; and
• Sugar produced in different European countries.
The assessment covered the bottle supply chain
processes to understand the risks and dependencies on
water for the 0,5 litre PET packaging bottle. The direct
and indirect water used in the packaging manufacturing
process, the Coca-Cola drink manufacturing process,
and the direct water used in the bottling manufacturing
process were examined (Hastings and Pegram, 2012).
The total water footprint of a 0,5 litre PET bottle was
calculated to be 35 litres (see Figure 4).
This comprised 8 litres of blue water, 15 litres of
green water, and 12 litres of grey water. Both the blue
and green water footprints were associated with the
sugar production. The grey water footprint was associ-
ated with water consumption in the cooling activities
of bottle manufacturing and water consumption in the
production of the fertilizer used in sugar beet farming.
Figure 3: Water footprint of a cup of coffee (Hastings and Pegram,
2012)