Integrierte Vermeidung und Verminderung der Umweltverschmutzung

Chapter 2
The treatment required to produce safe water quality depends very much on the water source
and its analysis. There is no general rule. A minimum treatment concept involves water
filtering, disinfecting and storage, but depending on the water requirements, may also include
de-ironing, desilication, or active carbon filtering. Treated drinking water is pumped from the
storage tank and distributed through the installation pipework network to the users.
Additional treatment, such as softening, dealkalising, demineralising or chlorinating the water,
is needed for usage in specific food processes or utilities. Ion exchangers or membrane filtration
processes are the most common techniques used for this purpose.
Water pollution control can be carried out by reducing the volume and strength of waste water
generated, by in-process techniques such as eliminating or decreasing the concentration of
certain pollutants, e.g. dangerous and priority hazardous substances; recycling or re-using water
or end-of-pipe techniques, i.e. waste water treatment, or a combination of these.
The following sources of water are used in the FDM sector: tap water, groundwater, surface
water, rainwater, water originating from the raw material and process water.
Tap water is distributed by a water main. The supplier is usually responsible for the quality of
the water delivered and for checking the quality of the water regularly.
The composition of groundwater is generally reasonably constant and microbiological counts
are mostly low, especially in deep bore holes. In most cases, little treatment is necessary before
groundwater can be used as process water or cooling water. In most countries, a licence is
needed for the extraction of groundwater. The quality of the groundwater is monitored by the
user. Sometimes the authorities require notification of the results of regular water quality
analyses.
Surface water cannot be used for process water unless it is treated first. When available, it is
often used for cooling water. A licence may be required for such use.
Depending on the region, rainwater may be a source of water. This requires a storage basin.
After appropriate treatment and control, rainwater may be used for process water, in open
cooling systems.
Some raw materials that are processed in the FDM sector contain a considerable percentage of
water as a liquid water phase, which can be separated from the solid constituents for separate
utilisation. This separation can be carried out, e.g. by pressing, centrifuging, evaporation or by
using membrane techniques. Some examples are fruit juice, potato juice, sugar beet juice and
milk. Such liquids can mostly be utilised if they are not used as a primary product. Sometimes
they can be used without further treatment, e.g. condensate of the first stages of evaporators for
boiler feed-water, but otherwise appropriate treatment is necessary.
Process waters may be used from, e.g. chiller water, pump seal water, recovered condensate,
final cleaning rinses.
2.1.9.3.2 Field of application
Water is used in the FDM sector for:
• food processing, where the water either comes into contact with, or is added to, the product
• equipment cleaning
• installation cleaning
• washing of raw materials
• water which does not come into contact with the product, e.g. boilers, cooling circuits,
refrigeration, chillers, air conditioning and heating
• fire fighting.
In principle, the water used in the FDM sector may be used as process water, cooling water or
boiler feed-water. These are described in Sections 2.1.9.3.3, 2.1.9.3.4 and 2.1.9.3.5.
54 January 2006 RHC/EIPPCB/FDM_BREF_FINAL