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SOURCE OF ENGINEER

Water Pre-treatment

Process in Food Industry

A successful food and beverage processing operation
needs a stable high water quality supply and the
appropriate treatment of wastewater. On many
occasions the finished product is not just a result of
the raw material, but caused by changes in feed water
quality. Besides water quality, the most important “Water reuse
requirement is reasonable cost for the feed water. There within industry can
are several fresh water sources, which are chosen upon be fully exploited,
several factors. The most appropriate action is as less except for food and
treatment as possible. The regulations are stringent pharmaceutical
and defined in detail. The objective of this review is to
provide a brief explanation of the water pre-treatment applications.”
methods available in food processing.

Safe water and hygienic sanitation coverage is still low, especially in
rural areas. Fresh water resources, especially those of high quality, are formed, not only in water but also on equipment, vessels, pipes and
becoming scarce because of population growth and urbanisation. The fixtures. A common treatment is ion exchange and the use of iron filters,
availability of good quality water and in high quantities is vital for food mostly filled with catalytic materials, which are very efficient for iron and
safety and production. Water can contaminate food: protozoa, viruses manganese removal, and require fewer chemicals for regeneration.
and in some cases even pathogens may be spread from contaminated Reverse osmosis equipment can remove taste, colour and odour
water to the food. Such water is not potable and drinking or using such from water. It can remove all known micro-organisms and most other
water in food preparation might lead to widespread acute and chronic health contaminants. The reverse osmosis unit is shown in the Figure 1.
illness. Membrane processes are characterised by the fact that the feed
Water influences the structure and taste of food and its receptiveness stream is divided into two streams: into the retentate or concentrate,
to spoilage. In any case, the presence of organic matter, colour, taste, and the permeate one. In all membrane processes separation is
and odour is unacceptable in water to be used in food and beverage achieved by a membrane, which can be considered as a permselective
processing operations, and must be removed. barrier existing between two homogeneous phases.

Pre-treatment Processes Disinfection
It is necessary to create water pre-treatment coupled with the principles The easiest way to destroy micro-organisms is to add chlorine solution,
of a single method, in order to enhance aesthetic acceptability, and the lower concentration is used in a product to prevent off flavours. A less
removal of toxic or health-hazard materials. Detailed description and suitable method is pasteurization, especially because of processing
advances are described in the following chapters. costs (high fuel requirements). Very powerful disinfection is achieved
by using ozone. The described processes, recommendations for use
Removal of Organic Matter and removal of contaminants are gathered in the Table 1. Whilst
The most widely used systems are the conventional methods, such as the economic benefits are the central point of management, more
precipitation, coagulation and flocculation, sedimentation and filtration. emphasize should be given to equally consider the environmental and
Dispersed, suspended, and colloidal particles producing turbidity and social aspects in future decision- making processes. Long time ago
water colour, cannot be removed sufficiently by the normal sedimentation some authors pointed out that economic benefits are significant for
process. Adding a coagulant, mixing, and stirring the water cause the companies which are looking for more effective solutions to pollution
formation of settleable particles. These flocks are large enough to through conservation-oriented technologies by reducing water use
settle rapidly under the influence of gravity, and may be removed from and waste generation, because in food plants pollution prevention is
suspension by filtration. more economical than pre-treatment.

Colour, Odour, and Taste Removal
When iron or manganese is present in water, both metals are oxidized เอกสารอ้างอิง/Reference
(by dissolved oxygen) and, consequently, coloured precipitates are Marjana sIMoNI. Water pre-treatment process in food industry. International
Journal of sanitary engineering research Sanitary Engineering Research.
Vol. 3. No. 2/2009
62 FOOD FOCUS THAILAND JUL 2018