Page 190 - Membranes for Industrial Wastewater Recovery and Re-Use

Industrial waters 159

3.4 The beverage industry
The food and beverage industries are major consumers of water, with the
beverage industry in particular consuming as much as 10-12 tonnes of water
per tonne of product - or even more for brewing. The majority of water consumed
in this industry is used in washing and cleaning operations, and as such
represents significant opportunities for reclaim and recycling. Global water
usage within the two sectors is difficult to define, but some available data for
beverage production (Table 3.35) suggest global usage of around two billion (i.e.
thousand million) tonnes of water per annum. The food industry in the USA
alone consumes 4 billion tonnes of water per annum - 50% more than the
second largest user, the pulp and paper industry (Levine and Asano, 2002).
The food and beverage industries do not generally reuse or recycle water
which is either used in or comes into contact with the product. This is primarily a
marketing and public perception issue in the same way as recycling of sewage
effluent for potable water has significant consumer acceptance problems (Section
1.1). Since a significant amount of water in the industry does not go into the
product, opportunities still exist for water reuse and the quality of water required
for use in the product is not normally of concern for recycling. However, the
water quality demanded for washing the product or product containers purposes
is usually of potable standard, and there is still a reluctance to use recycled water
even for these duties. Recycled water must be either recycled at the point of use to
avoid additional contamination or recycled to non-product uses, such as utilities
(usually power generation and heat transfer) and washing. Fortunately, because
food, dairy and, in particular, brewing processes are energy intensive, the utility
water consumption in boilers and coolers is quite high and can demand up to
twice as much water as the primary production process.

3.4.1 Point of use recycling opportunities

Bottle washers
In the dairy and beverage industries the bottle washer is a significant user of
water, and most washers have a make-up water flow rate to the final rinse
of about 10-20 m3 h-l (which equates to 250 ml per bottle). A proportion of
this water is used to pre-rinse the bottles but a significant part of this final rinse
water is discharged to drain. The water is generally low in turbidity with a pH of
about 10.5 and a conductivity of about 2 500 pS cm-l.

Table 3.35 Global water use, beverage industry
Volume. m3 p.a Global water use. m3 p.a. Average weight ratio
Soft 380 000 000 1140000000 3
drinks
Breweries 136 000 000 952 000 000 7