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to compare different plants. So, it is strongly recommended that an industry first determine its own environmental goals,
and after they are reached, compare theirs to others, from other plants, or other countries.
In Table 1, we enumerate benchmarks in three countries that relate to the level of technology used. The traditional
technology is generally used in medium to large abattoirs with low utilization of installed capacity and no cleaner
production, it is typically used in developing countries. The average technology is used in large slaughterhouses with
minimal cleaner production methods and is common in many Western countries. The Best Available Technology (BAT)
approach is used in industrial slaughterhouses with good utilization of the installed capacity, high throughput and good
practices in all segments. In the late 80´s, for each slaughtered pig, an average European slaughterhouse needed 140 L of
cooling water, 310 L of process water and 10 L of process water for steam production, resulting in a total 460 L/pig. In the
meantime the process water use has been halved (230 L/pig) due to good housekeeping and the high level of reuse of
cooling water (Stoop, 1999).
In order to harmonize the environment with the economical requirements and to achieve a sustainable development
national and local policies must be established. In Brazil, through the Federal Law n
o
9433 (Brazil, 1997a) the National
Policy of the Water Resources was sanctioned, and water was recognized as a limited and valuable natural resource,
which must be managed by economic instruments as taxation and conveyance. The amount of water taken out from a river
or the wastewater to be put in it, results in more taxation, this aspect favors the conservation and the reuse of the water.
Recently, the National Council of Water Resources issued the first national regulation concerning the thematic of reuse of
non-potable water, the Resolution nº 54 (Brazil, 2005), establishing modes, criteria and directions to its use. It must also
be emphasized that the environmental regulations/legislation concerning the discharge of effluents are becoming
increasingly stringent, and often implicating in elevated investments from the industries to achieve the established
standards. In order to minimize costs, impacts and wastefulness of this scarce resource, the reutilization of water supply
became mandatory, in all sectors of our society.
The water consumption in the food industry is intense due to strict sanitary regulations and usually excessive, mainly
because the personnel do not take care on how much water they are using and the cost of it, as for environmental impacts
generated (Codex Alimentarius, 2001). In Brazil, the law that deals with sanitary requirements to animal products is the nº
30691 (Brazil, 1952) and in its paragraph 62 establishes standards to the water used in meat processing plants. In recent
years the “Technical guidelines to the sanitary and hygienic conditions and to the good practices to food preparation
industry” was approved trough the Statute nº 368 (Brazil, 1997c) and Statute n
o
326 (Brazil, 1997b). These regulations
main purpose was to establish the use of drinking water in most of the procedures, drinking water defined as described in
Regulation n
o
518 (Brazil, 2004). The “Technical guidelines to the sanitary and hygienic conditions and to the good
practices to food preparation industry” incorporate the requirements of the "Proposed draft guidelines for the hygienic
reuse of processing water in food plants" (Codex Alimentarius, 2001). This guideline establishes that reclaimed and
reused wastewater may replace potable water, under carefully considered circumstances where public health will not be
compromised. Also it anticipates that water reuse practices should include, but would not necessarily be limited to: the
washing of product; the movement of product; the cleaning of equipment and food processing facilities (including floors,
walls and ceilings); and the generation of steam for multiple purposes including indirect contact with product. According
to these guidelines the water quality to be reused in food processing must be in accordance with the proposed objectives
and the major concern is the uncertainty about the control of pathogenic microorganisms and their potential health effects
(Levine and Asano, 2002). Application of a hazard analysis critical control point (HACCP) to water reuse in food industry
is indicated (Casani and Knochel, 2002; Casani, et al., 2005; Casani et al., 2006).
This work was developed in a pig slaughterhouse, which process 1150 animals/day and also undertakes the further
processing of meat products and by-products. Its initial goal was to evaluate its water consumption, by identifying the
main pathways and quantifying the volume of water used in each one and estimates an index (benchmark) for that specific
process. After that, by comparison with data obtained from Cleaner Practices and BAT reference documents, as well as
data from similar industries, we try to demonstrate the possibility of water consumption minimization. As an initial target
of optimization, a study of the implementation of a simple procedure to minimize the water use and pollution charge
generated in the holding pens was done. In order to evaluate the quality and adequacy of the treated effluent for reuse at
the industrial process, its main physical, chemical and biological parameters were analyzed.
This paper may contribute in the reduction of water consumption, towards cleaner production and in the pathway to
sustainable development in the industry process, as endorsed by Agenda 21, observing the legal and sanitary requirements
for an industry in operation.
1.2. Site and process overview
The industry is situated at the municipality of Frederico Westphalen, in the northwest part of Rio Grande do Sul State,
Southern Brazil (Latitude S 27°21'06.3" e Longitude W 53º23'42.2"), as shown in Fig. 1.
The basic process for slaughtering and processing pigs is shown in Fig. 2, following these steps:
1. Pre-handling of pigs – Pigs are delivered to the abattoir in trucks and held for some hours in holding yards where
they are fasted to reduce the amount of intestinal contents.
2. Stunning and bleeding – Pigs are stunned using an electric shock, after which they are bleed. Bleeding is carried out
using a knife, which directs the blood to a collection trough, from where it is pumped to a tank for further processing.