|Water and Wastewater Use in the Food Processing Industry|
|Written by North Carolina Division of Environment and Natural Resources|
|Tuesday, 06 July 2010 08:40|
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(This is Chapter 5 from the Water Efficiency Manual, available from the Alliance for Water Efficiency)
Water and Wastewater Use in the Food Processing Industry*
The following sections discuss major water using and waste generating processes in fruit, vegetable, dairy, meat, poultry, and oil processing. The information is provided to help food processing managers evaluate water use performance and consider additional water efficiency measures. In the absence of water use data, wastewater (hydraulic) loadings information is presented as a reference for water use.
Fruit and Vegetable Processing
The fresh pack segment of the industry shares unit operations with the processing segment. These operations are the sorting/trimming, washing, grading, and packing lines. But after the packing lines, additional unit operations may add to the waste generating scheme for the processing segment alone. Additional operations may include combinations of peeling, stemming, snipping, pitting, trimming, chopping, and blanching. In some instances, the final product is dehydrated (e.g., chopped onions). In others, it is packaged and processed. Processing can include one treatment or a combination of several treatments (e.g., acidifying, brining, freezing, or cooking).
Major water use and waste generation points associated with the fruit and vegetable industry include the washing steps for raw and processed produce, peeling and pitting practices, blanching, fluming the produce after blanching, sorting, and conveying the product within the plant. Reducing size, coring, slicing, dicing, pureeing, and juicing process steps, as well as filling and sanitizing activities after processing, also contribute to the wastestream.
Water Use and Wastewater Sources
Water Use and Waste Minimization
Ideally, considerable waste reduction can be achieved if harvesting equipment permits additional stems, leaves, and culled materials to remain in the field during harvest. If crop washing, grading, and trimming can occur in the field, then additional soil and food residues will remain at the farm. Realistically, most such wastes are being handled at vegetable and fruit processing plant sites. Primary waste-management strategies used by this industry are water conservation and waste-solids separation.
Water use by the vegetable and fruit processing industry is essential to the washing, heating, and cooling of food products. But the industry has adopted a number of practices, showing heightened sensitivity to the need for water conservation:
* Excerpts from "Waste Management and Utilization In Food Production and Process," CAST, October 1995.