The major pollution problems presented by textile wet processing are water pollution problems. There are a few problems with air pollution by chemicals, lint, etc, but these are minor . The largest impact, especially with respect to water pollution, may be made in the wet-processing operations, primarily those steps taken after the construction of unfinished fabric (commonly called gray or greige goods), because these operations are the most water and energy-intensive and potentially the greatest waste-generating part of the textile industry .
Because there is such a diverse product and application range of textiles today, the type of processing used is highly variable and depends on site-specific manufacturing practices as well as the type of fiber used and the final physical and chemical properties desired. Even for a constant product type, no two textile mills use exactly the same methods of production .
The information contained in the tables, describing in more detail the characteristics of the textile industry categories, must not be considered a material balance. It is just a compilation of the data found in the literature reviewed. They are presented just to give an idea of what the order of magnitude of the different inputs and outputs can be. Due to the variety of process and bibliographic sources used, the data might not be consistent (i.e., the sum of individual data with respect to global data or even the values for water consumption and water discharge from an operation might present important differences).
In the literature reviewed, dyeing and printing are described as a unit operation and differences between processing operations were not specifically found. Therefore, these two operations are described under a separate heading rather than as a step in a particular industrial category.