Conservative Use of Chemicals

Many textile mills use excessive and even unnecessary chemicals. Often chemicals are added to a dye recipe to counteract a negative side effect of another ingredient instead of finding a substitute for the offending chemical. This approach can result in a series of unnecessary chemical additions which negatively affect effluent quality and processing costs. All processing recipes should be reviewed and reduced to their original base state. If a problem arises from the base state, then chemical substitutions should be considered in lieu of chemical additions [6]. As stated by Smith in reference [28], a good example of chemical specialty misuse is frequently seen with chemical specialty leveling agents and retarders. These are used with a wide variety of dye types (e.g. acid, basic, direct, disperse) to ensure even and level dye exhaustion on the substrate. According to this author, the same level exhaust can be obtained by proper temperature control. Smith also stated that the use of chemical specialty retarders and levelers usually results in lower ultimate dyebath exhaustion, thus more color in the wastewater.

According to reference [10], it is possible to lower the pollution problems by reducing the chemical loads, since very often a large margin of safety is employed. A careful study of the various textile processes, with respect to the minimum requirements of different chemical recipes can reduce the amount of process chemicals by 20-50% and the effluent load in terms of BOD by about 30-50% with the obvious associated benefit of lower operating costs.