||Sverdrup and Parcel and Associates, Inc., St. Louis, MO. ;Georgia Inst. of Tech., Atlanta. ;Bigelow-Sanford, Inc., Greenville, SC.;Industrial Environmental Research Lab., Research Triangle Park, NC.
The paper discusses the recent demonstration of the application of an important wastewater recycle technology (reconstitution and reuse of spent dyebath solutions) to the textile industry. After several months of bench and pilot testing, the technology was demonstrated under production conditions for 2 weeks at a major carpet mill in the Southeast. Of the 13 batch production units (becks), 2 were used in the demonstration. The project showed how several technical problems, encountered using dyebath reconstitution at a wide variety of textile mills, could be overcome, including: selecting product styles and shades that can be incorporated in a dyebath reuse scheme; reformulating dye recipes to use a single group of dyestuffs to dye many shades; reusing dyebath on a portion of production within the normal production schedule; producing high-quality product with recycled dyebaths; and adapting dyebath reuse procedures to the mill's standard dyeing procedures. The environmental benefits to the mill were significant, even though dyebath reuse was not practiced optimally: pollutant and water use were reduced 25-50%; dyebath reuse was shown to be economically attractive, with an 18-month payback projected for the mill; and a capital investment of $240,000 and a yearly operating cost of $5,000 could save $180,000 per year if half of the mill's becks were converted to reuse.