PB85-116143 Dyebath Reuse Saves Money and Reduces Pollution Sverdrup and Parcel and Associates, Inc. St. Louis, MO Prepared for industrial Environmental Research Lab. Research Triangle Park, NC Oct 84 [ mmm IW'TM 1 U.S. Department of Commerce National Technicai Information Service NTIS » ------- PB85-116 la3 EPA-600/M-84-002 October 1984 DYEBATH REUSE SAVES MONEY AND REDUCES POLLUTION Jon Bergentha1 - Project Manager Sverdrup & Parcel and Associates St. Louis, Missouri John Eapen - Corporate Environmental Manager Bigelow Sanford, Inc. Greenville, South Carolina Anthony Tawa - Project Engineer Sverdrup & Parcel and Associates St. Louis, Missouri Dr. Wayne Tincher - Professor Georgia Institute of Technology Atlanta, Georgia EPA Contract 68-02-3678 EPA Project Officer INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY OFFICE OF RESEARCH AND DEVELOPMENT U.S. ENVIRONMENTAL PROTECTION AGENCY RESEARCH TRIANGLE PARK, NC 27711 by Robert V. Hendriks 'b^y &egion aV REPRODUCED BY NATIONAL TECHNICAL INFORMATION SERVICE US DEPARTMENT OF COMMERCE SPRINGFIELD, VA 22161 ------- TECHNICAL REPORT DATA (Ph ase read Irninu Huns on the rci crsi bejore completing) l REPORT NO 2 EPA-600/M-34-002 3 RECIPIENT'S ACCESSION NO PB8 5 1 1 614 3 J TITLE and SUBTITLE Dyebath Reuse Saves Money and Reduces Pollution 5 REPORT OATE October 1984 6 PERFORMING ORGANIZATION CODE 7 authorisi Bergenthal, J.Eapen (Bigelow Sanford, Inc.), A.Tawa, and W. Tincher (Georgia Tech) 3 PERFORMING ORGANIZATION REPORT NO 9 PERFORMING OROANIZATION NAME ANO ADDRESS Sverdrup and Parcel and Associates, Inc. 801 North Eleventh St. Louis, Missouri 63lO 1 10 PHOGRAM ELEMENT NO 11 CONTRACT/GRANT NO 68-02-3678 12 SPONSORING AGENCY NAME AND AOORESS EPA, Office of Research and Development Industrial Environmental Research Laboratory Research Triangle Park, NC 27711 13 TYPE OF RETORT AND PERiOD COVERED Journal article; 4/81-12'83 14. SPONSORING AGENCY CODE EPA/600/13 15 supplementary notes IERL-RTP project officer is Robert V. Hendriks, MD-63, 919/ 541-3928. i6 AB-TRACTxhe article discusses an evaluation of the potential for wastewater recycle or reuse in textile finishing mills. Over a dozen recycle technologies were evaluated in six separate mills. Results of these preliminary studies showed that most of the recycle technologies were technically feasible, but only a few were cost effective: synthetic size recovery and reuse, caustic recovery and reuse, direct wastewater reuse (e.g., countercurrent washing), and direct dyebath reuse. The last-mentioned was singled out for further study because it was seen as having several advantages: low capital cost for implementation, substantial processing cost savings, significant environmental benefits, and the potential for widespread use in the industry. It is estimated that about half of all textile dyeing is performed by batch operations, inclu- ding most knit fabric, hosiery, and yarn, along with substantial amounts of carpet and some woven fabric. Dyebath reuse technology was first developed by the Georgia Institute of Technology about 10 years ago, but few mills have adopted it to date. 17. KEY WOROS AND DOCUMENT ANALYSIS a DESCRIPTORS b IDE NT IF 16 RS/OPEN ENDEDTERMS c COSATi 1 idd/Croup Pollution Textile Finishing Dyeing Waste Water Water Treatment Circulation Pollution Control Stationary Sources Dyebath s Recycling 13B 13H 14G distribution statement Release to Public 19 SECURITY CLASS (This Report) Unclassified 21 NO OF PAGES 8 20 SECURITY CLASS (This page) Unclassified 22. PRICE EPA Form 2220-1 (9-73) 1 ------- NOTICE This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication. Mention of trade names or commercial products does not constitute endorse- ment or recommendation for use. ii ------- Between 1981 and 1983, the U.S. Environmental Protection Agency sponsored a project to evaluate the potential for wastewater recycle or reuse in textile finishing mills. Over a dozen recycle technologies were evaluated at six separate mills. The results of these preliminary studies showed that most of the recycle technologies were technically feasible, but only a few were cost effective: synthetic size recovery and reuse, caustic recovery and reuse, direct wastewater reuse (e.g., countercurrent washing), and direct dyebath reuse. Direct dyebath reuse was singled out for further study under the EPA Project. It was seen as having several advantages: low capital cost for implementation, substantial processing cost savings, signifi- cant environmental benefits, and the potential for widespread use in the industry. It is estimated that about half of all textile dyeing is performed by batch operations, including most knit fabric, hosiery, and yarn, along with substantial amounts of carpet and some woven fabric. Dyebath reuse technology was first developed by the Georgia Institute of Technology about ten years ago, but few mills have adopted it to date. EXPERIMENTS AT BIGELOW-SANFORD A series of dyebath reuse experiments was conducted during the summer of 1983 at Bigelow's laboratories in Greenville, South Carolina. Two grades of nylon carpet along with six shades for each grade were selected for these bench-scale experiments. Five batches of each shade were dyed from the same bath and the shade matching results checked. Further tests were done in which the batches dyed from the same bath gradually progressed from light to dark shades. The tests showed that successful shade matching could be achieved with dyebath reuse. Much valuable experience was gained in these experiments with the techniques needed to analyze an exhausted dyebath and reconstitute it for the next dyeing. The only special equipment required was a simple visible-light spectrophotometer, calculator and some laboratory glassware. A desk-top (home) computer was used later instead of a calculator to simplify and automate the dyebath analysis procedure. 1 ------- Following these initial experiments, several pilot-scale dyeings were performed to verify the results of the bench-scale experiments. Shade matching and color fastness tests were again satisfactory. FULL-SCALE DEMONSTRATION A week-long plant demonstration of dyebath reuse was conducted at Bigelow's Summerville, Georgia plant. A temporary pump and piping arrangement was set up for the demonstration. At the end of a dyeing, the exhausted dyebath was pumped to an adjacent beck already loaded with carpet fo^ the next dyeing. The dyed carpet in the first beck was rinsed and pulled in the normal fashion. Meanwhile, a sample of the exhausted dyebath was analyzed and the compu- ter quickly printed out the amounts of dyes and chemicals to add for the next dyeing. The same two grades of nylon carpet that were used in the bench- and pilot-scale experiments plus some additional shades from these carpet grades were selected for the full-scale dyeings. As many as ten batches were dyed with the same dyebath during this demonstration. All the dyeings were first quality, and were done without any adds or redyes above normal requirements. The amounts of water, dyes, chemicals, and steam used in the dyeings were carefully recorded. The savings for a typical dye cycle are shown in Table 1. Based on these savings, a yearly savings of $30,000 is projected for each beck on which dyebath reuse is installed. COSTS The capital cost for permanently installing dyebath reuse at two of the plant's dyebecks is about $80,000. This includes a pump; a 6,000 gallon dyebath storage tank; associated piping, valves and controls', and the dyebath analysis equipment noted above. 2 ------- Yearly opeiating costs are estimated to be $5,000, with yearly savings of $60,000 for two becks. This results in a payback period of about 1 years. The prospects for reducing the payback period even further are good. Many areas exist for optimizing th>? dyebath reuse process, thereby increasing the chemical and energy savings. ENVIRONMENTAL BENEFITS Samples of dyeing wastewater were taken from both conventional dyeings and reuse dyeings. The samples were compared, and the results are shown in Table 2. Not only does dyebath reuse result in cost savings from water, chemical, and energy savings, but it also reduces the amount of wastewater and pollutants discharged. Dyebath reuse, along with other types cf wastewater recycle, can be a more cost-effective approach to reducing pollution than waste treatment. USERS MANUAL A manual describing the concepts and procedures for reusing dyebaths was produced as part of this project. With this manual, a textile mill can evaluate and test dyebath reuse on ]ts own. Detailed descriptions of needed equipment items and their use are given, and a computer program for dyebath reuse is presented. The detailed results of the studies at Bigelow-Sanford are also included in a separate volume. Both volumes of the report are available from NTIS. Footnote: Although this project was funded in part by the U.S. Environmental Protection Agency under contract number 68-02-3678, this article has not been subjected to the Agency's peer review and therefore no official Agency view or endorsement should be inferred. 3 ------- TABLE 1 DYEBATH REUSE COST SAVINGS Cost Savings Item Pollars/Cycle vs. Conventional Dyeing Dyes $ 0.03 1% Chemicals 18.58 35% Water/Sewer 4.70 36% Energv 5.33 <10% TOTAL $28.64 per cycle 4 ------- TABLE 2 ENVIRONMENTAL BENEFITS OF DYEBATH REUSE Pollutant Flow BOD COD Dissolved Solids Reduction in Discharge From Dyebath Reuse 34% 33% 33% 43% 5 ------- 1021477 O-'&tety DATE DUE ------- |