POSITIVE ENVIRONMENTAL MANAGEMENT VIA WASTE MINIMISATION IN A TEXTILE WASHING FACILITY Samudrika Wijayapala M.Phil - April 2000 University of Moratuwa Sri Lanka. e®«go Serf© 8£B,@ca. § & _ 72218 T h This dissertation has not been previously prepared in whole or part to any University or Institution for a higher Degree. Acknowledgement I acknowledge with gratitude the General Manager and the management of the Garment Washing Factory, specially the Dye House Manager, Mr.Sisil Dharmapriya and the Shift Engineer Mr. Lakmal Perera in giving me the opportunity to carryout this project at their production facility at Ratmalana. I am grateful to Dr. Ajith de Alwis and Mr. N.G.H.de Silva, my co-supervisors who very generously spared their precious time and provided necessary guidance and assistance to carryout this difficult task. I also extend my gratitude and thanks to Prof. Lakdas D. Fernando, Head of the Department, Textile and Clothing Technology, University of Moratuwa for providing me with all necessary assistance in carrying out this project. Further I wish to sincerely thank the staff of the Departments of Chemical Engineering, & Civil Engineering of the University of Moratuwa as well as the other Textiles and Garment factories and the Mr. Sena V. Peiris, The Chairman, Project SMED, who helped me in various ways to complete my project successfully. I am also thankful to the members of the academic and non-academic staff of the Department and especially the Technical Officer P. Wanniarachchi and Mr. W. Chandradasa for the assistance extended to me. in Summary Textile and garment Industry is an important industry sector in the Sri Lankan economy. The finishing part comprises the final step in textile processing and it is known as a sector with high polluting potential. In the textile washing sector considerable quantities of water is used only once usually and is discharged without any recovery. To stay competitive this industry needs to be modernised and definitely needs better performance in the environmental management sector. This project was limited to looking at the environmental management aspects and that too with only a single pollutant stream -water. The sector of the textile industry considered is the textile washing industry. A garment washing plant is analysed with the objective of promoting water recycling and waste minimization practices. Initially typical practices were reported, followed by a water balance for the system . Results of the water audit presented here forms the first essential element of the waste minimization process. Water stream is considered from the inlet to the exit, and the consideration is given to methods of conservation possible of this valuable natural resource while obtaining the optimal use in the process. The time that water was assumed to be a limitless low-cost resource has already passed. Today there is an increasing awareness of the danger to the environment caused by over-extraction and use of water. There is now considerable incentive to reduce both consumption and wastewater production. The selection of the washing industry was selected for this study under that consideration. This industry sector today uses significant quantities of water and most of the factories neither utilize waste minimization nor water recycling techniques. The waste treatment methods are also not adequate. Thus there is a tremendous potential on savings on one hand and a need on the other hand. It was shown that it is feasible to utilise groundwater after treatment. Manganese is not appearing to be a major problem. The problem chemical appears to be the presence of iron. Iron can be removed from groundwater using several operations. This eliminates the transport of water from outside and serves many environmental needs such as reduced traffic, removing reliance on outside sources and events etc. A pilot plant was constructed in the laboratory and four methods of iron removal were analysed. Ozonation was studied as a method of reducing this wastage. In this manner there would be a reduced demand on the freshwater resource as well as reduced discharge of effluents. Thus the situation would lead to a facility whereby the waste minimisation has taken place and a facility with positive environmental management. It has been shown that this technology offers many advantages to the industry including the recycling option. Ozonation in addition provided abilities to provide the required input quality as well in addition to being able to reduce COD, BOD and the most importantly Colour of effluents. It was seen that processes are carried out with less attention being paid to the overall efficiencies but only towards meeting production targets and/or meeting deadlines. The feasibility of recycling wastewater was shown. The practice of this would be a major improvement on the current environmental performance. iv V Table of Contents Page Acknowledgement iii Summary iv Table of Contents v List of Tables viii List of Figures ix List of Abbreviations xi Chapter I Introduction and an Overview of the textile industry in Sri Lanka 1.1 Introduction 1 1.2 The Textile & clothing industry in Sri Lanka. 2 1.3 Present Environmental Management in the Textile Industry 3 1.4 Challenges to the industry 4 1.4.1 Production, Marketing and Commercial Challenges 4 1.4.2 Environmental Challenges 7 1.5 Research Obj ectives 10 Chapter 2 Garment Washing Industry 2.1 Introduction 13 2.2 Garment Washing Industry 13 2.3 Garment Washing Process and Related Parameters 15 2.4 Quality Assurance and Control procedures 22 2.4.1 Effect of Washing on Quality of Garment 23 2.5 Water Quality requirements for Garment Washing 25 2.5.1 Impacts of adverse quality parameters. 26 2.5.1.1 The presence of heavy metal ions 26 2.5.1.2 Effect of water hardness 26 Chapter 3 An Environmental Assessment of a Textile Washing facility 3.1 Introduction 28 3.1.1 Water use and management 28 3.2 Materials and Methods 28 v 3.2.1 Survey of Garment washing Industries 28 3.2.2 Garment washing Plant Audit 28 3.2.2.1 Water Audit 28 3.2.2.2 Location of the facility 28 3.3 Methodology 29 3.3.1 Flow Measurements - Water 29 3.3.2 Flow measurements - Steam 32 3.3.3 Water & Wastewater characteristics 32 3.3.4 Rainwater 33 3.4 Results 34 3.4.1 General observations from survey and related visits 34 3.4.2 Water Audit 35 3.4.3 Organisation and Production activities 35 3.4.4 Work environment and Pollution issues of the site 37 3.4.5 Current practices of water management 40 3.4.6 Wastewter discharge and characteristics 40 3.4.7 Results (water Audit) 42 3.4.8 Input water and use characteristics 43 3.4.9 Water Quality Characteristics 43 3.4.10 Rainfall analysisand site specific requirements for rainwater 45 harvesting 3.4.11 Rainwater utilisation system 47 3.5 Discussion 52 3.5.1 Water Audit 52 3.5.2 Water Reuse and Recycling - Options and Importance 52 3.5.3 Use of rainwater 55 Chapter 4 Iron and Manganese Removal: Study of Industry Options 4.1 The importance of iron and manganese removal in textile washing 57 4.1.1 The Presence of Iron and Manganese 57 4.2 Removal of Iron and Manganese 60 4.3 Methods of Removal 61 4.3.1 Removal of Iron 61 4.3.1.1 Review of Methods 62 4.3.2 Removal of Manganese 63 4.3.2.1 Review of Methods 64 4.4 Materials and Methods 65 4.4.1 Experimental set up 65 4.5 Results and Discussion 67 4.5.1 Coagulation andFlocculation using Alum and Propriatory 67 chemicals (PC) as coagulant (Chemical Removal) 4.5.2 Aeration 73 VI -, -s < V 4.5.3 4.5.4 4.5.5 Adsorption Ion - Exchange Resins Discussion 76 80 83 Chapter 5 Ozonation : A process Solution for waste minimization 5.1 Introduction to Ozonation 85 5.1.1 Generation of Ozone 8 8 5.1.2 Process of Ozonation 90 5.1.2.1 Solubility of ozone in water 90 5.1.2.2 Mass Transfer aspect in ozonation process 90 5.1.2.3 Typical Dosage parameters and reaction times 91 5.2 Review of Ozonation applications 91 5.2.1 Drinking Water installation 92 5.2.2 Decolouration 93 5.2.3 Tase and Odour Removal 93 5.2.4 Wastewater Treatment Plant operations 93 5.2.5 Further applications 94 5.3 Materials and Methods 94 5.3.1 OzonatinUnit 94 5.3.2 Methodology 96 5.4 Results and Discussion 97 5.5 Process Economics 104 Chapter 6 Conclusions and Recommendations 6.1 Conclusions and Recommendations 107 6.2 Suggestions for Future work 113 vn V List of Tables Table No. 1.1 Textile and Garment Industry Sector 1.2 Trade and Professional Organisations 1.3 Total Imports and Exports Values for 1994 -1998 1.4 Important Issues in Relation to Textiles 1.5 Criteria for Eco-Labelling of Textiles 1.6 List of Banned withdrawn and restricted chemicals related to Textile Processing 1.7 Some International Standards specific for Textile Industry 1.8 The estimated wastewater loading from the textile sector in the Ratmalana Moratuwa area 1.9 Estimated total waste load from the Textile Manufacturing Sector 2.1 Possible Environmental Impacts at each stage. 2.2 General wastewater characteristics from Textile and Garment industries in Ratmalana t 2.3 Possible problems or faults arising as a result of inappropriate physical conditions or parameters 2.4 Deviation in process steps when utilizing impure water 3.1 Typical activities of the staff and work force 3.2 Tabulated Results of the Water Audit 3.3 Possible source water quality parameters 3.4 Wastewater Characteristics of the Garment washing Plant A 3.5 Wastewater Characteristics of another Garment washing Plant B 3.6 BOD & COD analysis for the effluent streams 3.7 Average and Extreme Rainfall Data for Colombo 3.8 Average Rainfall data at Ratmalana over last five years 3.9 Possible reduction opportunities via better Management 4.1 Sources of Iron and Manganese 4.2 Review of Methods - Iron Removal ^ 4.3 Review of Methods - Manganese Removal 4.4 Description of the selected samples for chemical addition 4.5 Cost analysis for the Trial run 4.6 Cost Analysis for the Plant 4.7 Results from Aeration Tests 4.8 Results from Adsorption Tests 4.9 Results from Ion-Exchange Tests 5.1 Comparison of Ozone with other oxidising agents 5.2 Advantages and Disadvantages of UV Vs CD Ozone 5.3 Solubility of UV produced and CD produced Ozone 5.4 Some practical data for the two parameters 5.5 Transmittance percentages for specific dye samples f 5.6 Wastewater Analysis 6.1 Additional Water related saving methods 4 viii List of Figures Figure No. 3.3 3.4 3.5 3.6 3.7 a-c 3.8 3.9 3.10 3.11 3.12 3.13 3.14 • 3.15 3.16 3.17 4.1 4.2 4.3 4.4 4.5 4.6 4.7 *. 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 4.16 Export values for the years 1990 -1998 a Conventional Process system b Modem Integrated Solution Distribution of Garment Washing Industry in Sri Lanka. Special Effect Washing in the Garment Industry Characterisation of Environmental discharges in special effect washing Care label Process parameters that govern the wash effect a Location map of the audited facility b Geographical map of the audited facility c Drain Layout of the factory Discharge to an open channel from a washing machine Open channel flow from the outlet of the factory The organisation chart of the facility a Total process block diagram diagram b Detailed Dyeing process block diagram The layout plan of the facility Detailed Piping & Instrumentation diagram for the plant Impacts Identification assessment for washing process Impacts Identification assessment for dyeing process Process block diagram of the raw water treatment plant Raw water treatment plant Process block diagram of the wastewater treatment plant General flow of water in the factory Rainfall Zones of Sri Lanka Down Pipe Self- cleaning valve Rainfall data at Ratmalana (Five Years) a Distribution of Total Iron in Sri Lanka b Distribution of Manganese ion in Sri Lanka Yellow patches in the washed garments due to iron Solubility diagrams for metals Relative oxidation requirements to achieve precipitation of iron and Manganese a Four Configurations in the trial run (Pictorial illustration) b Configuration of chemical addition (Pictorial illustration) Coagulation and Flocculation studies using Jar Test apparatus Configuration of chemical addition (Schematic) Graph of pH vs NaOH (10 % ) Graph of pH vs NaOH (10 % ) - Best Possible graph Graph of pH vs Alum concentration Graph of iron content vs PC (Time Period 5 min, rpm 150 ) Graph of iron content vs PC (Time Period 3 min, rpm 100 ) Graph of iron content vs PC (Time Period 4 min, rpm 200) Graph of iron content vs PC for different rpm values (06 values) Graph of PC vs pH (to obtain optimum PC requirement) Configuration for aeration (Schematic) 4 IX 4.17 Graph of reduction of iron vs time for different air flow rates 4.18 a & b An Industrial scale aeration unit 4.19 a Concentration ratio vs adsorption bed length b Concentration ratio vs Time 4.20 Configuration for adsorption studies (Schematic) 4.21 Ion exchange resin test column 4.22 Summary of findings 5.1 Formation of ozone 5.2 Generation of ozone 5.3 Ozone facility in the Los Angeles aqueduct filtration plant 5.4 a ozonation unit b Component of ozonation unit 5.5 The graph of iron content vs time required for ground water samples 5.6 The graph of iron content vs time required for standard iron solution 5.7 a Reactive dye (Navy Blue) b Acid dye ( Red) c Vat dye ( Brown) d Disperse dye (Orange) e Direct dye (solar Black) 5.8 a Outlet sample sfrom the factory after ozonation b Outlet samples from the wastewater treatment plant after ozonation 5.9 a Pre Desize rinse b Desize rinse c Softening d Bleaching 5.10 The total analysis of water throughout the study 6.1 Modified block diagram for the process 6.2 Modified scheme for recovery of condensate A x List of Abbreviations $ United States Currency (US Dollars) (g) Gas u-S Micro Seconds AATCC American Association of Textile Chemists and Colourists AIT American Institute of Textiles AOX Adsorbable organic halides aq aqueous AT Advance Technology BDL Below Detection limits BOD Bio Chemical Oxygen Demand C Fluid concentration at a point in a bed. Cb Break point concentration Cd Concentration at which the bed is ineffective CD Chorona Discharge CEA Central Environmental Authority CFM Chloro Fluoro Methane Co Feed concentration COD Chemical Oxygen Demand CPf Specific Heat Capacity of Fabrics Cpi Specific Heat Capacity of Water dH German Hardness E / S Enzyme / Bleach Wash EIU Economic intelligence unit EOP Electro Chemical Potential of Ozone g grams GPF Garment factory programme gpm grams per minute H B Length of bed used up to the break point H x Total Height H UNB The length of unused bed ISO International Standard Organisation J Joule K Kelvin kg kilogram kJ kilo joule Kwh kilo watt hour L Litre M Metre M.L.R. Material to Liquor ratio M F Fabric Weight MID Ministry of Industrial Development Min Minutes M L Liquid Weight Mi Liquid Weight NAFTA North American Free Trade Agreement NWS & DB National Water Supply and Drainage Board 0 3 Ozone °C Centigrade XI NAFTA North American Free Trade Agreement N W S & D B National Water Supply and Drainage Board 0 3 Ozone °C Centigrade OZAT Ozone Advance Technology P&I Piping and Instrumentation PC Proprietary Chemical pH Unit used to describe acidity or alkalinity. ppm Parts per Million Q A / Q C Quality assurance and Quality control RUS Rainwater Utilization System S Seconds SAPTA South Asian Preferential Trade Agreement SLS Sri Lanka Standards ss Suspended Solids t 4 Time equivalent to tower out put tb Breakpoint Time td Time at which the bed is ineffective ts Time for c/c0 = 0.5 t. Time equivalent to the total or stoichiometric capacity tu Time equivalent to usable capacity THM Trihalomethane TKN Total Kjeldhal Nitrogen TL Textiles and Leather TL Textile & Leather TP Total Phosphate TSS Total Suspended Solids USA United States of America uv Ultra Violet WWTP Wastewater Treatment Plant •4 xii