Danish experience. Best Available Techniques – BAT - in the clothing and textile industry
3. Cleaner technology – chemical savings and substitutions
The chapter is divided into two parts:
| 3.1 | Implementation of a score system for sorting of chemicals and dyestuffs on
Basis of Environment Data and Information on Consumption. |
| 3.2 | Chemical savings. |
Part 3.1. deals with a score system, which is an administrative method of sorting
chemicals on basis of information, especially from the specification sheets of the
chemical suppliers. The sorting permits a priority selection of chemicals which, because
of actual consumption and information on environmental behaviour, should be subject to
closer examination.
Part 3.2. deals with the subject "Chemical savings" i.e. possibilities to eliminate or reduce the use of chemicals.
3.1 Implementation of a score system for sorting of chemicals and dyestuffs on Basis of Environment Data and Information on Consumption
3.1.1 Description
The score system is an administrative tool to indirectly control of the discharge of chemicals and dyes from the textile industry. It is a system of sorting of chemicals based on environmental data, consumption and discharge data. Sorting of various chemicals makes it possible to perform a prioritised selection of chemicals which should be examined closer due to consumption and environmental impacts. Upon the assessment of the score of a particular chemical, a company can then make management decisions on reduction of the consumption or substitution of the chemical with a compound that exerts less impact on the environment.
The score system is based on the parameters usually considered to be the most interesting in connection with characterisation of substances injurious to the industrial sewage environment:
- Discharged amount of substance
- Biodegradability
- Bio-accumulation
- Toxicity
If no information is available, the parameter is given the highest score and marked with an "U" for unknown.
For more details refer to "Score System for Sorting of chemicals" in Annex A.
3.1.2 Main achieved environmental benefits
The score system is an in-house operational management system, which gives a very good survey of all the chemicals and dyestuffs used in the production. In addition, it gives an easy survey of the chemicals and dyestuffs without any information available about the environmental impact. When the score system is implemented, it will impose the dyeing mills to be aware of what kind of products they use and why. Furthermore, sorting of various chemicals makes it possible to perform a prioritised selection of chemicals.
3.1.3 Cross-media (whole environment) effects
Reduced amount of persistent/toxic/bio-accumulable components in wastewater.
3.1.4 Applicability
This option can be implemented in all types of textile companies; new or existing, large or small.
3.1.5 Economy
To implement the score system, the authorities and the companies have to allocate the necessary man-hours to set-up the system. Once the authorities have made the system operational, a company has to allocate approximately 100-150 man-hours for the necessary preparation to implement the system. Once the company has implemented the system, they only have to allocate approximately 25-50 man-hours every year for maintenance of the system.
3.1.6 Driving force for implementation
The first Score System for sorting of chemicals on the basis of environmental data and on information about consumption was developed by Ringkjoebing County in 1989. The system was set up because of a large number and a high amount of different chemicals and dyestuffs being used in three dyeing mills. The complex mixture of chemicals made it impossible to set-up a specific program for analysing the nature and amount of harmful substances in the wastewater. And if it were possible, such an analysis program would have been too expensive for the companies to implement.
The driving force for implementation of the system was demands from the authorities. The implementation of the score system is now a part of the environmental permits for the clothing and textile industry in Ringkjoebing County. Furthermore, several dyeing mills outside Ringkjoebing County have implemented the system voluntarily because of the advantages of the system.
3.1.7 References to literature and example plants
Literature:
Score System for Sorting of Chemicals. On basis of Environment Data and Information on Consumption. Compendium, 2nd revised edition. January 1994.
Example plants:
| Kemotextil A/S | |
| Mørupvej 28 | |
| 7400 Herning | |
| Denmark |
|
| Att: | Mr Henrik Ellerbæk |
| Phone: | + 45 97 12 19 00 |
| Fax: | + 45 97 12 16 62 |
| e-mail: | he@kemotextil.dk |
| |
|
| Gabriel A/S | |
| Hjulmagervej 55 | |
| 9100 Aalborg | |
| Denmark |
|
| Att: | Mr Kurt Nedergaard |
| Phone: | + 45 96 30 31 00 |
| Fax: | + 45 98 13 25 44 |
| e-mail: | tina.mai@gabriel.dk |
| And many more in Denmark. | |
3.2 Chemical savings
In connection with textile processing (especially wet treatment), many different types of chemicals are used. The following CT-options should be considered:
- Collection and re-use of after-treatment chemicals in finishing.
- Omit the use of detergents for rinsing after dyeing.
- Use only neutralisation after dyeing when using VS reactive dyestuffs.
- Omit the use of complexing agents.
Option B, C and D have been described in details in chapter 2 with the title "2. Cleaner Technology in reactive dyeing of cotton". It should be emphasised that option D is relevant in general in connection with textile wet processing.
3.2.1 Description
A) Collection and re-use of after-treatment chemicals in finishing.
Chemically loaded spent baths in varying amounts and compositions are produced within the textile industry. These baths are often discharged along with the wastewater leading to an impact on the environment and waste of resources. Certain baths, especially in connection with finishing, could be re-used after a simple filtration. In a printing house, for instance, it is possible to collect and reuse the softening agents. The equipment is very simple; mechanical filter, pump and hose. The filtered softening agent is returned to the dosing tank.
3.2.2 Main achieved environmental benefits
The main environmental benefit is reduction in the pollution load of wastewater. In a Danish pigment print-house, the implementation of this option for softening agents has reduced the consumption (and discharge) by approximately 20,000 kg/year.
3.2.3 Cross-media (whole environment) effects
 | Reduction in consumption and emission of chemicals. |
| Ability to re-use chemicals. |
3.2.4 Applicability
In principal, this option can be implemented in all types of textile companies involved in finishing; new or existing, large or small.
3.2.5 Economy
In the Danish case mentioned above, the total capital costs (mechanical filter, pump and hose) are estimated at approximately 2,000 DKK (» 250 EUR). Change in operating costs (before and after implementation) is negligible. The economic value of softening agents is in the range of 0.5-1.25 DKK per kg (savings approximately 17,500 DKK). Hence the total annual savings are approximately 15,500 DKK (» 2,000 EUR). Payback time is estimated at about two months.
3.2.6 Driving force for implementation
Substantial costs for chemicals in general.
3.2.7 References to literature and example plants
Literature:
DANCEE, 1999. Cleaner Technology Transfer to the Polish Textile Industry. Idea catalogue and selected options, 1999. Danish Ministry of Environment and Energy. Danish Environmental Protection Agency. DANCEE – Danish Co-operation for Environment in Eastern Europe.
Example plants:
| Danish Colour Design Textile Print A/S | |
| Mylius Erichsensvej 52 | |
| 7330 Brande | |
| Denmark |
|
| Att: | Mr Benny Hansen |
| Phone: | + 45 97 18 19 22 |
| Fax: | + 45 97 18 19 11 |
| E-mail: | dcd@teliamail.dk |