3. Notes on the analysis and evaluation of environmental impacts

Contents - Previous - Next Volume

3.1 Air pollution control

Over a long period the fine dust in cotton mills can trigger damage to the respiratory tract and the lungs, resulting in a disease called byssinosis. For this reason industrial countries prescribe maximum dust concentrations, but these vary from country to country and are also measured and assessed by different methods (maximum occupational limits - MAK values) in the FRG and the OSHA rules in the USA), e.g.:

- Germany, Switzerland : 1.5 mg per m³ total dust content
- USA, Australia : 0.5 mg per m³ fine dust

Netherlands : 15 µm in the preliminary works 0.2 mg per m³ fine dust in the spinning mill

- Great Britain : 0.5 mg per m³ total dust
- Sweden : without fibres.

In Germany, the TA-Luft [Technical Instructions on Air Quality Control] (2) applies to the operation of furnace plants, and more recently also to drying plants (tenters), i.e. there is an approval obligation. Similar regulations apply in some other European countries too.

For other mostly gaseous substances which constitute a health hazard, the occupational limits of the Deutsche Forschungsgemeinschaft (German Research Foundation) are applicable.

Table 2 - Main sources of waste air emissions in textile finishing operations

3.2 Noise protection

Noise is a serious problem in spinning and weaving mills. As mentioned earlier in section 2.2, sound levels of 70 to 110 dB(A) are commonplace.

In Germany, guideline no. 2572 of the German Association of Engineers VDI (Geräusche von Textilmaschinen), must generally be complied with (25).

Today, to prevent any adverse effects on health, individual hearing protection (ear plugs, ear muffs) must be provided from 85 dB(A) and are essential from 90 dB(A), according to the ordinance on workplaces Arbeitsstätten-Richtlinien and VDI guideline 2058, sheet 2.

Because of building insulation, which is standard and indeed compulsory (VDI 2571) today, external sound propagation is relatively low. Where other facilities are close by, DIN standard 18005 applies in Germany (23). The minimum distance of textile manufacturing plants from residential accommodation is established in North Rhine Westphalia in the so-called Abstandserlaß [distance decree] of the Minister for Employment, Health and Social Affairs (Minister für Arbeit, Gesundheit und Soziales - 26).

3.3 Water pollution control

· Wastewater pollution parameters

The substances found in wastewater are classified by the proportions which can be precipitated and those which can be oxidised biologically or chemically. Chloro-organic compounds and toxic substances are also taken into account to a certain degree, e.g. some heavy metals used in textile finishing.

Anhang 38 [Appendix 38] of the Allgemeinen Rahmen-Abwasser-VwV [General Administrative Framework Regulation on Wastewater] for textile production and finishing (5) applies to the textile processing industry in the German Federal Republic. It contains a range of wastewater requirements throughout the treatment plant which may not be achieved by dilution or mixing.

The main contamination parameters are described briefly below.

For indirect discharges, state-of-the-art requirements apply, and for direct discharges the requirements of the generally accepted codes of practice also apply.

The draft of the said Anhang 38 of the Allgemeinen Rahmen-Abwasser-VwV specifies, for example, (6) the following requirements for wastewater discharged from textile mills (with the exception of water from raw wool washing, cooling systems, stencil plate production and chemical cleaning (dry cleaning) which are covered by special provisions).

- requirements according to the generally accepted codes of practice (additional for direct discharges)

COD 160 mg/l ammonium nitrogen 10 mg/l
BOD₅ 25 mg/l aluminium 3 mg/l
iron 3 mg/l total phosphorus 2 mg/l

- requirements per the state-of-the-art (for direct and indirect discharges)

Cu 0.5 mg/l AOX 0.5 mg/l
Cr VI 0.5 mg/l HHHC 0.1 mg/1
Ni 0.5 mg/l free chlorine 0.3 mg/l
Pb 0.5 mg/l HC 15.0 mg/l
Zn 2.0 mg/l sulphide 1.0 mg/l
Sn 2.0 mg/l sulphite 1.0 mg/1
TF dilution factor of 2
Colour: yellow 436 nm 7m - 1
red 525 nm 5m - 1
blue 620 nm 3m - 1

- General requirements

temperature max. 35°C at the point of discharge
pH 6 - 9 at the point of discharge
settleable solids 1.0 ml/l after 0.5 h settling time
odour no unpleasant odours
colour no visible discoloration of the wastewater

Abbreviations:

- COD chemical oxygen demand
- BOD₅ biochemical oxygen demand in 5 days
- TF toxicity to fish
- AOX adsorbable organically bound halogen
- HHHC highly volatile halogenated hydrocarbons
- HC hydrocarbons
- EDTA ethylenediaminetetraacetic acid
- NTA nitrilotriacetic acid
- PVP polyvinylpyrrolidon

The following substances, mixtures etc. may never be discharged as wastewater or with wastewater:

- chromium VI compounds from the oxidation of sulphide dyestuffs
- chloro-organic carriers
- halogen-organic solvents
- arsenic and mercury and their compounds from use as preservatives
- pollutant concentrates, such as residual sizes, residual high-grade finishing agents, print pastes, dye preparations, residues of chemicals used, textile auxiliaries and dyes from drums
- surfactants which do not meet the requirements of the WRMG [law relating to the environmental compatibility of washing and cleaning agents] (22).

All these substances must be collected, recycled where technically feasible or disposed of correctly.

For partial wastewater flows, particularly from the following departments: desizing, bleaching, printing, dyeing, finishing, coating and backing, together with central barrel and drum cleaning, threshold values apply above which treatment is required. If various processes are carried out consecutively in a single mechanical unit, the wastewater from each must be dealt with as a partial flow.

Threshold values for partial wastewater flows beyond which treatment is required:

AOX 3.0 mg/l Cr 2.0 mg/l
HHHC 1.0 mg/l Cr VI 0.5 mg/l
HC 50.0 mg/l Zn 10.0 mg/l
Cu 2.0 mg/l Sn 10.0 mg/l
Ni 2.0 mg/l

The AOX threshold value for bleaching with chlorine to obtain a particular shade of white and the non-felting finishing of wool is 8 mg/l (up to 31.12.1996 max.).

All analyses and measuring procedures required to determine the said pollutants have now been standardised in Germany to DIN.

Table 3 - Measuring procedures for wastewater parameters in the wastewater treatment plant

¹ DIN = German Standard
² DEV = Deutsches Einheitsverfahren (German standardisation procedure)

4. Interaction with other sectors

While, on the raw materials side, the textile industry has close connections with plant production (natural fibres), the fibre industry (synthetic fibres) and the chemical industry (chemical, dyes, auxiliaries), its activity on the sales side is characterised by its interaction with the clothing industry downline.

Further references to relevant project areas are given in the text.

5. Summary assessment of environmental relevance

In investment projects in the textile industry sector a range of environmentally relevant criteria must be taken into account at the location planning stage. In raw material producer countries in particular special consideration must be given to the effects of material production. The early and full involvement of the population groups affected, particularly women in some cases, can help resolve any problems which may arise.

Special attention must also be paid to the environmental impacts of raw wool washing and textile finishing plants. While in the former the problem is posed by the considerable degree of wastewater contamination, in textile finishing mill projects due account must be taken of the high water and energy consumption, the wide use of chemicals, the process-specific pollution of wastewater and exhaust air and the disposal of waste. In this regard, special industrial environmental protection officers must be appointed.

The current state-of-the-art in the processes, process installations and supply and disposal plants, together with relevant laws and their enforcement, combine to ensure that thoroughly environmentally sound textile production is possible at all stages of manufacture.

With regard to the socio-economic environmental impacts of textile projects mention should be made of the much more stringent requirements relating to personnel qualification. The capital-intensive nature of modern, extensively automated spinning, weaving and knitting mills is leading to the maximisation of machine operating times, thus multi-shift operation, usually 7 days per week, is the norm.

The whole area of socio-economic and socio-cultural aspects of this type of operation and its legislative framework must be looked at carefully.

6. References

1. Düring, G.: VDI-Berichte, Nr.310, 1978.

2. Technische Anleitung zur Reinhaltung der Luft - TA-Luft of 27.02.86; Gemeinsames Ministerialblatt GMBI 1986.

3. Year books for 1988 and 1990 of the Gesamtverband der deutschen Textilveredelungsindustrie, TVI-Verband EV.

4. 83. Allgemeine Verwaltungsvorschrift über Mindestanforderungen an das Einleiten von Abwasser in Gewässer (Textilherstellung) - 38. AbwasserVwV - of 5 September 1984, GMBI (joint ministerial circular) 1984.

5. Anhang 38 to the Allgemeinen Rahmenabwasserverwaltungsvorschrift für die Textilherstellung - Draft of 20 December 1990.

6. Dr. Heimann, S.: Textilhilfsmittel und Umweltschutz; Melliand Textilberichte, 7/1991.

7. Natke, H.G., Thiede, R., Elmer, K.: Curt-Risch-Institut für Dynamik, Schall- und Meßtechnik, Universität Hannover: Untersuchungen der von Webereien ausgehenden Schwingungsemissionen und Hinweise zur Websaal-Bauplanung. Verband der Nord-Westdeutschen Textilindustrie Münster; Zeitschriftenreihe, Heft 66, 1985.

8. Trauter. R.: Rückgewinnung und Wiedereinsatz von Webschichten mittels dynamisch geformter Membranen; Chemiefasern/Textilindustrie 37/89, 1987.

9. DIN 38409-H14-H14: Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlamm-Untersuchung: Bestimmung der adsorbierbaren organisch gebundenen Halogene (AOX).

10. 2. Verordnung zur Durchführung des Bundes-Immissionsschutzgesetzes (Verordnung zur Emissionsbegrenzung von leichtflüchtigen Halogenkohlenwasserstoffen - 2 BImSchV of 21 April 1986); BGBI (Federal Law Gazette) 1986, Part 1.

11. Kolb, M., Funke, B.: Die Entfärbung von textilem Abwasser mit Fe(II) + Ca(OH)₂; Vom Wasser, Bd. 65, 1985.

12. Wysocki, G.; Höke, B.: Chemie-Technik, 1974.

13. Oehme, Ch.: Trägerbiologien in der Abwassertechnik; Chem.-Ing.-Tech. 56, 1984.

14. Croissant, B.: Efferenn K.; Frahne, D.: Reaktivfarbstoffe im Abwasser - sind sie durch ein bakterielles Symbiosesystem abbaubar? Melliand Textilberichte, 1983.

15. Erlaß über Richtlinien für die Anforderungen an Abwasser bei Einleiten in öffentliche Abwasseranlagen of 28 June 1978.

16. Wiesner, J.; Jochen, E.: Energieverbrauch und Möglichkeiten rationeller Energienutzung in der Verarbeitenden Industrie in Baden-Württemberg: Textilindustrie, Informationen zur Energiepolitik, Heft 11c, Wirtschaftsministerium von Bad.-Württ., Stuttgart, 1978.

17. Reetz, H.: Europäische Abwasserregelungen im Vergleich; Melliand Textilberichte, 11/1991.

18. Christ, M.: Wärmerückgewinnung und Abluftreinigung bei der Textilveredlung; Textilpraxis International, 46/1991.

19. Änderung der 4. BImSchV Nr. 5.3 - Genehmigungspflicht für Anlagen der Textilveredlung und von Feuerungsanlagen.

20. "Wastewater purification" working party J. Janitza, S. Koscielski, M. Schnabel of the ITV (Institut für Textil- und Verfahrenstechnik Denkendorf) Behandlung von Textilabwässern im Betrieb; Textilpraxis International, November 1991.

21. Gesetz zur Ordnung des Wasserhaushaltes (Wasserhaushaltsgesetz - WHG) of 23.09.1986.

22. Gesetz über die Umweltverträglichkeit von Wasch- und Reinigungsmitteln of March 05, 1987.

23. DIN 18 005; Schallschutz im Städtebau, Planungsrichtlinien.

24. VDI 2058; Beurteilung von Arbeitslärm am Arbeitsplatz hinsichtlich Gehörschäden.

25. VDI 2571 + 2572; Schallabstrahlung von Industriebauten.

26. Abstandserlaß (RdErl. d. Ministers für Arbeit, Gesundheit und Soziales NW of March 09, 1982).

27. Verordnung zur Eigenüberwachung von Abwasser, Bayern (AbwEV) of December 09, 1990.

28. ITMF; International Textile Manufacturers Federation - International Textile Shipment Statistics, Vol. 14/1991.

29. World Bank; Environment Guidelines; Washington 1988, p.451 ff.

Contents - Previous - Next Volume