Contributor, The Textile Industry and the Environment, UNEP

20 INTRODUCTION
ness. This same awareness is also influencing the design of textile manufacturing equipment without
impairing thc product quality. Examples of such process and equipment changes include modifications
in equipment for washing, dyeing, drying and for fabric printing.
• 1.2 POLLUTION CONTROL STRATEGIES
Having reviewed and improved production processes to eliminate and reduce waste as much as possibIe,
it is then necessary to select the best effluent treatment strategy. If pollution avoidanee, recycling
and waste treatment are carefully chosen, then there should be little residue requiring treatment and
disposal. Nevertheless, all these stages must be carried out bearing in mind possible environmental
impacts, worker safety and the welfare of any neighbouring community.
Segregation and separate treatment of specific effluent streams is more efficient than attempting to
treat combined and complex effluents. Such a strategy will often provide opportunities to reuse or
recover heat or chemicals and reduce the size of the treatment plant facility. Combined chemical
and biological treatment is one of the most commonly employed methods of liquid waste treatment
in the textile industry. In such instances, flow equalisation tanks and appropriate pre-treatment units
must be constructed to remove toxic substances such as chemical additives and dyestuffs in the waste
streams and to ensure the proper operation and maintenance of any biologicaJ treatment unit. Residues
from textile operations include sludges from biological or physico-chemical units and waste materials
from the production process. Disposal alternatives include a range of options such as compaction
and landfi1ling, anaerobic digestion or incineration.
For practical implementation, the relative emphasis on these various strategies would vary. For example,
existing old textile mills with mostly batch Or semi-mechanised operating methods might find
few opportunities for new, cleaner equipment. Better housekeeping, the minimisation of chemical
usage, water reuse and low cost technologies for end-of-pipe treatments such as land application or
aerated lagoons may be the most practical approach, at least initially. For large new textile mills
using continuous methods of operation, environmentally sound processes and equipment options could
be more attractive.
• 1.3 ABOUT THIS REPORT
This report deals in detail with the complementary strategies of cleaner production and pollution control
in three sections:
• An overview of textile wet processing operations and the wastes generated.
• A description of various cleaner production options.
• A review of technological options for end-of-pipe treatment.
Additional information is provided in the appendices including a list of reading materials and journals,
cleaner production case studies and important addresses of textile research organisations, etc.
This report has been wri tten [or several audiences, each with different responsi bilities:
• For industrialists, to review the impacts of different processes and cleaner options.
• For regulators, to provide an outline of environmental considerations and an integrated pollution
control strategy.
• For operators and technicians, to provide details about the environmental implications of common
processes, cleaner manufacturing operations, and check-lists for management
decision-making.
This report will not serve as a complete and independent reference for readers wishing to develop
and implement a detailed environmental management system. Readers are urged to refer to the additional
reading material listed in the reference sections for more exhaustive and detailed guidance.