Cleaner Technology Transfer to the Polish Textile ... - Miljøstyrelsen

Topic 39.
Separation techniques for
reclamation of process water
Case illustration:
Membrane filtration and
re-use of process water
from reactive dyeing of
cotton in jet
Concept Many types of spent process waters at the point of discharge are so heavily
loaded, that a direct re-use is not possible. This applies to e.g. bleaching, dyeing
and desizing baths and the most loaded rinsing baths. Danish experience,
concerning re-circulation of process water from reactive dyeing of cotton in
jets and re-use of desizing baths have shown, that by addressing specific types
of process water, economically feasible separation techniques can be found
today, and with expectations of increased costs for water and energy in the
future, one could expect this tendency to increase. For the overall economical
feasibility for a selected reclamation method, one should take into account the
water savings possible, the value of desirable chemical agents and/or the calorific
value remaining in the process water after reclamation.
Membrane filtration, chemical precipitation, activated carbon and evaporation
have been tested. These options are further described in papers in Part 3 and 4.
Improvement potentials Large savings in water, energy and chemicals.
Relevance All companies.
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