Direct re-use of waste water

Re-use of waste water requires the installation of drains above the dyehouse floor for ease of access and possible segregation of effluent streams. - Provision should be planned for storage and distribution of treated efQuents suitable for reuse to selected machines. Each machine or machine section should have two entry ports so that alternative process water sources can be utilised. Re-use of waste water can be done in very different ways and depends on the sources and sinks as described previously. A potential of up to 70% reduction of waste water has been identified at a dyehouse.  

It has also been reported that spent dyebath water can be re-used by decolouri-sation with ozone. Such decolourised liquors could be successfully used in the dyeing of polyester. The dyeing of cotton fabric with reactive dyes can be carried out using a modified dyeing method. Ozonated dyebaths can be re-used for the bleaching of cotton fabric and even for fabric whitening and rinsing, provided the effluent is extensively decolourised. 

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