The results of the laboratory-scale analyses have shown that decolourization of textile waste water containing reactive dyes was very efficient. This efficiency was achieved by operating a treatment train concept in which the TEXAFLOK flocculating agent was used.
The treatment train concept consists of three steps.
- In the first step, the waste water stream is treated by using the flocculating reactant. The role of this reactant is to carry out the decolourization via a chemical separating process.
- In a second step, a biological treatment degrades the organic pollution. Here, a bio filtrating device can be used to reduce the biofouling potential of the water effluent.
- Finally, an Advanced Oxidation Process (AOP) is used for heavy degradable pollution such as PCBs, phthalates or pesticides.
Lab-scale experiments have shown that a complete decolourization of mixed water streams is achieved by using the combination of these treatment technologies. As far as flocculants are concerned, these agents create insoluble compounds from the waste water. As these compounds consist of organic complexes, they can be discharged directly into the biological wastewater treatment plant without any additional separating device: sludge is therefore destroyed in a further digesting step.
The quality of the obtained treated water is equivalent to the standards required in textile water effluents. Nevertheless, a higher amount of soluble inorganic salts was found in the treated water during the tests. This higher concentration occurred due to the nature of the technology which focuses only on organic pollution and not on desalinating wastewater so that these salts could not be removed from the effluent.
Furthermore, in order to validate the reusability of the treated water in a wide range of finishing technologies, a number of laboratory scale experiments were conducted in several fields such as demineralization, bleaching of flax combed sliver, dyeing of textile with reactive and disperse dyes. As a result, the quality of textiles, treated with the reused water, was appraised to be practically equivalent to those treated with fresh water.
These laboratory scale trials are still to be confirmed in field. Industrial verification of these promising observations is needed to validate the technology.