As you have said in your question, there are different effective methods for the treatment of organic matter and colour in textile effluents. However, any of them is free. Only after a complete study of the textile processes and the application of pilot-plant studies a comparative estimation can be achieved. In these studies the reuse of the treated effluents in the textile factory processes should also be considered for environmental and economic reasons.

 Prof. Julio Sanz- So do you agree according to your experience that the quantity of the dye found in the textile wastewater can be in the following order: Package Dyeing ˂ Jet Dyeing ˂ Garment Dyeing ˂ Beam Dyeing ˂ Pad Dyeing ˂ Jig Dyeing ˂ Skein Dyeing ˂ Stock and Top Dyeing ˂ Yarn Dyeing?

Dear professor Aljerf, you can find some classifications according to the textile dyeing processes, but that is generally speaking.

Chemicals in dyeing procedures are calculated following material-water ratio for any particular machine, and dyestuffs are proportional to textile material weight. Apart from that, the different natural and synthetic fibres andthe dyeing processes used reach unequal fixation rates. Therefore, dyeing in the same machinery polyamide material or acrylic material (using the adequate dyestuffs) or cotton (using reactive or direct dyestuffs), the colour remaining in the last effluent (cotton) will be always more intense. The fixation into the fibres is very variable and various data must be taken into consideration.

Examples of research studies like this one: http://infohouse.p2ric.org/ref/15/14114.pdf

can be found, but cannot be considered adequate for any textile dyehouse.

Dyehouses in Spain apply several treatments to their effluents (physical, chemical, biological and tertiary) according to their particular effluents and government laws.

Best regards

Dear Professor Loai Aljerf, it is true that some of the degradation products of dyes could be more toxic to aquatic organisms and fishes than the parent dyes and also the residual oxidants left in the treated water also can cause destruction of some microorganisms. Of the oxidants, ozone is quite good as its half life is very short but ozone itself is toxic and also the cost of ozone generation is high. Therefore recovery of dyes from effluent other than reactive dyes could be a good option as reactive dyes in the effluent are already hydrolyzed. Ultrafiltration and reverse osmosis filtration could be used to recover acid and basic dyes from effluent and can be reused. Separation of dyes from effluent by using absorbents also a cheap process and activated sludge could be one of the cheapest absorbents.

But when I compared the existence of specific dye chemical substance in a textile dyestuff I found the concentration of this organic dye in the range: 0.02-0.09 mM (10-50 mg/L) according to the following order of dyeing practices: 

Package Dyeing ˂ Jet Dyeing ˂ Garment Dyeing ˂ Beam Dyeing ˂ Pad Dyeing ˂ Jig Dyeing ˂ Skein Dyeing ˂ Stock and Top Dyeing ˂ Yarn Dyeing.

The technical data registered at the site was: water consuming to manufacture 1 kg of fabrics, industrial flow rate in the working day, effluent velocity, wastewater residence time, dry weight of SW per 1 kg fabrics, and rate of energy utilization are as follows: 55-65 L, 4000-5000 m3/day, 3.5 m/s, 15 s, 520 g, 2-25 MJ/kg product, respectively. Concerning SW includes waste fiber, residues from finishing chemicals, hydrocarbons, dyes and chemicals from solvent recovery systems, sludge from effluent plant, dye containers, chemical containers, pallets, fly ash and general paper trash. Besides, the dye as I mentioned before was estimated by 10-50 mg/L IWW being visible to the naked eye.

Dear Prof. Loai Aljerf

Water soluble dyes in the effluent can be removed efficiently,with very minimum cost by using Polyelectrolytes.The problem comes in the case of Pigments which needs floccullents.By products here is harmful for aquatic life.

Dear professor Aljerf,

A research article you should know is the following: 

BOOK SECTION. Pereira, Dyes-Environmental Impact and Remediation 2012

http://repositorium.sdum.uminho.pt/bitstream/1822/25109/1/Ch%25204%2520-%2520Dyes.pdf