World Water Day 2021: Treatment of Dyehouse Effluents with PERIFLOC

World Water Day is an annual UN observance day to highlight the importance of water. Due to the coloring of the effluents and the large volume of wastewater generated, the treatment of colored drainage from textile finishing, dyeing and printing is fundamentally important. On the occasion of this year's World Water Day 2021 on March 22, we will present solutions for decolorizing textile effluents with PERIFLOC flocculants.

Purified, decolorized wastewater which can be discharged to public treatment plant is flowing from a sewage pipe.

Decolorized, treated wastewater from dyeing and finishing mills can be discharged into the public sewage system for further purification.


Decolorizing colored dyehouse wastewater with flocculants

Dyehouse wastewater, but also effluents from printing plants or laundries, are frequently tinted with residual dyes, water-soluble dyestuffs or colored pigments. Worldwide, the textile industry produces hundreds of millions of cubic meters of dyed wastewater, which, if not decolorized or treated, could reach surface water and pollute it.

Many finishing plants run on-site wastewater treatment facilities. For decolorization water-soluble dyestuff molecules in the wastewater can be precipitated with special flocculants. Usually, inorganic or synthetic organic flocculants and coagulants are used. First of all, the dyestuff molecules are precipitated with primary flocculants. Subsequently, the size and weight of the agglomerates should be increased with the help of so-called secondary flocculants in order to produce larger flocs. The mechanical mixing of the effluents with the flocculants has to be followed by a motionless sedimentation phase. Turbulence and shear forces could otherwise cause the relatively unstable agglomerates of flocculants and dyes to be disrupted again. Finally, the solid and liquid phases are separated by flotation or sedimentation and the sludge is disposed of accordingly. The decolorized wastewater can then be discharged into the sewer system for further wastewater treatment.

UN World Water Day on March 22, 2021

World Water Day has been held annually on March 22 since 1993 and is convened by UN-Water. UN-Water is part of the United Nations. On UN World Water Day, the focus is on current water issues. Main topics are the reduction of water pollution as well as the reduction of freshwater consumption. World Water Day 2021 is about what water means to people, its true value and how we can better protect this vital resource.


PERIFLOC Flocculants for Sewage Treatment

We have various PERIFLOC flocculants for sewage treatment in our product range: PERIFLOC primary flocculants are added to form agglomerates for decolorizing the wastewater from wet finishing. PERIFLOC secondary flocculants can then be added to induce the formation of larger, more voluminous flocs.

PERIFLOC Primary Flocculants:

  • PERIFLOC RS conc.

    PERIFLOC RS conc. is a cationic condensation product used for flocculation of anionic dyes, particularly of reactive, direct and acid dyes, in the wastewater. It is applicable in wastewater treatment facilities and purification plants.


    PERIFLOC SFA is an anionic condensation product applied for flocculating cationic dyes, especially basic dyes, from effluents and in sewage treatment plants.


PERIFLOC Secondary Flocculants:


    PERIFLOC AC 100 is a non-ionic secondary flocculant in powder form. PERIFLOC AC 100 is used together with cationic primary flocculants such as PERIFLOC RS conc., PERIFLOC AC 100 supports floc formation and improves flocculation properties such as floc size, density, filterability and dewatering properties.



Application of PERIFLOC Flocculants

The use of the PERIFLOC flocculants depends on the type and the amount of residual dyes in the wastewater. The optimum application quantity of PERIFLOC flocculants needs to be determined in tests with the respective wastewater. Preliminary tests in the laboratory are necessary, as the flocculation process depends on various further parameters, such as temperature, pH value, etc. In case of underdosing, the wastewater will not be completely decolorized. If overdosed, the wastewater would be polluted by excess flocculants. In addition, overdosing of the flocculant can impede the flocculation and, in the case of severe overdosing, can prevent it completely.

Of course, our experts will be happy to advise you on the right products for your operation and support you in determining the correct application quantities. Contact our specialists directly by e-mail.

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