Colour, Emulsion and Foam in Textile and Process Wastewater: Separate Problem, Separate Test

Color, Emulsion and Foam Are Not the Same Mechanism

Although the dark, cloudy oil emulsion and dense foam seen in textile dyehouse, finishing and industrial process wastewater meet in the same pool, their chemical structures are completely different. Color is mostly caused by reactive, disperse or acid dyestuffs with high water solubility. Emulsion is the suspension of cutting/washing oils or process finishing liquids as stable micro-droplets in water with the help of surfactants. Foam occurs with wetting agents, detergents, high alkalinity and aeration turbulence. It should not be assumed that a single chemical will solve these three problems.

Separate Laboratory Test Question for Each Problem

Elif Çevre Kimya's wastewater product group includes cationic resin/polyamine-based decolorizing polymers for textile dyehouse waters, emulsion breakers for oily wastewater, and silicone or silicone-free defoamers (antifoam) for ventilation/discharge lines. In the color removal test, the pH setting, the dosage order of the coagulant (PAC/FeCl₃) and the decolorizing polymer, Pt-Co/spectrophotometric color drop and the volume of sludge formed are monitored together. While evaluating phase separation time and interface clarity in the emulsion breaking test; In the defoamer test, both the instantaneous knock-down rate and the permanent foam suppression time and its effect on biological sludge are observed.

Dosage Sequence and Chemical Compatibility

For example, administering cationic decolorizing polymer and anionic flocculant (A-PAM) from the same point or without sufficient mixing time causes the two chemicals to bind to each other and become inactivated. Field verification should be made taking into account the homogeneity of the balancing pool and shift-based dye recipe changes. Constant dosage is not guaranteed without water analysis and jar-test.

Field Control and Monitoring List

Chemical dosage and system capacity decisions should be determined by analysis and facility conditions; There is no guarantee of fixed dosage or performance.

• Taking composite samples from the balancing tank representing different dyeing shifts
• Determination of decolorizing polymer and inorganic coagulant (PAC/Iron III) dosage order with Jar-Test
• Allowing sufficient mixing/reaction time between cationic decolorizer and anionic flocculant
• When choosing a defoamer, if there is a risk of membrane (MBR/RO) or textile stains, choose a silicone-free formulation.
• Combined verification of color, COD, TSS and sludge dewatering performance in effluent