Van Gulik - Water recycling and wastewater treatment for wastewater from steel powder coating process - Case Study
Van Gulik Coatings has installed a second powder coating line at its site in de Meern in the Netherlands. The plant is capable of powder coating 18 t of steel products measuring 14.5 m in length per hour.
Approximately 2 m3/h of demineralised water is required for the pre-treatment stage. The deionised water is used for rinsing the parts that are to be coated once these have undergone degreasing, pickling and passivation. A tailored plant solution was subsequently installed for the customer in the form of the company’s Envochem® water recycling und Split-O-Mat® wastewater treatment plant technology. The Envochem® water recycling plant, consisting of a dual-layer filter, an activated carbon filter, plus two cation and two anion exchange units, is used to turn the circulating rinsing water into deionised water (< 15 µS/cm).
The used concentrate baths and regeneration flows from water recycling plant are collected separately and undergo physico-chemical treatment in the wastewater treatment plant. The water containing chromium (VI) is first decontaminated before undergoing precipitation and flocculation. The resulting flocs then undergo sedimentation in a downstream sedimentation tank. The thin sludge is dewatered in a chamber filter press.