Powder Coating Plants Wastewater Treatment With Application of The GACS Method of Zeologic S.A.

General Information
Wastewater occurring from metalworking industries is defined from the kind of procedures that are implemented to the metallic materials. Wastewater is produced from chemical processes such as metal cleaning with de-oiling or/and deoxidation, plating, coloring, phosphating. Wastewater from such procedures, occur from the discharge of all or part of the used degreasing, deoxidation, plating or passivating baths and the discharge of the cleaning and rinsing tanks. Plating baths are usually discharged partially for cleaning purposes, while complete discharge occurs in cases of deterioration of the bath's quality characteristics or in case of an accident (tank corrosion). The environmentally apt treatment and disposal of wastewater produced from powder coating plants constitutes a hard challenge for the metal industries, since the implemented techniques for such type of waste, have granted questionable results. Another significant matter of such techniques, as well is the disposal of the sludge produced as a treatment byproduct, which has to be stabilized and inactivated before the generated byproduct can be disposed safely to the environment.

The GACS Solution (Geochemical Active Clay Sediment)

The Geochemical Method GACS consists an innovative solution on an international level on the subject of treatment and disposal of wastewater produced from powder coating plants among others. The key characteristic of the Geochemical Method GACS is the usage of geopolymer materials, which have the ability to adapt on the characteristics and particularity of any type of waste, thus ensuring a successful treatment with warranty of optimal performance.
Benefits of the GACS Method, on treatment of anodizing plants wastewater against the conventional existing methods can be summarized in the following:  
Financial Benefits:
  • Competitive investment cost
  • Achievement of a significantly reduced operational cost
  • Reduced maintenance cost
  • Reduced sludge production
  • Reduced operational time
Environmental Benefits:
  • Heavy metals removal even on high concentrations (Cr,Ni etc).
  • Sulfates removal
  • Effluent complying with legislation
  • Production of inert sludge
  • Use of physical materials
  • Recovery / reuse of treated water in the production line (Zero Discharge)
Results of an indicative chemical analysis on a wide range of significant parameters on samples derived from powder coating plants prior and following the utilization of the GACS Method are presented in the table below:
Chemical Parameter Powder Coating Plants Wastewater
Initial Measurement Final Measurement Pollutant Load Removal
Ph (Units) 3,14 7,58 Neutral
COD (mg/lit) 2250 9 99,6%
NO4 (mg/lit) 19 4 78,9%
SO4 (mg/lit) 670 20 97%
PO4 (mg /lit) 0,49 0,06 87,7%
Fe (mg/lit) 4,67 0,022 99,5%
Cr (mg/lit) 11,32 0,009 99,9%
Ni (mg/lit) 1,67 0,011 99,3%
SS (mg/lit) 274 0 100%
Al (mg/lit) 800 0,58 99,9%
Zn (mg/lit) 0,74 0,008 98,9%
Pb (mg/lit) 0 0 -
F (mg/lit) 42 0.8 98%