Plating Industry Wastewater Treatment
Industrial Wastewater Treatment Success Stories
Simplified Treatment Back Into Compliance
In the manufacturing of certain mirrors, a strong copper solution at low pH is used to apply a thin coating to the glass surface. After adhesion, the excess is washed off and collected as wastewater. The wastewater at this facility is treated using 4 chemicals: caustic to raise the pH to 8.5, DTC (dithiocarbamate) as a metal precipitant, an organic based coagulant, and an anionic flocculant. The facility was in and out of compliance with residual copper in their effluent due to the fine pin floc carryover.
By pH adjusting to 8.0 and the use of Floccin-A, the treatment is simplified, easier to control with limited operator attention, makes a drier sludge, floc that settles faster, and maintains compliance with the effluent copper levels. In addition, the usage of the DTC relieves the facility from the liability of the use of this product, a regulated biocide with adverse effects to the downstream POTW if discharged.
Lead Metal Plating Operation
Eliminated Re-treatment with Lower Discharge Levels
A Midwest company is plating lead and etching the material with an HCl batch. The resultant wastewater had a lead concentration of 2,000-4,000 ppm. Traditional chemistry (pH adjustment to 9.8, coagulation/flocculation) could only decrease the concentration to 5.0 ppm. The facility was having to retreat the wastewater and only then could reach a lead level of 3.0 ppm.
With the use of the IE-061 (metal precipitant) and Floccin-A, they were able to obtain an effluent lead level of 0.4 ppm, below their discharge limit of 0.8 ppm in a single treatment. This was achieved with the use of an ORP controller with proportional 4-20 mA output to the chemical pump feeding the IE-061. The Floccin-A is then added to coagulate/flocculate the metals into a sludge for dewatering in their Plate & Frame press.