Electroplating Industry

• Heavy metals removal like chromium, nickel, zinc, copper, cadmium, and others. Wastewater from these operations often contains high levels of toxic metals, which must be removed to meet environmental discharge standards.
• Electroplating wastewater often has extreme pH values, either highly acidic or basic, depending on the specific metal plating process. Effluent must be neutralized to meet discharge standards.
• Cyanide is used in many electroplating baths, especially for gold, silver, and zinc plating. It is highly toxic and must be fully destroyed before wastewater is discharged.
• Chromium plating uses highly toxic hexavalent chromium (Cr⁶⁺), which must be reduced to the less toxic trivalent chromium (Cr³⁺) before it can be treated or removed.
• Electroplating processes often involve oil-based substances used in degreasing or as part of the plating baths. Oil and grease in wastewater can interfere with treatment processes and need to be removed.
• Many electroplating baths use complexing agents like EDTA or ammonia to keep metals in solution. These chelating agents make metal removal more difficult as they bind tightly to metals and prevent their precipitation.
• Water conservation and reuse are increasingly important in electroplating due to both environmental concerns and cost savings.
• Due to the variability of electroplating processes and the toxicity of the wastewater, continuous monitoring and automated control systems are often implemented to ensure optimal treatment.

• Chemical Precipitation: Metal ions are converted into insoluble metal hydroxides or sulfides by adjusting the pH of the water, allowing them to be filtered out.
• Chemical Reduction: Chemical agents reduce hexavalent chromium to trivalent chromium, which can then be precipitated as chromium hydroxide.
• Coagulation and Flocculation: These methods use chemical agents to gather oil particles into larger clumps for easier removal.

• Selective Ion Exchange: Specialized resins used to capture chelated metals are often used with closed-loop systems to recirculate treated water back into the plating process to reduce the need for freshwater.
• Membrane filtration: is used in electroplating wastewater treatment to separate dissolved metals, solids, and contaminants. These membranes offer high separation efficiency and can be used as a final polishing step.
• Alkaline Chlorination: Cyanide is oxidized by chlorine or hypochlorite in a high-pH environment to form cyanate, which is further broken down into harmless nitrogen and carbon dioxide.
• Ozone Treatment: Ozone can be used as an oxidizer to break down cyanide into less harmful compounds.
• Dissolved Air Flotation (DAF): This technique floats oil and grease to the surface for removal.
• Sludge Dewatering: Technologies such as filter presses or centrifuges are used to reduce the volume of sludge, making it easier and less costly to dispose of.

Real-time monitoring: pH, metal concentration, and flow rate monitoring together with automated dosing of treatment chemicals to maintain ideal treatment conditions.