Effective Reuse of Electroplating Rinse Wastewater by Combining PAC with H2O2/UV Process

Area of Science:

• Environmental Chemistry
• Water Treatment Technologies
• Adsorption Science

Background:

• Electroplating wastewater poses environmental challenges due to organic compounds and heavy metals.
• Existing treatment methods like PAC adsorption or H2O2/UV oxidation alone are insufficient to meet regulatory standards.

Purpose of the Study:

• To evaluate the combined efficacy of PAC adsorption and H2O2/UV oxidation for treating electroplating rinse wastewater.
• To determine the optimal conditions for removing organic compounds and heavy metals.

Main Methods:

• Evaluating powder activated carbon (PAC) adsorption.
• Assessing hydrogen peroxide/ultraviolet (H2O2/UV) oxidation.
• Investigating the synergistic effects of a combined PAC pre-adsorption and H2O2/UV post-oxidation process.

Main Results:

• Individual PAC adsorption and H2O2/UV oxidation failed to reduce chemical oxygen demand (COD) to the required 100 mg/L.
• The combined process (5 g/L PAC pre-adsorption, 64 W UV, 100 mg/L H2O2, 90 min oxidation) reduced COD to 8.2 mg/L and dissolved organic carbon (DOC) to 3.8 mg/L.
• The integrated approach successfully removed heavy metals, meeting effluent standards and enabling water reuse within the electroplating factory.

Conclusions:

• The combined PAC adsorption and H2O2/UV oxidation is a highly efficient treatment for electroplating wastewater.
• This integrated process offers economic and environmental benefits over individual methods.
• The rapid reaction kinetics observed in the combined process highlight its superior performance.