Case study on the comprehensive advanced treatment of PCB electroplating wastewater

With the rapid development of the electronics industry, the manufacturing quantity of printed circuit boards (PCB) has grown swiftly. The production process generates a large amount of electroplating wastewater, with high contents of heavy metals and refractory organic compounds, making it difficult to be treated. Taking the electroplating wastewater treatment project in an industrial park as an example, according to the principle of classified collection and quality-based treatment, eight different types of wastewater (including cyanide nickel wastewater, etc.) were collected separately. After quality adjustment, the wastewater entered the chemical pretreatment unit. After the effluent met the Electroplating Pollutant Emission Standards (GB 21900-2008), it proceeded to the comprehensive wastewater treatment system. The treatment process included “coagulation sedimentation tank+hydrolysis acidification tank+denitrification A/O+secondary sedimentation tank+high-efficiency sedimentation tank+advanced catalytic oxidation tank+aeration biological filter (BAF)+sodium hypochlorite disinfection”. The design essentials of the PCB electroplating wastewater treatment process were summarized, and the selection of key parameters in the design process and cost-effectiveness analysis were discussed. After chemical pretreatment, biochemical treatment, and advanced treatment, the effluent of PCB production wastewater was superior to the Class A standard of the Urban Wastewater Treatment Plant Pollutant Emission Standards (GB 18918-2002), which provided a reference for the design and operation of similar wastewater treatment.