How to Effectively Treat Electroplating Wastewater in Electroplating Wastewater Treatment Enterprises

The wastewater generated during the electroplating production process mainly comes from cleaning the plated parts, washing the ground, washing the hanging fixtures and plates, and replacing the waste tank solution. How to properly treat electroplating wastewater is crucial for electroplating wastewater treatment enterprises. There are many heavy metal ions in the waste liquid of electroplating wastewater. In order to meet environmental protection requirements, heavy metals need to be removed from electroplating wastewater during treatment. Below, Jiangsu Haipu Functional Materials, an electroplating wastewater treatment enterprise, summarizes the methods for removing heavy metals from electroplating wastewater as follows:

1. Chemical precipitation method: It is a relatively economical and effective method in the treatment of electroplating wastewater. Due to its mature technology, simple operation and management, it can simultaneously remove multiple metals from electroplating wastewater, and therefore has been widely used. Chemical agents are added to wastewater to convert heavy metal ions into insoluble heavy metal compounds, which then precipitate and separate from the wastewater, achieving the goal of removal.

2. Oxidation method: By adding oxidants, toxic substances in electroplating wastewater are oxidized into non-toxic or low toxic substances, mainly used to treat CN -, Fe2+, Mn2+low valence ions in wastewater, as well as various organic compounds that cause color, odor, and pathogenic microorganisms.

3. Chemical reduction method: The most typical application of chemical reduction method in the treatment of electroplating wastewater is the treatment of chromium containing wastewater. The method involves adding reducing agents such as FeS04, NaHS03, Na2S03, S02, or iron powder to the wastewater to reduce Cr (VI) to Cr (III), and then adding NaOH or lime milk for precipitation and separation. The advantages of this method are simple equipment, low investment, and large processing capacity, but it is necessary to prevent secondary pollution caused by sediment and sludge.

4. Air flotation method: As a technology for treating electroplating wastewater, it is a new process developed in recent years. The basic principle is to use a high-pressure water pump to pressurize water to several atmospheres and inject it into a dissolution tank, mixing air and water into dissolved air and water. The dissolved air and water enter the water tank through a dissolved air release device. Due to sudden pressure reduction, the air dissolved in the water forms a large number of microbubbles, which adhere to the condensed matter generated by the initial treatment of electroplating wastewater, making its relative density lower than that of water and floating to the surface as floating slag to be discharged, thereby purifying the wastewater.

5. Biological method: Biological treatment is a new technology for treating electroplating wastewater. Some microbial metabolites can change the valence state of heavy metal ions in wastewater. At the same time, the microbial community itself has strong biological flocculation and electrostatic adsorption effects, which can adsorb metal ions. After solid-liquid separation, heavy metals enter the sludge cake, thereby enabling wastewater to meet discharge or reuse standards.

6. Biological flocculation method: Biological flocculation method is a decontamination method that uses microorganisms or metabolites produced by microorganisms for flocculation and sedimentation. Microbial flocculants are natural high molecular weight substances produced by microorganisms themselves that have efficient flocculation effects. They have high charges or strong hydrophilicity and hydrophobicity, and can adsorb multiple colloidal particles simultaneously with particles through ionic bonds, hydrogen bonds, and van der Waals forces, creating bridging phenomena between particles and forming a network like three-dimensional structure that precipitates.

Due to its unique formation factors and complexity, electroplating wastewater needs to be customized according to the actual composition of the raw water and the specific requirements of the enterprise, often involving a combination of multiple processes. Jiangsu Haipu's independently developed special adsorption material selectively adsorbs the components or substances to be removed. When the adsorption is saturated, a specific desorption agent is used to desorb the adsorption material, allowing it to be regenerated, and this process is continuously repeated. Haipu's adsorption process can be combined with various known traditional electroplating wastewater treatment processes, especially with unique advantages in material recovery.