The electroplating wastewater treatment equipment can remove heavy metal ions such as zinc, iron, copper, nickel chromium, etc. from the electroplating zinc wastewater generated by the galvanizing plant, and can also remove colors, oil stains, suspended solids, etc. from the electroplating zinc wastewater. From the production process of electroplating plants, electroplating wastewater can be divided into four categories: pre-treatment wastewater, coating rinsing wastewater, post-treatment wastewater, as well as waste plating solution and waste stripping solution. Electroplating waste liquid: The commonly used plating solution in electroplating operations such as electroplating, passivation, and stripping has accumulated many other metal ions after long-term use, or due to the damage of certain additives, or the imbalance of the proportion of certain effective ingredients, which affects the quality of the coating or passivation layer. Therefore, many factories discard a portion of the tank solution and supplement it with new solution in order to control the impurities in these tank solutions within the permitted range of the process. Some factories also discard all of these failed tank solutions. These discarded solutions of various concentrations generally have high concentrations of heavy metal ions and accumulate a lot of impurities. Not only do the types of pollutants vary, but the concentrations of the main pollutants, other metal impurity ions, and solution media also often have significant differences. These differences determine the diversity of treatment technologies and the specificity of processes for these wastewater.

Wastewater classification

One Chromium containing wastewater: mainly treated with reduction for hexavalent chromium.

II Cyanide containing wastewater: mainly treated by breaking cyanide.

III Other wastewater: including copper, nickel, zinc, etc.

scope of application

Electroplating factories (electroplating nickel, electroplating zinc, electroplating copper, etc.), printing factories (small water printing electroplating wastewater), metal product companies (various electroplating wastewater containing heavy metals).

Processing technology

Workshop electroplating wastewater (plating aid wastewater) ->Collection tank ->PH adjustment tank ->Coagulation reaction tank ->Sedimentation tank ->Intermediate water tank ->Quartz sand filtration ->Clear water tank ->Standard effluent

Currently, physical and chemical methods are generally used for processing. There are many effective methods for handling it, but not many can achieve overall compliance. But there are also those who do well, such as the DTCR heavy metal ion capturing agent from Shaanxi Futian Bao Company. It forms a large molecule chelate with heavy metal ions in wastewater through DTCR, and then undergoes flocculation to effectively remove heavy metal ions from electroplating wastewater, meeting national standards.

The wastewater treatment equipment of the galvanizing plant consists of a regulating tank, a dosing box, a reduction tank, a neutralization reaction tank, a pH regulating tank, a flocculation tank, a inclined tube sedimentation tank, a box filter press, a clean water tank, an air flotation reaction, an activated carbon filter, etc.

wastewater discharge

Most electroplating factories engage in comprehensive multi plating operations, involving multiple plating types such as chromium, nickel, zinc, copper, etc. Based on the type of plated parts, they can be divided into metal plated parts and plastic plated parts. Although cyanide containing electroplating processes are outdated and mostly eliminated, many electroplating factories still use them.

The production process of a general electroplating factory is as follows: the electroplating production process mainly includes mechanical polishing (grinding or rolling) → degreasing → acid etching → electroplating → drying → qualified products are stored in the warehouse

Unqualified products are stripped of plating

The electroplating industry implements clean production

Clean production refers to continuously adopting measures such as improving design, using clean energy and raw materials, adopting advanced technology and equipment, improving management, and comprehensive utilization to reduce pollution from the source, improve resource utilization efficiency, reduce or avoid the generation and emission of pollutants in the production, service, and product use processes, in order to reduce or eliminate harm to human health and the environment.

Pre treatment of plated parts: mechanical polishing (polishing or rolling)

The main method is to use specially designed machinery to remove burrs, scratches, weld beads, sand holes, etc. on the plated parts using polishing wheels or belts (or abrasive removal using rollers and abrasives to remove rust on certain plated parts), in order to improve the flatness and quality of the plated parts. There is no wastewater discharge in this process.

Degreasing

The plated parts of metal products inevitably adhere to a layer of oil stains due to various processing and treatment. To ensure a strong bond between the coating and the substrate, the oil stains on the surface of the plated parts must be removed. There are many oil removal processes, mainly using organic solvents for oil removal. The processes are as follows:

Polished parts → Rinse with clean water → Organic solvent degreasing tank → Clean water tank → Rinse with clean water

The wastewater in this process mainly comes from the rinsing process with clean water, and the pH value of the water is between 8.5-10.