Zero discharge of electroplating wastewater What are the treatment equipment and technology?
Wastewater in China mainly includes steel, pharmaceutical, food processing, petrochemical industry, printing and dyeing, power plant, electronic devices and other industries. The completion of zero discharge of industrial wastewater can reduce the pressure of environmental protection to a certain extent.
1、 Characteristics of zero discharge of electroplating wastewater
0 Discharge technology is to extract internal melt water from crystal chemical wastewater and use it for processing technology or other applications. The common treatment methods of waste residue include volatilization and landfill, but zero discharge of industrial wastewater has higher requirements for waste residue treatment. In general, the waste residue discharged by the zero discharge process technology is very soluble. If it is directly landfilled without solving the problem, it will cause secondary environmental pollution to the environment.
Industrial wastewater zero discharge equipment
2、 Electroplating wastewater zero discharge treatment equipment and process technology
1. Reverse osmosis method
The solution of membrane method is to concentrate the RO concentrated water step by step, increase the salt content of the concentrated water, raise the salt concentration limit value of the membrane method, or select nanofiltration membrane as required to recycle some salt in the concentrated water, so as to achieve the solution of salt separation, thereby reducing the scale of the evaporator in the subsequent process technology and reducing the process of solving the impurity salt, Reduce investment cost and operation cost, and then improve the efficiency of zero emission solution.
2. Multi effect volatilization
Multi effect volatilization is used to solve the problem of zero discharge of industrial waste water. Its characteristic is to connect multiple evaporators and use the secondary steam of the upper stage evaporator as the heat source of the lower stage evaporator, thus improving the utilization rate of heat energy. Multi effect volatilization can be used alone or in combination with other methods.
3. MVR evaporator
The technical feature of mechanical steam recompression cycle volatilization is to use the kinetic energy of the compressor to recompress the concentrated brine when the steam condenses in the evaporator and the condensed water cools, so that it can be boosted and heated up. The recovered heat energy is used to heat the concentrated brine to volatilize it. In the operation process, there is no reduction of latent heat and no need to provide external heating steam (heat source assistance is sometimes required during startup). What is consumed in the operation process is only the power consumed by the water pump, steam pump and control system that drive the sewage, steam and condensate circulating flow in the evaporator.
4. Electrodialysis
Under the action of an external DC electric field, the permeability of the ion exchange membrane (that is, the positive membrane only allows cations to pass through, and the negative membrane only allows anions to pass through) is used to make the anions and cations in the water migrate directionally, so as to achieve the separation of ions in the water from water. At present, electrodialysis has been widely used in various sewage recovery solutions.
III Electroplating equipment
A complete system solution is required to complete the zero discharge of wastewater. First, we should improve the efficiency of water use and reduce the energy consumption of the system by optimizing the process technology. The waste water will be fully reused by using reverse osmosis, electrodialysis and other process technologies. Volatilization technology is the most widely used technology for zero discharge of high salinity waste water.
Electroplating wastewater treatment equipment
Today, many industrial wastewater zero discharge equipment and technology have been created all over the country, and some key pollutant discharge companies have also completed the zero discharge of industrial wastewater, which plays a key role in China's environmental protection. Paying attention to environmental protection while economic development is the best interpretation of the sustainable development policy.
