one, Overview of electroplating wastewater
Electroplating wastewater refers to all kinds of wastewater discharged in the electroplating production process, including pickling wastewater, rinsing wastewater, passivation wastewater, brushing floor and plate wastewater, and wastewater generated by "running and dripping" caused by poor operation or management. The water quality and quantity of electroplating wastewater are related to the process conditions, production load, operation management and water use mode of electroplating production.
The common characteristics of electroplating wastewater are that the water quality is simple, the composition is not concise to master, which contains chromium, cadmium, nickel, copper, zinc, gold, silver and other heavy metal ions and cyanide and other toxic substances, can not be degraded by simple biochemical methods, some pollutants belong to carcinogenic mutagenesis of highly toxic substances, the physical and chemical treatment process is simple, the treatment cost is high, is recognized in the industry as a difficult treatment wastewater.
IIWeishengda environmental protectionZero-row process
In order to achieve zero discharge of this kind of electroplating wastewater, the commonly used zero discharge technology is to adjust and precipitate heavy metal wastewater, the effluent first enters the membrane system for treatment, the clean water is reused, and the concentrated water enters the evaporation system for desalination.
The detailed performance is as follows: after the electroplating wastewater is pre-adjusted pH, the appropriate flocculant and coagulant are selected for dosing and precipitation, the precipitate is treated as hazardous waste, and the supernatant enters the membrane system for treatment. The clean water produced by the membrane system can be directly returned to the production line, and the concentrated liquid needs to enter the evaporation device for further evaporation and concentration. After the concentrated crystallization process of evaporation and condensation, the desalinated water and concentrated slurry waste liquid are respectively, and the salt and part of the organic matter can be crystallized as solid waste treatment, and the desalinated water can be returned to the production system to replace the demineralized water for use. However, in practical application, on the one hand, due to the high organic content in the electroplating wastewater, the blockage of the membrane system often disappears. On the other hand, the heavy metal content of the wastewater after adjustment and precipitation fails to meet the standard, and the salt content after evaporation is judged to be hazardous waste, and the treatment cost is high, which causes trouble to the stable operation of the enterprise.
The electroplating wastewater combination process developed by Weishengda Environmental Protection can concentrate and crystallize the concentrated water at the back end of the membrane system, greatly reduce the amount of hazardous waste after treatment, reduce the cost of outsourcing disposal, and provide an effective solution for zero discharge of electroplating wastewater.
The process flow of zero discharge of environmental protection electroplating wastewater is shown in the figure below
Weishengda environmental protection electroplating wastewater zero discharge process.
IIICase Introduction
The client is a wholly U.S.-owned company, mainly involved in military aviation, automation, broadband communications, industrial equipment, Internet equipment, mobile**, wireless facilities. Electroless nickel and electroless copper wastewater is difficult to dispose of, and the original wastewater into the wastewater treatment system will lead to excessive discharge and high outsourcing costs. In order to better achieve zero discharge of wastewater, the customer finally chose the low-temperature evaporation crystallizer with a daily treatment of 5 tons of Weishengda Environmental Protection after comprehensive comparison of the disposal process on the market, and the waste liquid was reduced by more than 80% after the wastewater was treated, and the effluent quality was good, reaching the inlet standard. The moisture content of the concentrate is less than 18%, which meets the customer's requirements of no more than 20%, and the equipment runs stably, and there is no problem of fouling and pipe blockage.
The on-site lighting and disposal effect of Weishengda cryogenic evaporator.