Study And Application Of New Technology For Treatment Of Plastic Electroplating Cu/Ni/Cr Wastewater

Plastic electroplating is a method adopting conventional electroplating after plating metal on the surface of plastics(commonly used ABS / PC,ABS)with the amalgamation of chemical and electrochemical methods.At present,electroplating technology is widely used in machine manufacturing,light industry,electronics and other industries.It’s well known that the composition of plating wastewater is complex,and the pollutants can be divided into two categories: inorganic pollutants and organic pollutants.The water quality varies greatly,the pollutants in plating wastewater are various,and the COD variation coefficient is large.Based on the process optimization of neutralization precipitation method and chemical reduction method,the technological parameters of copper,nickel,chromium,COD,ammonia nitrogen and wastewater treatment in plastic electroplating were studied in this paper.The influence of pollutant composition in plastic electroplating wastewater of Automobile decorative parts on the difficulty of wastewater treatment was studied.The method and effect of recycling and reusing the cleaning water of plastic electroplating to the production line were studied.The economy and safety of various methods in the treatment of plastic electroplating wastewater were evaluated.The environmental risk and production cost of plastic electroplating enterprises such as automobile decorative parts were reduced and the wastewater was optimized.The research results are as follows:1.The treatment of wastewater containing hexavalent chromium plating is studied empHatically.pH value is controlled at 2.2,hexavalent chromium reduction potential is about 150,and the concentration of wastewater containing hexavalent chromium will pass through.Constant change,not constant value,hexavalent chromium reductant input will exist lag pHenomenon,so the reductant(sodium bisulfite)input is 1.4-1.5 times the theoretical value,reaction time is 30 minutes,accurate input according to the flow of different systems through experimental fine-tuning.2.The technological parameters of removing ammonia ion and nickel are as follows: ammonia nitrogen stripping process is selected,pH value is controlled at about 11,after stripping,it is mixed with electroplating nickel wastewater for precipitation reaction,PH value is about 9.5-10,precipitation is followed by heavy metal capture,and finally coagulation sedimentation.3.The removal of COD in copper-containing wastewater is mainly studied.The main source of COD in plastic electroplating is degreasing and cleaning water which is pretreated by advanced pretreatment method.The electrocoagulation pretreatment was carried out,and then the electrocoagulation pretreatment was mixed with other comprehensive water for conventional sedimentation reaction,pH 7-9,and finally coagulation sedimentation.4.It is the basic requirement of environmental protection law to discharge the wastewater up to the standard after treatment,but energy saving and emission reduction in heavy pollution industry is the ultimate research direction of technicians and the highest goal of national development.The recycling of wastewater with low concentrations of pollutants is another result of this study.