Technology Research On How To Make The Electroplating Wastewater’s COD Content Reach The Standard

Currently plating has been widely used in various industries, with the scale electroplating industry continues to grow, electroplating wastewater corresponding sharp increase in emissions, which electroplating wastewater containing acid, alkali, cyanide and hexavalent chromium, cadmium, copper, nickel, zinc and other heavy metal contaminants, toxicity is very large, and serious harm. Therefore, people are constantly looking for ways to reduce the dangers of electroplating wastewater, reducing their emissions, thereby promoting the sustainable development of electroplating industry. In this thesis, through a variety of chemical treatment of wastewater, looking for the best electroplating wastewater treatment method, and by changing the control parameters of various methods to determine the optimum process parameters, to promote the development of electroplating wastewater treatment processes and applications, providing important theoretical basis.In the course of the experiment using precipitation method, Fenton method, hydroxide precipitation+Fenton method, UV/O3law hydroxide precipitate+UV/H2O2methods such as electroplating wastewater.The results showed that treatment with hydroxide precipitate electroplating wastewater, the optimum pH was5.0, but COD, Nickel and copper ions still can not meet the standard requirements.By Fenton Process wastewater, in FeSO4.7H2O with H2O2dosage was0.99g/L and120mg/L when, COD concentration to meet emissions requirements,Cu2+and Zn2+concentration is less than detection line, Ni2+concentration can not meet emission requirements. Continue to increase the dosage, Ni2+concentration is still unable to meet emission requirements.Hydroxide precipitation+Fenton method using electroplating wastewater, the first adjusting the pH to5.0, still0.5h, and the supernatant, and then FeSO4.7H2O with H2O2dosage was1.31g/L and160mg/L, the COD and heavy metal ions are in compliance with emission standards.UV/O3method in the treatment of electroplating wastewater process, due to the aeration will produce a lot of foam, it does not apply to ozone oxidation treatment of electroplating wastewater.By hydroxide precipitation+UV/H2O2electroplating wastewater treatment, the dosage of H2O2was240mg/L, reaction time was0.5h, the reaction at pH9.5, COD, and heavy metals are in compliance with emission standards. Biological activated carbon treatment by hydroxide precipitation+Fenton treatment and by hydroxide precipitation+UV/H2O2treatment of electroplating wastewater, the residence time of1h, gas-water ratio of400:1, the electroplating wastewater COD a certain treatment effect, for COD in60mg/L of about wastewater, COD removal efficiency of biological activated carbon can reach30to40%.