The Research Of High Concentration Of Wastewater Containing Copper Treatment By Electrodeposition With Nitrogen

With the development of Industry, the processes of chemical industry, printing and dyeing, electroplating, non-ferrous metallurgy, non-ferrous metal mining, electronic materials rinse and dye production produce large amounts of copper-containing wastewater. If these copper-containing wastewater is not treated and discharged directly, it will not only cause the waste of resources and would cause great harm to the environment and human health.The main purpose of this paper is to choose a way to deal with or pretreatment the copper-containing wastewater and on this basis,recycle the available copper in wastewater.This article describes the sources and hazards of the heavy metal waste water and the research of treatment technology to the heavy metal wastewater in this stage. Integrate the pros and cons of the various approaches and the purpose of this research, we select the electrodeposition method ultimately. In the process of treatment with electrodeposition, Cu2+moves to the surface of the cathode, was reduced and deposed in the force of the electric field.It experienced a series of steps, such as the liquid phase mass transfer, pre-conversion, charge transfer and electron crystallization and so on.The method of electrodeposition can realize the treatment of wastewater containing copper and recycle the copper.It has the advantages of mature technology, simple equipment, small footprint, no secondary pollution.In this paper,I use the homemade electrodeposition device and the electrodeposition solution of manually configured copper sulfate.This paper studies the reaction mechanism of the electrodeposition process systematically and the impacts of the the electrode material, the groove voltage, electrode spacing, the initial concentration of the electrodeposition concentration, the initial pH value and other operating parameters to the electro-deposition effect for the best experimental conditions to the copper electrodeposition. Meanwhile,the paper analyzed the morphology of the electrodeposition copper for observing the specific process of copper crystals were precipitated in the surface on the cathode electrode from a microscopic point of view.The main conclusions of experiment are as follows:(1) Under the same experimental conditions, use aluminum as the cathode for electrodeposition is better, with the stainless steel plate comparison, when the electrolysis time is150min,the removal efficiency of Cu2+can reach94%.(2) Adjust the cell voltage is5V,6V,7V,8V,9V respectively. Found that with the increase of cell voltage, the removal efficiency of Cu2+continues to grow.Purged with nitrogen, when the electrolysis time is150min, the removal rate of Cu+can reach94%. However, when the cell voltage increased to9V, the electrolysis of water is vigorous, and the current efficiency is lower.(3) Under the same experimental conditions, adjust the plate spacing is10mm,15mm,20mm,25mm respectively.Because of nitrogen gas, when the electrolysis time is120min, the removal rate of Cu2+is95%,92%,87%,82%respectively. But when the plate spacing is less than10mm, the precipitation of dendritic copper contact each other and cause short circuit.it will impact the current efficiency of electrodeposition.(4) In the experimental concentration range, the higher initial concentration of Cu2+, the greater the final removal of Cu2+. With the reduction of Cu2+in solution, the removal amplitude of Cu2+decreases gradually,eventually flatten.(5) The pH of the bath can affect the conductivity and the precipitation of hydrogen.The removal of Cu2+decreases with the increasing of pH value. Purged with nitrogen, when the pH value is1.5and electrolysis time is120min,the removal rate of Cu2+can reach99%; when the pH value is4.5and electrolysis time is120min, the removal rate of Cu2+is only84%.(6) The copper obtained in the experimental that precipitated on the surface of the cathode is dendrimer by scanning electron microscope. Analysts believe that in this experiment conditions, the current density is bigger, electrodeposition reaction speed is higher and the vertical growth of grain on the surface of the cathode is faster.After the experimental study, the best results under our experimental conditions are:when the cathode is aluminum, the anode is a graphite plate, the groove voltage V =7V, the plate spacing is10mm, the Cu2+of initial electrodeposition concentration approximately is1000mg/L, the initial pH is3.5, the electrodeposition time is120min with nitrogen,the removal rate of Cu2+can reach95%.