Study On The Treatment Of Heavy Metals In Sludge By Magnetization Electrokinetic Method

Sewage treatment plant sludge contains organic matter,nitrogen,phosphorus,potassium and other nutrients,but also contains Cd,Pb,Zn and other environmental pollution caused by heavy metals.The removal of heavy metals from sludge can be used for agricultural purposes.As a kind of in-situ remediation technology,the electrokinetic method has the advantages of reusing and treating heavy metal pollutants.However,the electric current process under the applied magnetic field can greatly enhance the removal efficiency of some metals.Therefore,this paper explores the influence factors of removing heavy metals in sludge by electro dynamic method and magnetization electric method,in order to further improve the removal efficiency of heavy metals and optimize the removal of heavy metals in sludge.The research content is divided into two parts:the first part of the removal of heavy metals in sludge explore electric power law factors,including voltage,electrolysis time,initial pH value,whether the sludge circulation,mixing sludge,electrolyte cathode electrode material and electrode area;The second part is to explore the influence factors of the removal of heavy metals from sewage sludge by magnetization electric method.In the electric power method,the removal rate of heavy metals in the sludge can be effectively enhanced by prolonging the electrolysis time,enhancing the electrolytic voltage,reducing the initial pH value of the sludge,controlling the pH value of the cathode electrolyte,stirring the sludge without increasing the area of the electrode plate.Among them,the initial pH value of sludge is the decisive factor to control the removal rate of heavy metals.The experimental results show that the initial pH=3 of the sludge heavy metal removal rate reaches a maximum at Cd and Pb,the removal rate of Zn were 85.77%,31.14%,85.36%,the residual amount of heavy metals are in conformity with the provisions of the standard of sewage sludge.Electric magnetic method can effectively optimize the removal efficiency of heavy metals,when the magnetic field is 9.5mT,Cd and Zn removal rate is greater than the removal rate of sludge pH=3 when the initial electric power law,at Cd,the removal rate of Zn was 96.62%and 88.84%.However,the removal rate of Pb was not significantly improved by magnetization electric method.