Research On Treatment Of Electroplating Wastewater With Carbon Membrane And Coupling Technology

The electroplating process wastewater treatment system of an automobile brake system production plant in Dalian can only remove metal ions,but cannot effectively remove organic matter in wastewater.Two sets of wastewater treatment processes are designed for different treatment units of the factory wastewater treatment workstation to remove metal ions and organic matter in the wastewater to achieve the purpose of direct discharge.?1?The content of organic matter in the waste water from the outlet tank of the waste water treatment station exceeds the standard,a coupling process of electric Fenton oxidation and carbon membrane filtration was designed to solve this problem.Electro-Fenton oxidation is used as a pretreatment unit,and carbon membrane filtration can be further processed.The research contents are as follows:First,the optimal conditions for the treatment of organic matter in wastewater by electro-Fenton oxidation was studied.The effect of working voltage,pH value,mass ratio of H₂O₂ and FeSO₄ and treatment time on the removal rate of organic matter was studied under the combination of titanium plate as anode and carbon rod as cathode,the results show that electric Fenton oxidation can be used as a pretreatment unit for organic matter pretreatment.Under the conditions of voltage 2V,pH=3-4,mass ratio of H₂O₂ and FeSO₄ of 5,and treatment time of 1h,the removal rate of organic matter can reach 71.6%.Then do the depth of treatment using the carbon membrane,when the speed of the peristaltic pump is 75 r/min,the average removal rate of organic matter in the wastewater is 90.5%,and the concentration can be reduced to 36 mg/L at the lowest,which meets the national discharge standard.?2?In order to solve the problem that the content of metal ions and organic matter in the wastewater in the raw water filtration tank exceeds the standard,a coupling process of electro-flocculation precipitation and electrochemically assisted carbon membrane filtration was designed.The electric flocculation and precipitation process replaces the original chemical flocculation and precipitation to remove Zn²⁺in wastewater.The electro-assisted carbon membrane filtration process can oxidatively degrade organic matter in wastewater.The research contents are as follows:First,explore the best conditions for removing Zn²⁺by electro-flocculation precipitation.Both the anode and cathode are aluminum plates,and the effects of electrical conductivity,current density,plate spacing,and reaction time on the removal rate of Zn²⁺are studied.The experimental results show that the cationic polymer produced in the electrolysis process can effectively settle the metal ions in the wastewater,and electro-flocculation precipitation can be used as an alternative process for chemical flocculation precipitation,which can reduce the concentration of Zn²⁺and reduce the use of polyacrylamide.The Zn²⁺concentration in the wastewater was 0.5 mg/L and the removal rate was 97%at a conductivity of 4.60 s/m,a current of 1.5 A,a plate spacing of 2 cm,and a treatment time of 10 min.Secondly,based on the electro-flocculation precipitation process,an electrochemically assisted carbon membrane was used to remove organic matter in wastewater,and the effects of different initial concentrations,voltages,pH values,peristaltic pump speed,and conductivity on COD removal rate were studied.The optimal treatment conditions were determined.The carbon membrane was set as anode,the titanium plate as cathode,the initial COD concentration was 100 mg/L,the voltage was 2.5V,pH=7,the peristaltic pump speed was 75 r/min,and the conductivity was 6.26 s/m,under these conditions,the surface of the carbon membrane produces the most active oxidizing substances and has the strongest oxidative degradation ability to organic matter.The concentration of COD in the wastewater can be reduced to54mg/L and the removal rate is 47%.