Preparation Of A Novel Fe-Cu@C Micro-electrolysis Ceramsite And Its Degradation Of Nitrobenzene Wastewater

In recent years,the discharge of nitrobenzene wastewater has gradually increased.It has high organic load,high color,high acidity,low biodegradability and toxicity.Nitrobenzene wastewater is usually high-salt wastewater,and most water treatment technology is difficult to have a good treatment effect on it.Therefore,it is of great significance to study the treatment process of nitrobenzene wastewater.Micro-electrolysis technology treats nitrobenzene by reduction,and has a good treatment effect on nitrobenzene wastewater.However,the traditional micro-electrolysis technology faces two problems:easy hardening and passivation during operation;it has good treatment effect only under acidic conditions.In view of the above problems,a new ternary micro-electrolysis ceramsite was prepared in this study.The treatment effect of this material on nitrobenzene was investigated,and the degradation mechanism of nitrobenzene was explored.First of all,copper-coated carbon powder(Cu@C)was prepared by electroplating on sludge carbon plate.The effects of copper ion concentration and current density on the morphology,plating rate and current efficiency of the coating were investigated,and Cu@C was tested by SEM-EDS and XRD.The results show that when the concentration of copper ion is 0.10 mol/L and the current density is 10 m A/cm~2,the plating time is proportional to the weight of the coating,and the coating and the substrate are tightly bonded.Then,the sintering conditions were determined by thermogravimetric analysis of drilling mud.A new ternary micro-electrolysis ceramsite(Fe-Cu@C ceramsite)was prepared by using Cu@C,scrap iron and drilling mud as raw materials.Based on the degradation rate of nitrobenzene,the best copper plating rate was screened.The effects of initial concentration of nitrobenzene,solution p H and aeration conditions on the degradation of nitrobenzene were investigated by single factor experiment.Then the continuous operation performance of the material was investigated under the optimal operating conditions.Under the conditions of nitrobenzene concentration of 100 mg/L,stable solution p H=3 and nitrogen aeration,Fe-Cu@C ceramsite with 5%copper plating ratio has the best treatment effect on nitrobenzene wastewater,and 97.67%nitrobenzene can be removed within 90 min.Moreover,the material also showed good continuous operation performance,and the removal rate of nitrobenzene was still higher than 80%when treating the fifth batch of water samples.After pickling,the performance of the used Fe-Cu@C ceramsite recovered well.The Fe-Cu@C ceramsite before and after use was characterized by SEM-EDS,XRD and XPS.The results show that a large amount of iron oxides were attached to the surface of the ceramsite after use,Fe~0 is oxidized to Fe OOH,and a very small amount of Cu~0 is also oxidized.The degradation mechanism of nitrobenzene was studied by CV and GC tests.It was found that nitrobenzene was first reduced to nitrosobenzene,then reduced to hydroxyaniline,and finally reduced to aniline.Aniline was mainly removed by flocculation.