Study On Treatment Of Piperidine Wastewater By Electrocatalytic Fenton-tubular Membrane Electrode

The chemical wastewater has the characteristics of high concentration,difficult degradation and strong toxicity,which makes the conventional biological treatment process difficult to operate stably,especially taking the nitrogen-containing heterocyclic ring as an example,such as pyrimidine,pyrazole,tricyclozole tetramethylpiperidine（TAD）,etc.the chemical stability is good,the biological treatment technology is difficult to solve.Therefore,many scholars use advanced oxidation technology to treat nitrogen-containing heterocyclic wastewater,and determine the feasibility of this kind of material treatment ideas.However,little research has been done on piperidine wastewater,especially on tetramethylpiperidine（TAD）.Therefore,electro-catalytic Fenton-tubular membrane electrode technology was used to treat the wastewater of tetramethylpiperidine（TAD）.Firstly,Ti/SnO₂-Sb tubular membrane electrode was prepared by sol-gel method,and its physical morphology（SEM,EDS,XRD）and electrochemical properties（CV,LSV）were characterized.The oxygen evolution potential of Ti/SnO₂-Sb tubular membrane electrode was1.84 V determined by the electrochemical property of LSV,and the simulated wastewater of tetramethylpiperidine（TAD）was studied,the optimal electrochemical oxidation parameters of tetramethylpiperidine（TAD）simulated wastewater were determined as follows:p H=3,current density=10m A·cm^-2,flow rate 80 ml·min^-1,initial concentration of tetramethylpiperidine（TAD）:100 mg/L.Furthermore,the oxidation of simulated wastewater containing tetramethylpiperidine（TAD）was studied by electro-catalytic Fenton-tubular membrane electrode technique,the optimum Ti/SnO₂-Sb tubular membrane electrode current density is 10 m A·cm^-2,the dosage of hydrogen peroxide is m（H₂O₂）/m（COD）=1.5,and the actual ratio of Fenton is n（H₂O₂）/n(Fe²⁺)=8.On the basis of the above,the oxidation of low concentration practical wastewater containing tetramethylpiperidine（TAD）and high concentration practical wastewater was studied,and it was found that the COD removal rate of low concentration wastewater could reach 60%,the biodegradability（B/C ratio）of wastewater was improved from 0.12 to 0.26.At the same time,under the conditions of HRT16h,m（H₂O₂）/m（COD）=1,n（H₂O₂）/n(Fe²⁺)=8,the removal rate of COD of high concentration wastewater can reach 48%.On the basis of the above research,this paper combined electro-catalytic Fenton-tubular membrane electrode oxidation technology with biochemical process to study the application of piperidine wastewater treatment.The results show that the electro-catalytic Fenton-tubular membrane electrode system can remove50-60%COD,and the effluent can enter the biochemical section,the concentration of COD,NH₃-N and TN decreased from 3000 mg·L^-1 to 300-400 mg·L^-1,from 200-300mg·L^-1 to 10 mg·L^-1 and from 300 mg·L^-1 to 50 mg·L^-1 respectively.In this study,the system of treating piperidine wastewater by electro-catalytic Fenton-tubular membrane electrode technology was constructed.At present,this technology has been applied in engineering on a large scale,which provides a new idea and technical support for the treatment of nitrogenous heterocyclic wastewater.