Study On Electrocatalytic Oxidative Degradation Of Sulfonamides

Sulfonamides（SAs）isaclassofdrugswiththestructureof p-aminophenylsulfonamide,which has broad spectrum of antibacterial properties and is widely used in human medicine,animal husbandry,aquaculture and other industries.The extensive use of antibiotics has led to the proliferation of drug-resistant bacteria in the environment and the gradual increase of drug resistance,which is harmful to human health.Advanced electrochemical oxidation technologies（AOPs）are considered to be one of the most promising due to their wide application,simple operation,high degradation efficiency and environmental friendliness.With SAs as the research target,this study through electrocatalytic technology and electrocatalytic technology in collaboration with other methods,on part of the sulfa pollution existing in the environmental restoration research,so as to provide some reference for antibiotics pollution repair value.The main contents of the study are as follows:（1）In the parent material of sulfonamides antibiotics in water sulfanilamide（SA）as the research object,the effects of initial concentration,pH value,current strength,anode material,electrode spacing,electrolyte type and concentration of SA on SA degradation were investigated.Using cyclic voltammetry and salicylic acid radical capture research electrocatalytic oxidation degradation mechanism of action of SA,use of LC-MS analysis electrocatalytic degradation products of SA.The results show that SA meets the Langmuir-hinshelwood model in electrocatalytic oxidation and degradation wastewater,and the degradation rate of SA can reach 89.2%after 180min reaction under optimal parameters.The higher the initial concentration,current intensity and electrolyte concentration of SA in the reaction solution,the higher the electrode spacing is,the more conducive it is to the degradation of SA.The degradation efficiency is best when the anode material is titanium platinum-plated,followed by iridium tantalum and graphite electrode.The electrolytic efficiency of four electrolytes,Na₂SO₄,Na₂CO₃,NaCl and NaNO₃,was compared,and the degradation effect was as follows:NaNO₃>NaCl>Na₂SO₄>Na₂CO₃.Electrocatalytic oxidation degradation of SA were common function by the anodic oxidation directly and indirect oxidation process,the most direct electron transfer of SA molecules on the surface of the anode is the first step on the degradation reaction,and then into a solution with oxidizing substances produced by the electrolysis system in indirect oxidation,has finally been mine im into CO₂,H₂O and small organic molecules.（2）To be widely used in the production of livestock and poultry breeding between sulfamonomethoxine（SMM）as the research object,using electrocatalytic oxidation of collaborative CaO₂ SMM in livestock and poultry breeding wastewater degradation,comparing different SMM in the reaction system,the degradation effect of current density,CaO₂ dosing quantity,initial pH value,the influence of the waste water diluted multiples of SMM degradation,and COD in waste water and heavy metal removal effect.Results show that the single plus Fe²⁺,individual and CaO₂,CaO₂ and Fe²⁺,as well as individual electrocatalysis EC four system,reaction after120 min,the SMM degradation rate were 1.5%,13.6%,16.2%and 1.5%respectively,the degradation of collaborative CaO₂ oxidation catalyst system for the electric rate of 78.2%,show that the method can effectively remove the SMM in livestock and poultry waste water;The higher the current density,the better the degradation effect.The effect of acid condition was higher than that of alkaline.The lower the concentration of wastewater,the better the removal effect of SMM and COD is.Under the optimum conditions,the removal rate of COD can reach 66.1%.At the same time,the generated Ca（OH）₂ in the system can flocculate and precipitate with heavy metals in the waste water,so that it can be removed.The higher the amount of CaO₂,the better the removal effect.（3）To SMM high detection rate of sewage sludge as the research object,Uses electrocatalytic oxidation degradation of sludge in urban sewage treatment plants in the SMM,examine the influence of different current density on the degradation of the SMM,variety and quality is adding the different flocculants to SMM degradation and the effect of sludge dewatering properties indexes were measured at the same time.The results show that electrocatalytic oxidation can effectively degrade SMM in sludge,and the current density is 20 mA/cm² can be charged for 180 min,and the degradation rate of SMM can reach 52%.The higher the current density,the better the degradation effect of SMM,but the higher the current density,the lower the current efficiency.Adding the cationic polyacrylamide（PAM）and polyaluminium chloride（PAC）,3 kinds of polymeric ferric sulfate flocculant,SMM degradation rate of 66.8%,57.7%,66.8%,of not adding flocculant of sludge in the SMM degradation rate was 69.3%,that of the degradation of SMM slightly suppressed,PAM compared to other two kinds of flocculants to SMM degradation effects of smaller;Electrocatalytic oxidation and degradation of SMM in sludge can improve sludge dewatering performance.（4）The detection frequency is higher in the soil of 7 kinds of sulfa antibiotics as the research object,USES electric catalytic oxidation degradation,different current density and the effects of the soil and water ratio on the degradation of optimal electrode configuration,compare the old and new electrode device degradation effect of SAs.The results show that the soil than 3:1,current density 32 mA/cm² catalytic reaction was 6 h,SAs average degradation rate reaches 70.7%,the higher current density,soil and water ratio,the greater the electric catalytic oxidation degradation effect of SAs was better;The degradation efficiency of internal and external optimized electrode is obviously higher than that of the opposite electrode,which greatly improves the degradation efficiency and energy utilization rate of SAs and is economical and efficient.