Ultrasound Enhanced Electrochemical Oxidation Of Chloramphenicol Wastewater With Titanium Suboxide Anode

With the acceleration of urbanization in China,the amount of waste water is increasing.faster and faster in our country,and the amount of waste water produced is increasing.This paper is based on the research of wastewater treatment in pharmaceutical industry.Ultrasound electrochemical oxidation has been widely concerned in the field of antibiotic wastewater treatment for its high efficiency,no secondary pollution and low energy consumption.At present,there are two crucial points for the industrialization of electrochemical oxidation technology,that is to find an efficient and stable electrode material firstly,and effectively improve the mass transfer and diffusion efficiency forpollutants degradation.In this paper,a combined system of ultrasound enhanced electrochemical oxidation was constructed to purify chloramphenicol wastewater using titanium oxide anode for its excellent electrochemical properties.Based on the principle of mass transfer and diffusion,the feasibility of degradation of chloramphenicol?CAP?pharmaceutical wastewater by electrochemical oxidation assisted by ultrasound was investigated.The titanium oxide anode was characterized by scanning electron microscope?SEM?,X-ray diffraction?XRD?and X-ray photoelectron spectroscopy?XPS?,which proved a honeycomb porous structure dominated by macroporous and mesoporous,main components for Ti and O and the crystal phase for mostly Ti₄O₇.The EIS test results showed that the conductivity of titanium oxide was very similar to that of carbon cloth.However,the internal resistance of charge transfer is much smaller than that of carbon cloth.The CV test showed that titanium oxide had high electrochemical stability.At the same time,the calculation of the mass transfer rate constant under the condition of ultrasonic assistance showed that the horizontal convection of solute to the anode surface is enhanced by increasing the ultrasonic power.The abundant pore structure,excellent electrochemical performance and unique and excellent performance of titanium oxide materials,which are different from other traditional electrodes,provide better conditions for the rapid and effective degradation of organic pollutants in the electrochemical process.Based on the characteristics of high conductivity,good electrochemical activity and good stability,titanium oxide used as anode during electrochemical oxidation was expected to enhance removal efficiency.The effect of titanium oxide on the treatment of simulated chloramphenicol wastewater was investigated.The results showed that optimal operation conditions were20 mg·L^-1,the optimal electrolyte solution,ultrasonic power,current density and pH conditions were 0.05 mol·L^-1sodium sulfate solution,150 W,20 mA·cm^-22 and pH=5,respectively.The maximum removal rate of CAP can reach 100%,and the reaction energy consumption is low.The results of degradating actual pharmaceutical wastewater with anion coexistence showed that the COD and chroma in the delete effluent could reach the discharging delete within 2.5 h,with mineralization rate of 66.70%,and the energy consumption of 120.98 kwh·kg^-1.At the same time,it has low energy consumption,that is,ultrasound assisted using titanium oxide can realize the deep purification of practical CAP wastewater.concluded that the way of degradation of chloramphenicol by electrochemistry enhanced with ultrasound was:chloramphenicol?amino product?amino primary dehydration product?amino secondary dehydration product.The toxicity of CAP was removed in electrochemical system to provide conditions for subsequent degradation of CAP reduction products.The results showed that CAP was eventually oxidized to carbon dioxide,nitric acid,hydrochloric acid and water.