Preparation Of The Polyacrylonitrile-based Composite Nanofibers And Its Application For The Methylene Blue In Industrial Pharmaceutical Wastewater

With the rapid development of the pharmaceutical industry,pharmaceutical wastewater is considered to be one of the biggest sources of water pollution.It is estimated that annually 70,000 metric tons of pharmaceutical intermediates are discharged into wastewater in the worldwide in the fields of pharmaceutical industry.Furthermore,many pharmaceutical intermediates and their incomplete degradation products have complex constitution,high chemical oxygen demand(COD)level,deep and long-lasting color,and high toxicity,which cause annoyance to the aquatic biosphere.Among many materials,electrospun nanofibers have attracted more and more attention due to their high surface area and good adsorption properties.It has also shown a good application prospect in the field of pharmaceutical industrial wastewater treatment.Electrostatic spinning technology requires simple equipment,easy operation,process control and other advantages,is an effective method for the preparation of one-dimensional functional nanofiber material.In this study,a novel electrospun nanofibrous composite was prepared from polyacrylonitrile and well-dispersed oxide nanoparticles containing TiO2,Ag3VO4.The nanoparticles incorporated into the nanofibers can endow the composite with photocatalytic and antimicrobial ability.The morphologies and structure of the nanofibers were characterized by Fourier transform infrared(FT-IR),scanning electron microscopy(SEM)and X-ray diffractometer(XRD).The thermal properties of composite nanofibers was investigated by thermogravimetric analyzer(TGA).To investigate the adsorption properties of methylene blue by composite nanofibers and its mechanism,batch experiments were carried out with original and chemical modification,solution pH,temperature,dosage,contact time and initial concentration of the contaminant.Almost complete MB removal was observed within 120 min at room temperature 25 ℃ with a very high maximum retention capacity of 155.4 mg g-1.What’s more,kinetics analysis indicated that the dye adsorption by electrospun nanofibrous composite agreed well with the Langmuir isotherm model and pseudo-second order model compared to other models applied in the study.In addition,the nanofibrous composite adsorbent could be easily separated from contaminant solutions and showed high reusability for numerous repeat cycles.This study shows that composite nanofiber membranes prepared by electrospinning have good antibacterial,photocatalytic degradability and high adsorption performance under the synergetic effect of embedded nanoparticles,thus indicated a great potential for pharmaceutical intermediate pollutants removal in the wastewater treatment.