Preparation Of Composite Nanofibrous Films For Dynamic Adsorption Of Metal Ions Supported On Layer-by-layer Assembly

In recent years,the water pollution has become more and more serious,due to the industrial wastewater and domestic wastewater.And the industrial wastewater was mainly from food industry,pharmaceutical industry,petro-chemical industry and so on.Just because of this,it became an important task for sewage treatment and various water treatment technologies developed rapidly.Among them,adsorption technology was considered to be the most effective treatment technology.And adsorption technology has generated great interest because of lower operation pressure,low energy consumption and convenient operation.However,characteristics of adsorbing membranes are the core part of adsorption.Whether the effects of the adsorption are ideal or not depends greatly on characteristics of adsorbing membranes.Therefore,the preparation and characterization of adsorbing membranes are our research emphasis.Electrospinning technology is the use of making the polymer solution or melt to bring high-voltage static electricity with high voltage electric field.And under the impact of the electric force,the solution need to overcome the surface tension of the spray to form a thin stream deposited on the substrate(non-woven fabrics,aluminum foil or other fabric).After evaporation of the solvent,the polymer nanofibers will be formed.Layer-by-Layer(Lb L)assembly technology a Fiber modification method which combines two polyelectrolyte(PEL)with opposite electrical resistance layer by layer coated on a certain substrate to form a fibrous layer.In this paper,we utilized electrospinning combining with Lb L assembly for preparing two different nanofibrous composite films.The main idea was to deposite chitosan and sodium alginate onto the nanofibrous substrate by Lb L.As-prepared composite film not only has a dense interception,but also some extra water passages because of hydrophilic substance.A scanning electron microscope(SEM)was utilized to investigate the nanofibrous films and the structure of the Lb L films.A fourier transform infrared spectroscopy(FT-IR)was used to analyze the substances adhered to the film.A inductively coupled plasma spectrometer(ICP-AES)was utilized to determine the concentration of heavy metal ions.The results showed that the preparation of composite fiber membranes have been successfully modified.For the removal of metal ions,as-prepared composite films had a significant effect.For ordinary metal ions removal,the most efficient ion was Al³⁺,and for heavy metal ions removal,the most efficient was Ba²⁺.