The Preparation Of Sodium Alginate Composite Material And Its Adsorption Performance For Tetracycline

In the mid-20 th century,antibiotics were widely used.During this half century,we have continuously explored that antibiotics are widely used to treat diseases such as humans and livestock.However,the environmental problems caused by antibiotics are becoming more and more serious,and the water pollution caused by antibiotics produced by animals is attracting worldwide attention.Scientists around the world are looking for an efficient way to remove antibiotics from water,such as chemical coagulation,photocatalytic degradation,biological treatment,membrane separation,adsorption etc.These methods have their own unique advantages,and there are more or less deficiencies.In social practice,the practical application value of these methods has been shown in varying degrees.Among them,the adsorption method,which has the advantages of low cost,short time consumption,high yield and easy recovery,has opened up a broad new world in the field of purification of water-soluble antibiotics.Among them,environmentally friendly materials mainly composed of natural polymer materials are used as adsorbents.Because of its wide source of materials,good biocompatibility,non-toxicity,low price and other characteristics,it has been used in the field of sewage treatment,and good results have been obtained.Sodium alginate is a polysaccharide of natural organic polymer,a large amount of free hydroxyl and carboxyl groups are present in the molecular chain of sodium alginate.Sodium alginate can crosslink with most of the divalent metal cations or small molecule crosslinkers.A three-dimensional network gel is formed,and a composite adsorbent can also be formed with graphene oxide,humic acid,chitosan or the like.Citric acid is a compound of tricarboxylic acid,which has good water solubility,is easy to form complex with metal cation after being ionized in water,but the complex formed is difficult to separate from the aqueous solution,so that the citric acid needs to be compounded with other materials to form a water-insoluble.In this paper,copper alginate gel wire and copper alginate / citric acid gel wire were prepared,and the adsorption properties of tetracycline were investigated and studied.The alginate was processed by a wet spinning technique,and the aerogel was prepared by a vacuum freeze-drying apparatus.In order to further understand its chemical composition and surface structure,scanning electron microscope(SEM)and Fourier transform infrared spectroscopy(FTIR)were used to detect the chemical composition and surface structure.the experimental conditions was strict control,the experiment was repeated to explore the specific situation of the adsorption of tetracycline by copper alginate.The adsorption process was simulated by adsorption kinetics.It is known from the calculation results that the adsorption process conforms to the Pseudo-second-order equation.The adsorption of tetracycline isotherm showed that the adsorption of tetracycline by copper alginate was more in accordance with the Langmuir equation,and the maximum adsorption capacity of tetracycline was 215.15 mg/g.The thermodynamic properties were studied by the theory of adsorption thermodynamics.The data show that the adsorption of tetracycline by copper alginate is more likely to occur spontaneously at higher temperatures.The copper alginate/citric acid was prepared by wet spinning and freeze drying,and its surface morphology and molecular structure were analyzed by various characterization methods.The interference of different external conditions on the adsorption of tetracycline by copper alginate / citric acid gel wire was tested.The whole process of the experiment was simulated by the adsorption kinetics model,and the experimental process was more in line with the Pseudo-second-order equation.The adsorption isotherm of tetracycline shows that the process of tetracycline attachment to gel wire follows langmuir equation,and the maximum adsorption capacity of tetracycline is 299.5 mg/g.The adsorption thermodynamics of tetracycline adsorbed by copper alginate / citric acid showed that the adsorption of tetracycline by copper alginate / citric acid could be carried out spontaneously and the reaction was endothermic.