Study On Removing Tetracycline And Hydroxylmethylfurfural From Honey

Honey, which was the nature nutriment, consisted of over 65% reduce sugar. Stored overtime or treated overheat, reduce sugar converted to hydroxymethylfurfural(HMF) easily, which would influence the taste and appearance of honey. Meanwhile, beekeeper often fed antibiotics such as tetracycline(TC) to bees, which would bring rudimental antibiotics in honey. So the adsorption method was studied to remove the HMF and TC using granule active carbon(GAC).Firstly, the methods of determining the contents of HMF and TC were studied. The bi-wavelengh ultraviolet method possessed high accuracy and recoveries were 84% above. It was applicable to simulation solution. In order to avoid the disturbance, derivative spectrophotometric method was fit to determine HMF, recoveries were over 94%.The studies demonstrated relative face area, iodine value and methylene blue value had the liner relationship with the adsorption capacity of GAC to HMF and TC.The mechanisms for LH-15 GAC to adsorb HMF and TC from honey in the adsorption kinetics and thermodynamics view were studied. Kinetics study demonstrated that the optimum pH was 4 to obtain the biggest adsorption velocity. The adsorption processes were accord with the pseudo second-order equation for TC and the pseudo first-order equation for HMF. The key dominate steps were liquid diffusion. The thermodynamics results showed that the equilibrium adsorption isotherms were accord with Langmuir model. The processes belonged to the physics adsorption.The surface chemical properties of GAC modified by nitric acid had significant influence on its adsorption performance. The purpose of studies lied in making clear the effect of modification factors, physical and chemical properties, which would influence the adsorption capacity. The results showed that the modification temperature was the main factor influencing the adsorption performance. The best conditions were obtained: nitric acid concentration was 25%, modification temperature was 30℃, modification time length was 6h. Meanwhile, the results demonstrated that the process was the effects the physical adsorption and chemical adsorption to adsorb TC on modification GAC, and the main effect was physical adsorption to HMF...