Study On The Simultaneous Adsorption Of Metal Ions And Anions Of Metal Salts And Antibacterial Properties Of Modified Silica Gel

In this research,silica gel was used as the substrate and three adsorbents SG-H2L1,SG-H2L2 and SG-H2L3 were prepared by using amino-modified silica gel with 5-bromosalicylaldehyde and its derivative and applied to the adsorption of metal ions and anions in the simulated wastewater.The characterization analysis was performed through FT-IR?SEM?BET?EPR?TGA and the adsorption behavior of cations and anions in metal salt solution was studied.The adsorptive capacity of metal ion and anion were detected by an Inductive Coupled Plasma Emission Spectrometer(ICP)and ion chromatography(ICS)respectively.The adsorption properties of adsorbents to metal ions and anions were investigated by pH value,temperature,different cation and anion competitive adsorption.About antibacterial activity of modified silica gel,three silica gel antibacterial agents SG-QAs,SG-QA12 and SG-QA16 were prepared by using amino-modified silica gel with quaternary ammonium salts in this study.The modified silica gel antibacterial agents were characterized by FT-IR,EA,TGA and XPS.The antibacterial behavior of SG-QAs,SG-QA12 and SG-QA16 on Escherichia coli and Staphylococcus aureus were evaluated by the use of plate count method.By the above-mentioned research,we can get the following conclusions:(1)The absorptive capacity of SG-H2L3 to metal ions and anions was higher than SG-H2L1 and SG-H2L2,which indicate that SG-H2L3 has synergistic effect on the adsorption of metal ion and anion;when the metal ions of Cu2+,Ni2+,Mn2+,Co2+ and Cd2+ coexist in the same solution,these adsorbents were only absorbed Cu2+ when the anions of SO42-,Cl-and NO3-were present simultaneously,only absorbed SO42-and NO3-and the absorptive capacity is SO42->NO3-;The adsorption behavior of Cu2+ and SO42-onto SG-H2L3 were fitted to Langmuir isotherm model and pseudo-second-order kinetics model.The maximum adsorption capacity for Cu2+and SO42-was 54.14mg/g and 75.13mg/g respectively;Thermodynamic analysis results show that the adsorption processes of SG-H2L3 on Cu2+ and SO42-is a endothermic spontaneous process.(2)The amino-modified silica gel SG-(NH)2-NH2 has no antibacterial activity against S.aureus and E.coli;The antibacterial activity of SG-QAs,SG-QA12 and SG-QA16 on S.aureus were stronger than E.coli and the sequence of antibacterial activity was SG-QA16>SG-QA12>SG-QA8;When added 0.4mL(1×108CFU/mL)E.coli bacterial suspension,the MIC values of SG-QA8,SG-QA12 and SG-QA16 against E.coli were 20,16 and 12 mg/mL respectively and added 0.5mL(8.5×1OBCFU/mL)S.aureus bacterial suspension,the MIC values of SG-QA8,SG-QA12 and SG-QA16 against S.aureus were 2.4,1 and 0.8 mg/mL respectively.