Preparation Of Iron-Carbon Composites And Application On The Removal Of Sulfonamides Antibiotics From Water

Sulfonamides residues in the environment can affect a virtuous cycle of the whole ecosystem,will eventually harm to people's health.Since most of the sewage plants in China do not have the technique to remove SAs pollutants in an extensive and effective way,the search for an economic and effective of removal becomes a great necessity.The improvement of the adsorptivity of adsorbent by loading metallic compound now attracts increasing attention.The study intends to turn biochar into a new adsorbent that can offer any benefit in removing SAs by loading metallic compound in it and discuss the adsorbability of the new adsorbent under different conditions,thus providing a theoretical basis for the removal of SAs pollutants in domestic and breeding wastewater.(SA)and(SD),the two common SAs in the water,are research subjects in this article.We use biochar as adsorbent to find out its adsorption laws against SAs by static adsorbent experiment in laboratory under diverse conditions with different particle diameters,the initial adding quantity,initial concentration of antibiotic,adsorption time,initial pH,temperature to study their effects on SAs adsorbability of biochar.Then we use charcoals as immobilization matrix to prepare iron carbon composites and study how the methods and conditions of preparation for iron carbon composites affect the removal of SAs in the water.The main research contents and results are as follows:1.Through adsorption and removal experiment by using biochar bamboo charcoal and charcoal in wastewater,it turns out that biochar can adsorb SAs in the water.The adsobability and biochar particle diameters are inversely related: the smaller of biochar particle diameters adsorb more SAs The adsorbability of charcoal is better than that of bamboo charcoal.the result shows that the charcoal's adsorption of SD and SA can reach equilibrium within 12 h.The adsorption rate of SD and SA increases with the increase of the initial adding quantity,but the amount adsorbed on the unit decreases on the contrary.Charcoal can completely adsorb SA with initial concentration within 10 mg/L.As the concentration becomes stronger,the adsorption of SA and SD decreases.The max adsorption of SA can reach 0.52 mg/g under the concentration of 40 mg/L while SD can reach 0.18 mg/g under 20 mg/L and then adsorption diminishes gradually.Charcoal's adsorption of SA is better than SD.the adsorption and removal effect of SA and SD is better by charcoal was better under acid conditions than that of under neutral and alkaline conditions.By applying isothermy equation of Langmuir and Freundlich to the adsorption of SA and SD,the fitting result shows that the adsorption process of the two antibiotics ismore according with Freundlich model.Temperature should be best controlled at 25°C during the adsorption process.The kinetics fitting result for charcoal's adsorption of SA and SD shows that its adsorption process follows quasi-two-levels reaction kinetics and chemical reaction occurs during the process.2.We use charcoal as immobilization matrix with three preparation methods to immobilize hydrous iron oxide to prepare iron carbon composites,thus studying how preparation conditions affect adsorbability and characterizing iron carbon composite.It turns out that that the best way to remove of SA and SA is iron carbon composite that is prepared by vacuum rotary curing method.The best preparation condition is to mix saturating Fe(NO3)3 solution and charcoal with mass ratio 0.224:1 and then need to be cured at 60? for 9h in vacuum rotary evaporator.iron carbon composite is much better than charcoal in remove of SA and SD,when the inputs is 10 g/ml,charcoal's removal of SA and SD are 54.92% and 12.01%,iron carbon composites can completely remove SA and SD.Iron carbon composites conforms to the pseudo-first-order kinetics model,and its removal of SD is better than SA.3.Within the scope of this study,iron carbon composites can completely adsorb SA and SD with concentration within 25 mg/L.As the initial concentration becomes stronger,the removal rate of SA and SD decreases.Under weak-acid condition,iron carbon composites can get the best results in remove of SA and SD.But it can get the worst effect in alkaline condition.Na+ and Cl-have little effect in remove SA and SD for iron carbon composites.4.The characterizing results show that surface of iron charcoal 6.5 times than that of the charcoal with iron content of 11%.By scanning electron microscopy,we see that iron oxide can solid to charcoal surface.The analysis of XRD shows that the graphitization degree of iron carbon composites reduced.Iron substance solid to charcoal surface in the form of noncrystal hydrous iron oxide.Through the liquid chromatogram,we can deduce that iron carbon composites in removing SA and SD is the synergy of physical adsorption and chemical explanation,and it will generate understanding products in the process of reaction.