Preparation And Application Of Iron-carbon Composite Based On Humic Acid

Carbon materials have diverse structures and unusual properties due to the electronic arrangement,bonds and modes of carbon atoms,so it has a wide variety of applications in many fields.Carbon composites impoved the shortcomings og single carbon materials,such as low purity and poor performance,and make carbon materials more widely used,especially in the treatment of dye wastewater.Iron-carbon composites(Fe-C/HA)were prepared by high temperature solid state redox method using HA and Ferric salt(SF)as raw materials.The Fe-C/HA was prepared under different conditions of reaction temperature,heating rate,reaction time,HA and SF mass ratio may influence the removal rate of Congo red(CR),so we discussed and determined the optimal preparation conditions by using the removal rate as an evaluation index.The characterization of Fe-C/HA was carried out by means of SEM,XRD,BET,TG-DSC and FT-IR.We explored the the influences of Fe-C/HA dosage,temperature and pH on the removal rate of CR and determined the optimal adsorption conditions.Finally,the mechanism of removal of CR by Fe-C/HA have been discussed.Results show that the optimal condition for preparing Fe-C/HA is 300℃,3℃/min,3h and mass ratio HA:SF=1:2.The Fe-C/HA is made up of multilayer layered network interconnection structure linked by hydroxyl bridge and oxygen bridge network interconnection structure.The BET analysis results show that the specific surface area of Fe-C/HA is 59 m~2/g,the pore volume is 0.15 cm~3/g and the pore size distribution is around 3.8 nm.The pyrolysis behavior of Fe-C/HA was studied by TG-DSC.The results have shown that Fe-C/HA is more stable than humic acid and is not easily pyrolyzed at350℃.The mechanism of removal of CR by Fe-C/HA is accomplished through two stages.The first stage conforms to the second-order kinetic model and Langmuir model,so the adsorption process is carried out by chemical adsorption of monolayer.The adsorption reaction is spontaneous and exothermic at normal temperature.The second stage conforms to the second-order kinetic model.Figure38;Table13;Reference 69.