| Activated alumina is a kind of porous solid material.It has a large volume of solid material which is higher than the surface and is a solid material with high adsorption properties.Fly ash is the main solid waste discharged from coal-fired power plants.The main oxides of fly ash are SiO2,Al2O3,FeO,Fe2O3 and so on.The preparation of activated alumina from fly ash can not only make use of waste,but also produce high added adsorption products,which is of great significance to environmental protection and industrial development.This paper uses fly ash as aluminum source(Al),activated alumina by acid and alkali combination method,modified with surfactant,modified by the self-assembly through interaction between organic and inorganic compounds,phase composition,modified product morphology,porosity,pore size,specific surface area X-ray phase analysis,scanning electron microscopy,morphology,BETspecific surface determination and characterization;comparison of before and after modification of activated alumina adsorption properties of copper ion of heavy metal ions in wastewater,the adsorption mechanism was discussed.In this paper,pure activated alumina was prepared by mixing fly ash with soda ash,medium temperature sintering,immersion sulfuric acid,filtration and calcination.The results showed that the optimum conditions for the initial mass ratio of soda ash and fly ash,0.90:1,sintering time was 4 hours(h),the calcination temperature is 400?,calcining aluminum hydroxide for 5 hours(h),the product of the specific surface area of 357.057m2/g,Kong Rong 0.35 cm3/g,the average diameter is 4.317 nm.The modified alumina was modified with three different modifiers(sixteen alkyl three methyl bromide(CTAB),polyethylene imine(PEI)and sodium carboxylate)under optimized process conditions.The three kinds of modifier modified products of both pure activated alumina,the surface area,Kong Rong and average pore diameter were 369.701 m2/g,0.37 cm3/g,4.265nm(CTAB);371.942 m2/g,0.36 cm3/g,4.197nm(PEI);365.721 m2/g,0.40 cm3/g,4.287nm(carboxylic acid sodium).The results showed that the specific surface area,Kong Rong and average pore size of the products were improved to some extent by the three modifiers,and the specific surface area of the modified alumina modified by PEI was the most obvious.Through the adsorption test of copper ion modified activated alumina adsorption of heavy metal solution before and after the control of the adsorption time,initial concentration of wastewater simulated solution,pH value and other conditions on the adsorption properties were characterized.The results show that the adsorption of modified activated alumina before the optimal pH value and adsorption rate were 5 and 68.79%.The use of different modifiers to optimize the adsorption of activated alumina after pH and adsorption rate was modified by CTAB was 5 and 75.43%,the modified PEI was 3 and 77.02%,carboxylic acid modified by sodium were 3 and 76.22%,by three kinds of modifiers,different extent increased adsorption the product of copper ion of heavy ion in wastewater rate.Among them,PEI modified the best effect,in its best pH conditions,the adsorption rate of copper ions in heavy metal wastewater reached 77.02%. |
PDF Full Text Request