Preparation Of Monolithic Porous Carbon Materials And Study On High-Efficiency Antibiotic Separation

With the increase of antibiotics in water,the research of antibiotic removal methods has attracted extensive attention all over the world.The most feasible approach to restrict antibiotic emission is to reduce the daily use of antibiotics.In addition,the development and application of new technologies and methods for effective treatment of antibiotics in the environment are extremely important.Porous carbon materials have potential applications in many areas,including catalysis,adsorption,drug delivery,and environmental protection.This project studies the adsorption behavior of carbon materials on antibiotics by taking cefalexin as the model of antibiotics using carbon materials with large specific surface area,rich pore structure and other characteristics,aiming to treat the serious pollution of antibiotics concerned at present.The traditional carbon materials applied for the adsorption of pollutants are in powder state,which is not conducive to the recovery of pollutants after adsorption.Therefore,our goal is to prepare three-dimensional porous carbon monoliths using economical materials.The recycling of pollutants will be of great significance to environmental protection and sustainable human development.The main research contents are as follows:(1)Commercial polyurethane(PU)foam as the template and carbon precursor,ethyl orthosilicate(TEOS)as the"supproting scaffold",and nickel nitrate as the catalyst were used to prepare monolithic carbon materials with interconnected macropores for adsorption of antibiotics.Carbonaceous organic gases pyrolyzed from PU foam were captured by mesoporous silica which coated on the branches of PU foam uniformly then converted into carbon under catalysis of Ni species by high temperature treatment.The geometric shape and interconnected network of PU foam were preserved in TD-HPCM,which had a large specific surface area(1111 m~2/g)and uniform mesoporous size(6.7nm).(2)The carbon monolith was synthesized by self-assembly of resorcinol and HMT under hydrothermal conditions.HMT resolved into formaldehyde and ammonia in the hydrothermal process,which were used as partial carbon precursors and nitrogen source,respectively.Then,the monolithic polymer was formed through self-assembly of formaldehyde and resorcinol under the catalysis of ammonia.After annealing process,the N-PCM was prepared.The N-PCM with tailorable macrostructure possessed high specific surface area(1124 m~2/g),rich porous structure and reasonable N content(2.1%).(3)The adsorption effects of TD-HPCM and N-PCM in the cephalexin solution were studied in detail.The adsorption performance was determined from the adsorption equilibrium curve,adsorption kinetics curve,thermal stability and recycling capacity.All of the monolith carbon materials prepared in this project had excellent adsorption performance.The experimental results showed that the maximum adsorption capacity of TD-HPCM was 288.4 mg/g.Its equilibrium data conformed to the Freundlich model,and the kinetic data were consistent with the pseudo-second-order equation.The maximum adsorption capacity of N-PCM was 305.2 mg/g.Its equilibrium data conformed to the Langmuir model,and the kinetic data were consistent with the pseudo-second-order equation.