Study Of Preparation And Adsorption-Desorption Performance Of Various Activated Carbon Materials From Reed

Due to plenty of porous structure, the active carbon with strong adsorption capacity can be widely used in water treatment. Recently, considering market economy, the agroforestry by-products based activated carbons were getting popular. Reed as a widely distributed herbaceous plant with high biomass, short growth cycle and strong generativity is widely used in many fields but active carbon area. It is necessary to expand applications of reed active carbon materials. In this paper, yield, specific surface area, pore structure, surface chemical properties and absorption-desorption performance of activated carbons prepared from original reed stocks, reed cellulose and reed cellulose fiber were studied:Firstly, original reed stocks activated carbons(RAC) were prepared from original reed through K2CO3 chemical activation under 650~900℃ with chemical mixture ratio of 0~3.Results show that yields and BET specific surface area of RAC were 61.72~75.34%,84.92~1000.46 m2/g, micropore(mainly 0.37~0.54 nm) volume accounts for 77% of the total pore volume, containing abundant functional groups. The adsorption capacity of MB on RAC was corresponding to BET specific surface area, and revealed the best sample was RAC-850-1 under 850 ℃ with mixing ratio is 1. Under 30 ℃, the equilibrium, kinetics,mechanism of MB on RAC-850-1 in line with the Langmuir isotherm, second-order kinetics,membrane diffusion model, and the maximum monolayer adsorption capacity up to 704.23mg/g. The adsorption thermodynamics data show that the adsorption is spontaneous,endothermic and increasing entropy. During desorption experiment, 85.15% of regeneration ratio was obtained after one regeneration cycle with 95 vol.% ethanol solution.Secondly, reed cellulose was extracted from reed, and further to be made to reed cellulose fiber using NMMO method, then reed cellulose activated carbon(RCAC-850-1) and reed cellulose fiber activated carbon(RCFAC-850-1) were made similar to the preparation condition of RAC-850-1. Results show that the specific surface area of RCAC-850-1 and RCFAC-850-1 are 1112.69 m2/g and 811.18 m2/g, respectively. The corresponding micropore volume accounts for 77.85% and 78.84% of the total pore volume. Their maximum monolayer adsorption capacity are 735.29 mg/g and 632.91 mg/g. During desorption experiment, 84.03% and 83.82% of regeneration ratio of RCAC-850-1 and RCFAC-850-1 are obtained after one regeneration cycle with 95 vol.% ethanol solution. In addition, aspects of pore size distribution, functional groups, adsorption data simulation and thermodynamic results were similar to the RAC-850-1.