The adsorption behaviors of ammonium ions from aqueous solution by a novel bioadsorbent, the Boston ivy （Parthenocissus tricuspidata） leaf powder （BPTL） were investigated. The SEM images and FT-IR spectra were use...The adsorption behaviors of ammonium ions from aqueous solution by a novel bioadsorbent, the Boston ivy （Parthenocissus tricuspidata） leaf powder （BPTL） were investigated. The SEM images and FT-IR spectra were used to characterize BPTL. The mathematical models were used to analyze the adsorption kinetics and isotherms. The optimum pH range for ammonium adsorption by BPTL was found to be 5-10. The adsorption reached equilibrium at 14 b.r, and the kinetic data were well fitted by the Logistic model. The intraparticle diffusion was the main rate-controlling step of the adsorption process. The high temperature was favorable to the ammonium adsorption by BPTL, indicating that the adsorption was endothermic. The adsorption equilibrium fitted well to both the Langmuir model and Freundlich model, and the maximum monolayer adsorption capacities calculated from Langmuir model were 3.37, 5.28 and 6.59 mg N/g at 15, 25 and 35~C, respectively, which were comparable to those by reported minerals. Both the separation factor （RL） from the Langmuir model and Freundiich exponent （n） suggested that the ammonium adsorption by BPTL was favorable. Therefore, the Boston ivy leaf powder could be considered a novel bioadsorbent for ammonium removal from aqueous solution.展开更多
A novel nanocomposite bioadsorbent rectorite/chitosan was prepared by controlling different mass ratios of chitosan to rectorite using the water phase intercalation technique. The structure of the bioadsorbent was cha...A novel nanocomposite bioadsorbent rectorite/chitosan was prepared by controlling different mass ratios of chitosan to rectorite using the water phase intercalation technique. The structure of the bioadsorbent was characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM), Transmission electron microscopy (TEM), respectively. The results showed that the chitosan had been inserted into the rectorite layer successfully. The adsorption properties of the nanocomposite adsorbent toward CHCl3 from aqueous solution were investigated. Adsorption results showed that both nanocomposite adsorbents with weight ratio of rectorite to chitosan of 3:1 and 5:1 exhibited higher adsorption capacities.展开更多
NaOH-modified dead leaves of plane trees were used as bioadsorbent to remove methylene blue (MB) from aqueous solution. Variable influencing factors, including contact time, temperature, initial MB concentration and p...NaOH-modified dead leaves of plane trees were used as bioadsorbent to remove methylene blue (MB) from aqueous solution. Variable influencing factors, including contact time, temperature, initial MB concentration and pH were studied through single-factor experiments. The results showed that the initial concentration 100 mg/L, bioadsorbent of 2.5 g/L, pH of 7, room temperature were the best adsorption conditions. The NaOH-modified bioadsorbent had a high adsorption capacity for MB, and its saturated extent of adsorption was 203.28 mg/g, which was higher than the un-modified dead leaves (145.62 mg/g) and some other bioadsorbents. Finally, adsorption kinetics and isotherms were discussed, suggesting that the Langmuir isotherm model and Pseudo-second order kinetics were fitted well with the adsorption process.展开更多
The surface of a biowaste was modified by introduction of amino group for the purification of wastewater contaminated with heavy metals. In this study waste tea leaf was used as a biowaste which was an economic and ef...The surface of a biowaste was modified by introduction of amino group for the purification of wastewater contaminated with heavy metals. In this study waste tea leaf was used as a biowaste which was an economic and efficient bioadsorbent. The aminated tea leaves were characterized by spectral and elemental analysis. The adsorption capacity of the surface modified biosorbent was studied as the function of solution pH, concentration of metal ions and contact time of adsorption. The applicability of Langmuir isotherm was tested. The adsorption capacities were found to be 83.04 mg/g and 57 mg/g for Pb (II) and Cd (II), respectively. The biosorbent was regenerated by desorption of the metal loaded adsorbent with 0.1 M HNO3. These results showed that the aminated tea leaves may be an attractive alternative for treatment of wastewater contaminated with heavy metals.展开更多
基金supported by the National Supporting Plan of Science and Technology(No.2006BAD10B05)the National Natural Science Foundation of China(No. 20907058)the Natural Science Foundation of Jiangsu Province of China(No.BK2008499)
文摘The adsorption behaviors of ammonium ions from aqueous solution by a novel bioadsorbent, the Boston ivy （Parthenocissus tricuspidata） leaf powder （BPTL） were investigated. The SEM images and FT-IR spectra were used to characterize BPTL. The mathematical models were used to analyze the adsorption kinetics and isotherms. The optimum pH range for ammonium adsorption by BPTL was found to be 5-10. The adsorption reached equilibrium at 14 b.r, and the kinetic data were well fitted by the Logistic model. The intraparticle diffusion was the main rate-controlling step of the adsorption process. The high temperature was favorable to the ammonium adsorption by BPTL, indicating that the adsorption was endothermic. The adsorption equilibrium fitted well to both the Langmuir model and Freundlich model, and the maximum monolayer adsorption capacities calculated from Langmuir model were 3.37, 5.28 and 6.59 mg N/g at 15, 25 and 35~C, respectively, which were comparable to those by reported minerals. Both the separation factor （RL） from the Langmuir model and Freundiich exponent （n） suggested that the ammonium adsorption by BPTL was favorable. Therefore, the Boston ivy leaf powder could be considered a novel bioadsorbent for ammonium removal from aqueous solution.
文摘A novel nanocomposite bioadsorbent rectorite/chitosan was prepared by controlling different mass ratios of chitosan to rectorite using the water phase intercalation technique. The structure of the bioadsorbent was characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM), Transmission electron microscopy (TEM), respectively. The results showed that the chitosan had been inserted into the rectorite layer successfully. The adsorption properties of the nanocomposite adsorbent toward CHCl3 from aqueous solution were investigated. Adsorption results showed that both nanocomposite adsorbents with weight ratio of rectorite to chitosan of 3:1 and 5:1 exhibited higher adsorption capacities.
文摘NaOH-modified dead leaves of plane trees were used as bioadsorbent to remove methylene blue (MB) from aqueous solution. Variable influencing factors, including contact time, temperature, initial MB concentration and pH were studied through single-factor experiments. The results showed that the initial concentration 100 mg/L, bioadsorbent of 2.5 g/L, pH of 7, room temperature were the best adsorption conditions. The NaOH-modified bioadsorbent had a high adsorption capacity for MB, and its saturated extent of adsorption was 203.28 mg/g, which was higher than the un-modified dead leaves (145.62 mg/g) and some other bioadsorbents. Finally, adsorption kinetics and isotherms were discussed, suggesting that the Langmuir isotherm model and Pseudo-second order kinetics were fitted well with the adsorption process.
文摘The surface of a biowaste was modified by introduction of amino group for the purification of wastewater contaminated with heavy metals. In this study waste tea leaf was used as a biowaste which was an economic and efficient bioadsorbent. The aminated tea leaves were characterized by spectral and elemental analysis. The adsorption capacity of the surface modified biosorbent was studied as the function of solution pH, concentration of metal ions and contact time of adsorption. The applicability of Langmuir isotherm was tested. The adsorption capacities were found to be 83.04 mg/g and 57 mg/g for Pb (II) and Cd (II), respectively. The biosorbent was regenerated by desorption of the metal loaded adsorbent with 0.1 M HNO3. These results showed that the aminated tea leaves may be an attractive alternative for treatment of wastewater contaminated with heavy metals.
