Lignin was extracted from ecological invasive plant water hyacinth by alkali extraction.The extracted product was characterized by FT-IR and SEM methods.The effects of some factors such as pH value,adsorption time,initial concentration on the adsorption capacity of water hyacinth lignin for aniline were evaluated.When the concentration of NaOH solution was 0.1 mol/L,the extraction time was 4 h,temperature was 100 ℃,and the solid-liquid ratio was 1∶20,the yield of water hyacinth lignin was the maximum of 6.81%.The infrared spectrum showed the stretching vibrations of the C‖C bonds in the aromatic skeleton at 1 456-1 656 cm-1.The results of the infrared spectrum indicated that the obtained product was lignin.The result of SEM showed that water hyacinth lignin composed of a large number of small amorphous particles,and there were many micro pores on the surface of lignin particles,which would be benefit to increase the adsorption capacity.The maximum adsorption capacity reached up to 12.2 mg/g at pH 6.0 with an initial concentration of aniline of 150 mg/L,an adsorbent dosage of 5 mg and an adsorption time of 120 min at room temperature.The adsorption data fited well with the Pseudo second order kinetics model and the Langmuir isotherm model.The adsorption of aniline by water hyacinth lignin was mainly assigned to chemical adsorption of monolayer and favorable adsorption.Under the same adsorption conditions,the adsorption capacities of water hyacinth lignin for aniline in a lake water samples were similar to that in the simulated water samples.Water hyacinth lignin could be used as enrichment and seperation material for sample pretreatment and removing pollutant in wastewater. |