Adsorption Of U(Ⅵ) In Aqueous Solution By Organic Char

Bone, pine needles and chitosan (CTS)are organic materials common in daily life,has the advantages of cheap, wide distribution range, environmentally friendly, used forpreparing carbon materials can greatly reduce the preparation cost. The organic char is akind of environmental friendly adsorbent for adsorption of heavy metal ions, Will notcause pollution two. The organic char was prepared by pyrolysis method, hydrothermalmethod, it was characterization by scanning electron microscopy (SEM), X ray diffraction(XRD), infrared spectroscopy (FT-IR), N2adsorption desorption. And then studied theorganic char adsorption of uranium, including uranium solution pH, adsorption time, initialconcentration of uranium solution, adsorption temperature, and dynamics, adsorptionisotherm and thermodynamic studies on the adsorption, used to determine the adsorptionmechanism.The pyrolysis method was used to tread bone，In the existing of protective gas boneorganic char was prepared, bone ash was prepared without protective gas. Show that bone,bone char and bone ash contains a large number of hydroxyapatite, bone is a kind ofmesoporous materials. The adsorption of uranium (VI) behavior on bone char conforms topseudo-second-order kinetic model and Langmuir isotherm model, which indicate that theadsorption is mainly affected by the monolayer adsorption process of chemical control, it isa process of endothermic and spontaneous. The adsorption of uranium on bone char andbone ash is better than bone, but the adsorption mode does not change.Using pine needles as material, citric acid as activator, hydrothermal carbon(HTC)was prepared by hydrothermal method, through nitrate acid for carboxylation treatment onhydrothermal carbon（HTC）, carboxylated hydrothermal carbon（HTC-COOH） wasprepared. The characterization results show that hydrothermal carbon contain a largenumber of carboxyl groups after the treatment of nitrate acid., and pore size did not change much. The adsorption of uranium (VI) behavior on HTC and HTC-COOH conforms topseudo-second-order kinetic model and Langmuir isotherm model, which indicate that theadsorption is mainly affected by the monolayer adsorption process of chemical control, it isa process of endothermic and spontaneous. The ability of the carboxylation process afterhydrothermal carbon adsorption of uranium has been improved, no change in adsorptionmethod.As the adsorbent was prepared by using chitosan materials, the preparation ofchitosan hydrothermal carbon (CHC) by one step hydrothermal method, which does notadd any toxic crosslinking agent, The different hydrothermal carbon were prepared acrossdifferent hydrothermal temperature (170℃-210℃) and hydrothermal time (3h-48h). Thestudy found with increasing hydrothermal temperature and hydrothermal time,hydrothermal carbon stability in acidic solution is higher, but for uranium (VI) adsorptionvolume declined. The adsorption of uranium (VI) behavior on CTS and CHC conforms topseudo-second-order kinetic model and Langmuir isotherm model, which indicate that theadsorption is mainly affected by the monolayer adsorption process of chemical control, it isa process of endothermic and spontaneous.