| This dissertation mainly studied the adsorption capabilities of lead and copper by original carbon nanotubes and carbon nanotubes oxidized by nitric acid, and the factors such as solution inatial pH affecting the adsorption were also discussed. The preparation methods of the freeze-dried xerogels of calcium alginate fibers and beads and the carbon nanotubes-alginate compound material were studied, at the same time, the factors affecting the adsorption were also discussed. In addition, the macro-morphology and microstructure of the adsorbents were observed and characterized.The adsorption results show that the adsorption capabilities of lead and copper by carbon nanotubes oxidized by nitric acid evidently enhanced, and increases the adsorption capabilities several times for Pb2+ and Cu2+ than original carbon nanotubes.The morphology configuration and drying methods of calcium alginate xerogel have important influence on the adsorption capabilities of lead and copper, the results show that the adsorption capabilities of lead by calcium alginate fibrous xerogel is superior to the beads, and the adsorption rate is significantly larger than the beads. The Pb2+ maximum biosorption capacity of calcium alginate fibrous xerogel reaches 417mg/g at temperature of 60℃and pH=5.0. The Cu2+ adsorption capacity of freeze-dried calcium alginate sheet-like xerogel was stronger than those dried in air or at temperature of 50℃, and the Cu2+ maximum biosorption capacity of freeze-dried calcium alginate sheet-like xerogel reached 98.04 mg/g at temperature of 60℃.The carbon nanotubes-alginate compound material could well solve the problem of the second water micro-pollution caused by small size of carbon nanotubes, and the Cu2+ monolayer maximum biosorption capacity of the carbon nanotubes-alginate compound material reaches 80.65 mg/g at room temperature. |
PDF Full Text Request