改性废弃茶叶生物炭的制备及对印染废水中结晶紫的吸附OA

In order to effectively solve the printing and dyeing wastewater produced by the textile industry,under the guidance idea of"treating the wastes with wastes",biochar derived from tea waste was prepared via KOH-assisted pyrolysis modification,and achieved efficient adsorption of crystal violet from printing and dyeing wastewater.The biochar samples were characterized by SEM,BET and FTIR.The effects of activation temperature,biochar dosage,initial concentration and solution pH value on the pore structure of biochar and the removal of crystal violet from printing and dyeing wastewater were investigated.The adsorption test showed that the removal efficiency of 20 mg/L crystal violet by 10 mg KOH-modified waste tea biochar could be reached 99.8％within 45 min at pH=9.Compared with unmodified waste tea biochar,the adsorption capacity was increased from 27.98 mg/g to 49.60 mg/g.After five cycle tests,the removal efficiency of crystal violet was remained above 80％.The adsorption process was well fitted with the quasi-primary kinetic model and the Langmuir isotherm model.Theoretical calculations showed that the adsorption capacity of modified waste tea biochar for crystal violet was-218.46 kJ/mol,which was much larger than that of unmodified waste tea biochar(-95.02 kJ/mol),which together with infrared spectroscopy results proved that the modified waste tea biochar could achieve more efficient adsorption by increasing the interaction of surface active groups(—OH)with crystal violet.It is considered that the modified waste tea biochar was successfully prepared from tea waste as a carbon source and realized the purification of printing and dyeing wastewater through efficient adsorption,which provides a valuable solution for the development of environmentally friendly printing and dyeing process and reuse of tea production waste.