碱改性生物炭处理含Cd^(2+)废水效果对比研究

Study on Adsorption Mechanism of Cd Wastewater by Modified Biochar

以水稻秸秆(BC_(1))和玉米秸秆(BC_(2))为原料来制备原始生物炭,分别采用碱改性(KOH、NaOH)来对这两种生物炭进行改性,采用FITR对改性前后的生物炭进行表征,并模拟废水中Cd^(2+)的吸附实验。结果表明,碱改性对生物炭的理化性质和表面结构产生了影响,动力学吸附实验表明生物炭对水中Cd^(2+)的吸附过程均符合准二级动力学模型,即其吸附类型均为化学吸附。而等温吸附实验则说明改性生物炭均符合Langmuir模型,其中改性方法的碱性强弱和原料种类也会影响改性生物炭对Cd^(2+)的吸附效果。

The original biochar was prepared from rice straw(BC_(1)) and corn straw(BC_(2)),and alkali modification(KOH,NaOH)was used to modify the two biochars,respectively.The biochar before and after modification was characterized by FITR and the adsorption experiment of Cd^(2+) in wastewater was simulated.The results show that alkali modification has an impact on the physicochemical properties and surface structure of biochar,and the kinetic adsorption experiment shows that the adsorption process of biochar to Cd^(2+) in water is in line with the quasi-secondary kinetic model,that is,its adsorption type is chemical adsorption.The isothermal adsorption experiment shows that the modified biochar is in line with the Langmuir model,in which the alkaline strength of the modified method and the type of raw material will also affect the adsorption effect of modified biochar on Cd^(2+).