Fe/Mg负载改性竹炭去除水中的氨氮

Removal of ammonia nitrogen by Fe/Mg-modified bamboo charcoal

用Mg Cl2溶液、Fe Cl3溶液浸渍对竹炭进行改性,以BET比表面积和SEM-EDS对其进行表征。通过静态吸附实验,研究改性竹炭对氨氮的吸附特性以及吸附时间、初始氨氮浓度、p H值和磷存在等因素对改性竹炭吸附氨氮能力的影响。实验表明,用氯化镁和氯化铁对竹炭进行改性,可使竹炭表面化学性质和物理结构特性同时发生变化;未改性竹炭与改性竹炭对氨氮的吸附量大小依次为:BC<MBC<FBC<FMBC;竹炭在吸附时间为24 h时基本达到吸附平衡,吸附过程符合准二级动力学方程;改性竹炭对氨氮的吸附等温方程与Freundlich模型拟合较好;改性竹炭对氨氮吸附的最佳p H为5;磷存在可使改性竹炭对氨氮的吸附量显著增加。

The bamboo charcoal was modified by dipping in the Mg Cl2 and Fe Cl3 solutions,and characterized by the BET surface area and SEM-EDS. The adsorption characteristics onto the modified bamboo charcoal were studied in batch tests,meanwhile,the effects of various parameters such as absorption time,concentrations,p H and phosphorus solutions on ammonia nitrogen absorption efficiency of modified bamboo charcoal were investigated. The result showed that after modification,the surface chemical properties and physical structure characteristics changed at the same time. The order of the original and modified bamboo charcoal adsorption capacity of ammonia nitrogen was BC MBC FBC FMBC. The bamboo charcoals all reached to adsorption equilibrium after 24 h,and the adsorption processes were fitting to pseudo-second-order kinetic model. The adsorption process of ammonia by modified bamboo charcoal followed Freundlich isothermal equations well. The adsorption optimum p H was 5. When there was phosphorus solution,the adsorption capacity of ammonia increased significantly.