以不锈钢企业盐酸酸洗废水为活化剂,柚子皮为原料,采用简单一步法制备铁基磁性活性炭,考察不同条件下该碳材料的氨氮吸附性能。扫描电镜和N₂-吸脱附表征结果显示:700℃焙烧所得活性炭具有较大的比表面积(758.6m²/g)和良好的氨氮吸附性能,并具有一定磁性易通过磁性辅助技术分离。采用准一级动力学方程、准二级动力学方程和颗粒内扩散方程对磁性活性炭吸附氨氮进行拟合,吸附动力学较符合准二级动力学方程。吸附等温方程符合Freundlich等温模式,氨氮在磁性活性炭表面的吸附为吸热过程,以物理吸附为主,同时伴随NH⁺₄与磁性活性炭表面Fe³⁺之间的离子交换。

A series of iron based magnetic activated carbon (MAC) were prepared from pomelo peel via a simple one-step method using hydrochloric acid pickling water as chemical activation agent and iron oxide precursor.The adsorption performance of ammonia-nitrogen on MAC (973) was investigated at different conditions.The surface property and pore structure were characterized by SEM and BET.The results showed that MAC had a higher specific surface area of 758.6m²/g and can be easily separated from solution using magnetic assisted separation technology (MAST).The adsorption can be well described by fruendlich isothermal model.In addition,the kinetics and thermodynamics results indicated that ammonia-nitrogen-MAC (973) batch adsorption system was well agreed with the pseudo-second-order kinetic model.The process of ammonia-nitrogen adsorption on MAC was an endothermic process,which was mainly based on physical adsorption,and the ion exchange between Fe³⁺ and NH⁺₄ on the surface of magnetic activated carbon.