磁性板栗壳生物炭的制备及其对盐酸四环素的吸附效果研究

Preparation of Magnetic Chestnut Shell Biochar and Its AdsorptionEffect on Tetracycline Hydrochloride

以农业废弃物板栗壳为原料,采用浸渍加热法制得磁性生物炭。表征分析结果表明:载铁改性后的生物炭因负载Fe_(3)O_(4)颗粒而具备磁性,磁性可达39.1 emu/g。等温吸附实验结果表明,未经载铁改性处理的生物炭表面光滑,吸附位点分布均匀,对盐酸四环素的吸附过程更符合Langmuir模型;经过载铁处理后生物炭表面分布Fe_(3)O_(4)颗粒,变得疏松多孔,吸附位点分布不均,对盐酸四环素的吸附过程更符合Freundlich模型。经过载铁改性处理的生物炭对盐酸四环素的吸附容量大幅提升,Fe-AC_(800)的最大理论吸附量可达96.154 mg/g。Fe-AC_(800)吸附盐酸四环素的过程主要受控于物理吸附,为吸热熵增反应,提高温度可增强吸附作用。pH对Fe-AC_(800)吸附四环素的影响较小,这说明Fe-AC_(800)在较宽的pH范围内均对四环素有着很好的吸附效果。

Using chestnut shells as raw materials,magnetic biochar was prepared by immersion heating method.The results of characterization analysis showed that the iron-loaded modified biochar had magnetism due to the loading of Fe_(3)O_(4)particles,which could reach 39.1 emu/g.The results of isothermal adsorption experiments showed that the surface of the biochar without iron-loaded modification was smooth,and the adsorption sites were evenly distributed.The adsorption process of tetracycline hydrochloride was more in line with the Langmuir model.After the iron-loaded treatment,Fe_(3)O_(4)particles were distributed on the surface of the biochar.It was loose and porous with uneven distribution of adsorption sites.The adsorption process of tetracycline hydrochloride was more in line with the Freundlich model.The adsorption capacity of the iron-loaded modified biochar for tetracycline hydrochloride was greatly increased,and the maximum theoretical adsorption capacity of Fe-AC_(800)could reach 96.154 mg/g.The process of Fe-AC_(800)adsorption of tetracycline hydrochloride was mainly controlled by physical adsorption,which was an endothermic entropy increasing reaction.Increasing the temperature can enhance the adsorption.pH had little effect on Fe-AC_(800)’s adsorption of tetracycline,which showed that Fe-AC_(800)had a good adsorption effect on tetracycline in a wide pH range.