Zhao Hua-Xuan, Lang Yin-Hai
College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
Huan Jing Ke Xue. 2018 Aug 8;39(8):3729-3735. doi: 10.13227/j.hjkx.201712138.
A magnetic reed biochar (MBC) was fabricated through chemical coprecipitation first and subsequent pyrolysis of reed stalk powder precipitated with Fe/Fe at 873.15 K. The structure and properties of the MBC were characterized using SEM, BET, FTIR, and VSM. Adsorption experiments were carried out to investigate the adsorption behaviors and mechanisms of ciprofloxacin (CIP) and ofloxacin (OFL) onto the MBC. The MBC possessed roughness and pores within its structure and contained a large amount of oxygen-containing functional groups on the surface. The BET surface area of the MBC was 254.6 m·g, and the total pore volume was 0.257 cm·g, thus the MBC exhibited a relatively high porosity. The adsorption process was found to be pH and temperature dependent. The relative contributions of adsorbate species (cations, zwitterions, and anions) to overall adsorption varied for different pH values. Thermodynamic parameters indicated that the CIP and OFL adsorption onto MBC was a spontaneous, endothermic, and entropy-increasing process. Kinetics and isotherm data of CIP and OFL adsorption onto MBC were well depicted by the pseudo-second-order model and the Langmuir model. The equilibrium adsorption capacities of CIP and OFL onto MBC were 27.84 mg·g and 22.00 mg·g, respectively. Pore-filling effects, π-π interaction between electron donors and acceptors, hydrogen bonding formation, hydrophobic interaction, and electrostatic interaction may be important mechanisms for CIP and OFL adsorption onto the MBC.
首先通过化学共沉淀法制备磁性芦苇生物炭（MBC），随后对用铁/铁沉淀的芦苇秸秆粉末在873.15 K下进行热解。采用扫描电子显微镜（SEM）、比表面积分析仪（BET）、傅里叶变换红外光谱仪（FTIR）和振动样品磁强计（VSM）对MBC的结构和性能进行了表征。进行吸附实验以研究环丙沙星（CIP）和氧氟沙星（OFL）在MBC上的吸附行为及机理。MBC结构内具有粗糙度和孔隙，表面含有大量含氧官能团。MBC的BET比表面积为254.6 m²/g，总孔容为0.257 cm³/g，因此MBC表现出较高的孔隙率。发现吸附过程与pH值和温度有关。对于不同的pH值，吸附质物种（阳离子、两性离子和阴离子）对总吸附的相对贡献各不相同。热力学参数表明，CIP和OFL在MBC上的吸附是一个自发、吸热且熵增加的过程。CIP和OFL在MBC上吸附的动力学和等温线数据用准二级模型和朗缪尔模型得到了很好的描述。CIP和OFL在MBC上的平衡吸附容量分别为27.84 mg/g和22.00 mg/g。孔隙填充效应、电子供体与受体之间的π-π相互作用、氢键形成、疏水相互作用和静电相互作用可能是CIP和OFL在MBC上吸附的重要机制。
