中文关键词
环丙沙星氧氟沙星磁性生物炭离子形态贡献吸附机制 | 英文关键词ciprofloxacin(CIP)ofloxacin(OFL)magnetic biochar(MBC)species contributionsorption mechanism |
|
| 中文摘要 |
| 采用化学共沉淀方法将Fe2+/Fe3+和芦苇生物质材料进行复合，然后于873.15 K限氧热解制备出具有磁分离及高吸附性能的磁性生物炭（MBC）.利用SEM、BET、FTIR和VSM等对其理化性质进行表征，并考察了MBC对水中环丙沙星（CIP）和氧氟沙星（OFL）的吸附行为和机制.结果表明，MBC表面含有大量的含氧官能团，比表面积和总孔体积分别为254.6 m2·g-1和0.257 cm3·g-1.MBC对CIP和OFL的吸附有很强的pH和温度依赖性.不同pH下，CIP和OFL各形态离子（阳离子、两性离子和阴离子）对吸附的贡献不同.MBC对CIP和OFL的吸附过程为自发、熵增的吸热过程.CIP和OFL在磁性炭上的吸附动力学符合准二级动力学模型，吸附等温线符合Langmuir模型.MBC对CIP和OFL的平衡吸附量分别为27.84 mg·g-1和22.00 mg·g-1.孔填充作用、π-π电子供体受体作用、氢键作用、疏水作用和静电作用可能是MBC吸附CIP和OFL的重要机制. |
| 英文摘要 |
| A magnetic reed biochar (MBC) was fabricated through chemical coprecipitation first and subsequent pyrolysis of reed stalk powder precipitated with Fe2+/Fe3+ 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 m2·g-1, and the total pore volume was 0.257 cm3·g-1, 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-1 and 22.00 mg·g-1, 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. |
PDF全文下载地址:
https://www.hjkx.ac.cn/hjkx/ch/reader/create_pdf.aspx?file_no=20180831&flag=1&journal_id=hjkx&year_id=2018