CuFeO_(2)改性生物炭对四环素的吸附特性

Adsorption Characteristics of Tetracycline by CuFeO_(2)⁃modified Biochar

利用共沉淀和水热法于生物炭(BC250、 BC350、 BC450、 BC550和BC650)负载CuFeO_(2),得到的复合材料对水中四环素(TC)具有较好的去除效果.CuFeO_(2)与BC450质量比为2∶1的CuFeO_(2)改性生物炭(CuFeO_(2)/BC450=2∶1)对TC的吸附性能最强.TC于CuFeO_(2)/BC450=2∶1的吸附符合颗粒内扩散模型,表明吸附是界面和孔隙扩散控制的过程.在中性pH、 298 K下,CuFeO_(2)/BC450=2∶1对TC的Langmuir最大吸附量为82.8 mg·g^(-1),远大于BC450的13.7 mg·g^(-1)和CuFeO_(2)的14.8 mg·g^(-1).热力学结果表明,CuFeO_(2)/BC450=2∶1对TC的吸附是自发和吸热过程.随pH增加,CuFeO_(2)/BC450=2∶1对TC的吸附去除呈先增加后降低的趋势,中性条件时效果最佳.CuFeO_(2)/BC450=2∶1对TC的强吸附得益于CuFeO_(2)负载对材料孔隙结构的改善、比表面积的增大和表面官能团、电荷属性的改变.研究结果为净化抗生素污染提供了一种高效的磁性吸附剂.

CuFeO_(2)⁃modified biochars were prepared through co⁃precipitation and hydrothermal methods,and the composites had high efficiency removal for tetracycline(TC)from water.The CuFeO_(2)⁃modified biochar with a 2∶1 mass ratio of CuFeO_(2) to BC450(CuFeO_(2)/BC450=2∶1)demonstrated the best adsorption performance.The kinetic process of TC adsorption by CuFeO_(2)/BC450=2∶1 was well fitted with the intraparticle diffusion model,suggesting that the adsorption process was controlled by film and pore diffusion.Under the condition of neutral pH and 298 K,the maximum adsorption capacity of the Langmuir model of CuFeO_(2)/BC450=2∶1 was 82.8 mg·g^(-1),which was much greater than that of BC450(13.7 mg·g^(-1))and CuFeO_(2)(14.8 mg·g^(-1)).The thermodynamic data suggested that TC sorption onto CuFeO_(2)/BC450=2∶1 was a spontaneous and endothermic process.The removal of TC by CuFeO_(2)/BC450=2∶1 increased first and then decreased with increasing pH,and the maximum adsorption occurred under the neutral condition.The strong adsorption of TC by CuFeO_(2)/BC450=2∶1 could be attributed to better porosity,larger specific surface area,and more active sites(e.g.,functional groups and charged surfaces).This work provided an efficient magnetic adsorbent for removing antibiotics.