Wang Jing, Zhu Xiao-Li, Han Zi-Yu, Hu Jian, Qin Zhi-Rui, Jiao Wen-Tao
College of Urban and Environmental Science, Northwest University, Xi'an 710127, China.
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Huan Jing Ke Xue. 2020 Mar 8;41(3):1319-1328. doi: 10.13227/j.hjkx.201908210.
Three typical porous solid wastes, including livestock manure, crop straw, and coal mining waste, were used as raw materials to prepare cattle manure charcoal, straw charcoal, and coal gangue charcoal by low-oxygen controlling temperature carbonization and calcination. Batch adsorption experiments of sulfamethazine (SMZ) in water were carried out. Adsorption kinetics and isothermal adsorption equilibrium were used to investigate the adsorption characteristics of SMZ on cattle dung charcoal, straw charcoal, and coal gangue charcoal, and the adsorption mechanism was discussed by means of field-electron scanning electron microscope, Fourier transform infrared spectroscopy, Boehm titration, Brunauer-Emmett-Teller measurement, and zeta potentiometric titration. The results showed that the adsorption of SMZ on the three carbon materials reached equilibrium at 24 h. The adsorption kinetics of SMZ on three kinds of carbon materials agreed with the quasi-second-order kinetics equation. ranged from 0.9968 to 0.9999, and the adsorption rate decreased with the decrease in effective adsorption sites on the surface of carbon materials. The adsorption process mainly consists of three steps:membrane diffusion, intraparticle diffusion, and the equilibrium stage. Both intraparticle diffusion and membrane diffusion control the adsorption rate. Isothermal adsorption is more consistent with the Freundlich model. is between 0.9874 and 0.9997. It is mainly physical adsorption and spontaneous exothermic reaction. The maximum adsorption capacity of the three kinds of carbon materials was cattle dung carbon (19.64 mg·g) > coal gangue carbon (12.06 mg·g) > straw carbon (9.16 mg·g). The adsorption mechanism of SMZ on the three kinds of carbon materials mainly includes hydrogen bonding between molecules, surface electrostatic adsorption of multi-molecular layers, and pore filling. Of these, electrostatic adsorption is the main adsorption mechanism. The best adsorption performance of cattle manure charcoal may be due to its rich oxygen-containing functional groups, more negative charges, and larger specific surface area and pore volume.
以三种典型的多孔固体废弃物，即畜禽粪便、农作物秸秆和煤矿废弃物为原料，通过低氧控温碳化和煅烧制备牛粪炭、秸秆炭和煤矸石炭。开展了水中磺胺二甲嘧啶（SMZ）的批量吸附实验。采用吸附动力学和等温吸附平衡研究了SMZ在牛粪炭、秸秆炭和煤矸石炭上的吸附特性，并通过场发射扫描电子显微镜、傅里叶变换红外光谱、 Boehm滴定、 Brunauer-Emmett-Teller测量和zeta电位滴定等手段探讨了吸附机理。结果表明，SMZ在三种炭材料上的吸附在24 h达到平衡。SMZ在三种炭材料上的吸附动力学符合准二级动力学方程，相关系数在0.9968至0.9999之间，且吸附速率随炭材料表面有效吸附位点的减少而降低。吸附过程主要包括三个步骤：膜扩散、颗粒内扩散和平衡阶段。颗粒内扩散和膜扩散均控制吸附速率。等温吸附更符合Freundlich模型，相关系数在0.9874至0.9997之间。主要为物理吸附和自发放热反应。三种炭材料的最大吸附量为牛粪炭（19.64 mg·g）＞煤矸石炭（12.06 mg·g）＞秸秆炭（9.16 mg·g）。SMZ在三种炭材料上的吸附机理主要包括分子间氢键、多分子层表面静电吸附和孔隙填充。其中，静电吸附是主要的吸附机理。牛粪炭最佳的吸附性能可能归因于其富含的含氧官能团、更多的负电荷以及更大的比表面积和孔容。
