Cui Qiushuang, Huang Yong, Ma Xufei, Li Sining, Bai Ruyun, Li Huan, Liu Wen, Wei Hanyu
State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources, College of Chemistry, Xinjiang University, Urumqi 830017, China.
College of Civil Engineering and Architecture, Xinjiang University, Urumqi 830017, China.
Molecules. 2024 Dec 11;29(24):5841. doi: 10.3390/molecules29245841.
In this research, we produced two types of biochar (BC) using cotton stalks as raw material and KOH as an activator, and compared their performance and adsorption mechanisms in the removal of tetracycline (TC) and methylene blue (MB) from wastewater. The results showed that the biochar generated using both procedures formed pores that connected to the interior of the biochar and had extensive microporous and mesoporous structures. The molten salt approach produces biochar with a higher specific surface area, larger pore size, and higher pore volume than the impregnation method, with a maximum specific surface area of 3095 m/g. KBCM-900 (the BC produced using the molten salt method at 900 °C) had a better adsorption effect on TC, with a clearance rate of more than 95% in 180 min and a maximum adsorption amount of 912.212 mg/g. The adsorption rates of the two BCs for MB did not differ significantly at low concentrations, but as the concentration increased, KBCI-900 (the BC generated by the impregnation method at 900 °C) exhibited better adsorption, with a maximum adsorption of 723.726 mg/g. The pseudo-second-order kinetic model and the Langmuir isotherm model may accurately describe the TC and MB adsorption processes of KBCI-900 and KBCM-900. The KBCI/KBCM-900 adsorption process combines physical and chemical adsorption, with the primary mechanisms being pore filling, π-π interactions, hydrogen bonding, and electrostatic interactions. As a result, biochar generated using the molten salt method is suitable for the removal of large-molecule pollutants such as TC, whereas biochar prepared using the impregnation method is suitable for the removal of small-molecule dyes such as MB.
在本研究中，我们以棉秆为原料、氢氧化钾为活化剂制备了两种生物炭（BC），并比较了它们在去除废水中四环素（TC）和亚甲基蓝（MB）方面的性能及吸附机制。结果表明，两种制备方法所产生的生物炭均形成了与生物炭内部相连的孔隙，且具有广泛的微孔和中孔结构。与浸渍法相比，熔盐法制备的生物炭具有更高的比表面积、更大的孔径和更高的孔容，最大比表面积为3095 m/g。KBCM - 900（900℃下采用熔盐法制备的生物炭）对TC具有更好的吸附效果，180分钟内去除率超过95%，最大吸附量为912.212 mg/g。两种生物炭对低浓度MB的吸附率差异不显著，但随着浓度增加，KBCI - 900（900℃下采用浸渍法制备的生物炭）表现出更好的吸附性能，最大吸附量为723.726 mg/g。准二级动力学模型和朗缪尔等温线模型可以准确描述KBCI - 900和KBCM - 900对TC和MB的吸附过程。KBCI/KBCM - 900的吸附过程兼具物理和化学吸附，主要机制为孔隙填充、π-π相互作用、氢键和静电相互作用。因此，熔盐法制备的生物炭适用于去除TC等大分子污染物，而浸渍法制备的生物炭适用于去除MB等小分子染料。
