Zeng Shao-Yi, Li Kun-Quan
College of Engineering, Nanjing Agricultural University, Nanjing 210031, China.
Huan Jing Ke Xue. 2023 Mar 8;44(3):1519-1527. doi: 10.13227/j.hjkx.202203013.
Using cotton stalk as biomass raw material and phosphoric acid as a modifier, narrow pore distribution phosphorus-containing cotton stalk biochar (CSP) with a high surface area (1916 m·g) and pore volume (1.3982 mL·g) was prepared through one-step carbonization, and the adsorption characteristics and mechanisms for tetracycline (TC) were investigated. The results showed that the TC adsorption capacity of CSP was up to 669 mg·g, which was 43.6 times that of unmodified cotton stalk carbon. FTIR, XPS, and isothermal adsorption studies showed that the high adsorption capacity of CSP for TC resulted from the joint action of complexation, hydrogen bonding, pore filling, and π-π dispersion forces, and the highly active phosphate ester group (P-O-C) endowed by phosphoric acid modification greatly enhanced the chemical interaction with TC molecules, which was the key factor for the significant increase in adsorption capacity. Isotherm and thermodynamic study further confirmed that chemical adsorption played a major role in the adsorption process, the adsorption process was spontaneous and endothermic, and the material had good regeneration performance. This study provides theoretical guidance for the preparation of modified biomass carbon with high adsorption performance to remove tetracycline antibiotic pollution.
以棉秆为生物质原料，磷酸为改性剂，通过一步碳化制备了具有窄孔分布、高比表面积（1916 m²·g）和孔容（1.3982 mL·g）的含磷棉秆生物炭（CSP），并研究了其对四环素（TC）的吸附特性及机制。结果表明，CSP对TC的吸附量高达669 mg·g，是未改性棉秆炭的43.6倍。傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）和等温吸附研究表明，CSP对TC的高吸附能力源于络合、氢键、孔填充和π-π色散力的共同作用，磷酸改性赋予的高活性磷酸酯基团（P-O-C）极大地增强了与TC分子的化学相互作用，这是吸附量显著增加的关键因素。等温线和热力学研究进一步证实，化学吸附在吸附过程中起主要作用，吸附过程是自发的且吸热的，该材料具有良好的再生性能。本研究为制备具有高吸附性能的改性生物质炭去除四环素抗生素污染提供了理论指导。
