• 关键词：荞麦皮生物炭  奥硝唑  拉曼光谱  吸附动力学

• 基金项目：国家自然科学基金资助项目（No.51979223）；陕西省自然科学基金资助项目（No.2022JM-093，2021JM-329）

• 魏红
• 西安理工大学， 西北旱区生态水利国家重点实验室，西安 710048

• 史刘敏
• 西安理工大学， 西北旱区生态水利国家重点实验室，西安 710048

• 钮金芬
• 西安理工大学应用化学系，西安 710048

• 董雯
• 西安理工大学， 西北旱区生态水利国家重点实验室，西安 710048

• 付冉
• 西安理工大学， 西北旱区生态水利国家重点实验室，西安 710048

• 摘要：以农林废弃物荞麦皮为原料制备生物炭（BBC），采用XRD、Raman、N₂吸附/脱附、FTIR和XPS方法对BBC进行表征，研究其对奥硝唑（Ornidazole，ONZ）的吸附性能及机理.结果表明，热解温度在400~800 ℃， BBC的得炭率为24.5%~34%；温度升高，BBC的芳香性和稳定性增加（H/C由0.047降低至0.013），比表面积和孔容升高，对ONZ的吸附率增加.采用不同动力学和吸附等温线模型对不同热解温度BBC吸附ONZ的过程进行模拟，吸附过程符合准二级动力学模型和Langmuir吸附等温线模型，表明BBC对ONZ的吸附为单层吸附.其中热解温度为800 ℃时的BBC（BBC-800）对ONZ的吸附效果最好，最大吸附量达到27.12 mg?g^-1.初始pH为3.02~11.03，对BBC-800吸附ONZ的影响不大；共存离子（Na⁺、NH₄⁺、CO₃^2-、HCO₃^-和SO₄^2-）对吸附过程有一定促进作用； 腐殖酸（HA）抑制吸附效果， 5.0 g?L^-1时ONZ的吸附率由97.15%下降至56.86%. FTIR、N₂吸附/脱附和XPS分析结果表明， BBC-800对ONZ的吸附机制主要包括孔隙扩散，生物炭表面与ONZ分子间的氢键、π-π和p-π共轭作用. BBC-800能够有效去除实际水体（污水厂二沉池出水、湖水）中ONZ的残留. 吸附-解吸3次循环实验表明，BBC-800仍具有较好的吸附性能， 对ONZ的吸附容量为14.10 mg?g^-1. 研究结果对荞麦皮的资源化及奥硝唑类药物的有效去除具有重要参考价值.

• Abstract：Buckwheat husk Biochar （BBC） was prepared and characterized by XRD， Raman， N₂ adsorption/desorption， FTIR and XPS analysis methods. Its adsorption performance and mechanism for Ornidazole （ONZ） were investigated in detail. The results showed that BBC carbon yield achieved 24.5%~34.0% when the pyrolysis temperature was in range of 400~800 ℃. The aromaticity， stability （H/C decreased from 0.047 to 0.013）， specific surface area and pore volume of BBC increased with pyrolysis temperature， and the faster and higher adsorption effect was exhibited for ONZ. In addition， the pseudo-second-order kinetic model can well describe the adsorption process， indicating it a more complicated interaction. Langmuir model well fitted the adsorption isotherm， showing that BBC mainly removes ONZ by monolayer adsorption. BBC-800 exhibited the best adsorption removal for ONZ， with the maximum adsorption capacity of 27.12 mg?g^-1 calculated by Langmuir model. The pH value had little effect on ONZ adsorption in range of 3.02~11.03. Coexisting ions such as Na⁺、NH₄⁺、CO₃^2-、HCO₃^- and SO₄^2- improved ONZ adsorption a little. Humic Acid inhibited the process with ONZ adsorption rate decreasing from 97.15% to 56.86%. Together with the FTIR， N₂ adsorption/desorption and XPS analysis， it was speculated that the adsorption mechanism should be attributed to the pore-filling effect， hydrogen bonding， π-π and p-π conjugation between BBC surface and ONZ molecule. The excellent performance of BBC-800 made it remove ONZ residual effectively from the sedimentation tank and lake water. BBC-800 still had good regeneration performance， with the adsorption capacity remaining 14.10 mg?g^-1 after three adsorption -desorption cycle. The results are of great significance for the utilization of buckwheat husk and the removal of ONZ residual from water.

• Key words：buckwheat husk biochar  ornidazole  raman spectrum  adsorption dynamics

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