功能化磁性多孔生物碳对畜禽养殖生化尾水中四环素-铜络合物的去除作用及机制

Livestock and poultry breeding biochemical tail water still contain higher concentration of tetracycline and copper ions. Their complex compound would seriously influence the quality of water bodies and threat the health of ecological environment. The investigation of efficient removal technology to tetracycline-copper complex compound is urgent. Biochar had been used to remove antibiotic and heavy metal ions in aqueous solution in previous studies. However, the removal process and mechanisms of tetracycline-copper complex compound by biochar are still unknown. In the project, biochar was modified based on the “activation- magnetization- functionalization ” pathway. Then, the modified biochar was characterized by multiple equipments. Static batch and dynamic adsorption column experiment was carried out to study the adsorption behavior and removal efficiency of tetracycline-copper complex compound. Varying aquatic environment factors was conducted to explore the influence of removal effect to tetracycline-copper complex compound. Different models were employed to fit the adsorption process to acquire the performance parameters. The physicochemical properties of liquid phase and surface structure characteristic of solid phase before and after adsorption process were analyzed by advanced spectroscopic technique to reveal the potential mechanisms. Lastly, the modified biochar was applied to treat the real livestock and poultry breeding biochemical tail water to assess the function of adsorbent. The findings of this project could provide a theoretical basis and technological support for the deep treatment of the real livestock and poultry breeding biochemical tail water.

畜禽养殖废水经生化处理后，其尾水中仍含有较高浓度的四环素类抗生素和重金属铜离子，其络合物严重影响到受纳环境水体质量和生态环境健康，对畜禽养殖生化尾水中四环素-铜络合物高效去除技术研究十分必要。前期研究发现生物碳能有效去除水体中的抗生素与重金属离子，但对抗生素-重金属络合物的去除过程和机理尚不明确。本项目拟基于“活化-磁化-功能化”途径制备功能化磁性多孔生物碳，并表征其组成和结构特性，采用静态批次和动态吸附柱实验研究对四环素-铜络合物的吸附行为和去除效能，考察水环境因子对络合物去除的影响，通过模型拟合获取吸附特性参数，运用先进谱镜技术分析吸附平衡前后液相中污染物浓度及生物碳固相表面结构性质的变化，揭示功能性生物碳对四环素-铜络合物的去除机制。最后，开展生物碳对实际畜禽养殖生化尾水中络合物去除的验证试验，评价改性生物碳的实际应用效果。项目研究可为畜禽养殖生化尾水深度处理提供科学依据和技术支撑。

本项目针对畜禽养殖生化废水中四环素-铜离子络合物复合污染控制的问题，通过制备磁性多孔生物炭作为吸附剂来去除废水中的四环素和重金属离子。.本课题以茶渣、秸秆、花生壳、污泥等为原料，通过炭化方法（水热、不同炭化温度、一次炭化、二次炭化等）和改性剂（壳聚糖、FeCl3∙6H2O、KHCO3、KOH、KMnO4、尿素等）的调控，成功制备了多种功能性的改性生物炭，并对生物炭进行了SEM、BET、XRD、FTIR、XPS、Raman、pHPZC、VSM等全面的理化性质表征。研究了生物炭对废水中四环素和重金属离子的吸附动力学和等温线过程，考察了溶液pH和共存离子对吸附行为的影响。特别是研究了溶液中铜离子的存在对生物炭吸附四环素的影响，因为四环素能和铜离子形成络合物，进一步验证生物炭对四环素-铜离子络合物的去除效果及机理。采用吸附后生物炭的BET、FTIR、XPS、Raman表征、矿物质洗涤实验、相关性统计分析、机理竞争（证实π-π和络合机制）等多种途径深入揭示了生物炭对四环素和重金属离子去除的微观机制，研究发现功能性生物炭对四环素的主要去除机理是孔隙扩散、π-π作用、氢键和络合，对重金属离子的去除机理是络合、沉淀、离子交换和阳离子-π机制。.研究发现壳聚糖改性磁性多孔的生物炭、铁氮改性的生物炭、水热+KHCO3活化制备的多孔生物炭、 KOH/KMnO4改性的生物炭、KHCO3二次活化的生物炭、KOH二次活化的生物炭均是理化性质优异的功能性生物炭，对于废水中四环素和铜离子有着良好的去除效果，具有良好的应用潜力。.研究结果对于功能性生物炭的制备及畜禽养殖生化尾水中抗生素和重金属离子的污染控制具有重要意义。