纸基吸附-分离材料的制备及其应用性能

Preparation and Application of Paper-based Adsorption-Separation Materials

中文关键词:  纸基吸附-分离材料  高湿强度  重金属离子  吸附  油水分离

Key Words:paper-based adsorption-separation materials  high wet strength  heavy metal ions  adsorption  oil-water separation

中文摘要:

      以杨木化机浆为原料，以柠檬酸（多元酸）为改性剂，基于造纸工艺技术，制备了低成本、易回收、高重金属离子吸附容量和高效油水分离的木质纤维纸基吸附-分离材料。柠檬酸改性可同时提高木质纤维之间的交联程度和羧基含量，进而提高纸基吸附-分离材料的湿强度和增加重金属离子吸附位点。研究结果显示，纸基吸附-分离材料的湿抗张指数可达其干抗张指数的40%~50%，羧基含量最高可达0.66 mmol/g。随柠檬酸浓度提高，纸基吸附-分离材料对重金属离子的吸附容量显著提高，其吸附动力学和热力学均很好地拟合了准二级方程和Langmuir模型（相关系数R²≥0.998），对Cu²⁺和Pb²⁺的理论最大吸附容量分别达到44.29和132.1 mg/g。此外，高羧基含量使纸基吸附-分离材料亲水性显著增强，并赋予其优良的油水分离性能，最大水下油接触角可达155°以上，油水分离效率可达99.8%以上。该多功能纸基吸附-分离材料克服了传统吸附剂和油水分离材料的缺点，可同时进行高效的重金属离子吸附去除和油水分离，并且具备了大规模生产的潜力，在工业废水处理领域具有重要的应用前景。

Abstract:

      Based on papermaking technology， paper-based adsorption-separation material with low cost， reusability， high adsorption capacity on heavy metal ions， and high efficiency on oil-water separation was prepared using poplar chemical pulp as raw material and citric acid as modification reagent. The treatment of citric acid increases both the crosslinking degree between fibers and carboxyl group content， thus improving the wet strength and increasing the adsorption sites of heavy metal ion of the paper-based adsorption-separation materials. The results showed that the wet tensile index of the paper-based adsorption-separation materials was 40%~50% of their dry tensile index， and the maximum carboxyl group content reached 0.66 mmol/g. With an increase in the concentration of citric acid， the adsorption capacities of heavy metal ions increased significantly. The adsorption kinetics and thermodynamics well fitted the quasi-second-order equation and Langmuir model （correlation coefficient R²≥0.998）， and the theoretical maximum adsorption capacity of the paper-based adsorption-separation materials on Cu²⁺ and Pb²⁺ reached 44.29 and 132.1 mg/g， respectively. Moreover， the hydrophilicity of the adsorption-separation materials was favored by its high carboxyl group content， endowing it with excellent oil-water separation property （with the maximum underwater oil contact angle >155°， separation efficiency of 99.8%）. It was therefore concluded that the low-cost paper-based adsorption-separation materials could remove heavy metal ion and separate oil and water simultaneously， and was of an important application prospect in the field of industrial wastewater treatment.