• 关键词：壳聚糖/聚乙烯醇  静电纺丝  纳米纤维膜  重金属  吸附

• 基金项目：

• 张慧敏
• 华南理工大学土木与交通学院, 广州 510641

• 阮弦
• 华南理工大学化学与化工学院, 广州 510641

• 胡勇有
• 1. 工业聚集区污染控制与生态修复教育部重点实验室, 广州 510006;2. 华南理工大学环境与能源学院, 广州 510006

• 程建华
• 1. 工业聚集区污染控制与生态修复教育部重点实验室, 广州 510006;2. 华南理工大学环境与能源学院, 广州 510006

• 谭平
• 华南理工大学环境与能源学院, 广州 510006

• 摘要：采用SEM、FTIR、XRD、BET等技术对静电纺丝制得的吸附材料壳聚糖/聚乙烯醇(CS/PVA)纳米纤维膜进行表征,并通过对模拟重金属离子废水的吸附实验,系统考察了溶液pH、重金属离子(Cu²⁺、Ni²⁺及Cd²⁺)初始浓度和反应温度对吸附的影响.结果表明,在外加电压25 kV、接触距离15.0 cm、纺丝速度0.15 mL·h^-1的条件下,可制得CS/PVA质量比为20/80的连续无缺陷的平均直径76.31 nm、比表面积219.4 m²·g^-1的纤维膜.CS/PVA纳米纤维膜对重金属离子的吸附在2 h内达到平衡,其吸附容量随着温度的升高而升高,随着初始浓度的增大而增大,随着pH值的升高而提高,在pH=5.5时达到最大.在25 ℃和pH=5.5的条件下,用CS/PVA纳米纤维膜吸附浓度100 mg·L^-1的Cu²⁺、Ni²⁺和Cd²⁺溶液,吸附容量分别为98.65、116.89和124.23 mg·g^-1,且对重金属吸附无选择性.吸附过程符合Langmuir和Freundlich等温吸附模型,吸附动力学同时匹配准一级动力学模型和准二级动力学模型.热力学参数(ΔG、ΔH和ΔS)计算结果表明,CS/PVA纳米纤维膜对重金属离子的吸附是自发的吸热反应.

• Abstract：A novel adsorbent for heavy metals, chitosan/poly(vinyl alcohol) nanofiber,was prepared by electrospining and utilized for sorption of Ni(II), Cu(II) and Cd(II) ions from aqueous solutions. The prepared nanofibers were characterized by Scanning Electron Microscope(SEM), Fourier Transform Infrared(FTIR), X-ray diffraction(XRD) and Brunauer-Emmert-Teller(BET).The applied voltage, tip-collector distance and solution flow rate of the electrospinning process were 25 kV, 15.0 cm and 0.15 mL·h^-1, respectively.The nanofiber weight ratio of chitosan:poly(vinyl alcohol) was 20:80.Based on the results, the homogeneous electrospun nanofibers with the average diameter and surface area of 76.31 nm and 219.4 m²·g^-1 were obtained respectively. The adsorption equilibrium of CS/PVA on metal ions can be reached within 2 hours. Sorption capacities of CS/PVA onto metal ions increased with the increases of temperature, initial metal ion and pH and the optimum pH was determined as 5.5. The adsorption capacities of Cu²⁺, Ni²⁺ and Cd²⁺ by the chitosan/poly(vinyl alcohol) nanofiber were 98.65 mg·g^-1, 116.89 mg·g^-1 and 124.23 mg·g^-1, respectively at 25 ℃, pH 5.5 and initial heavy metal concentration of 100 mg·L^-1. The sorption process was found to follow pseudo-first-order and pseudo-second-order kinetic models and the adsorption isotherm was well described by Langmuir and Freundlich adsorption isotherm models. The calculated thermodynamic parameters (ΔG,ΔH and ΔS) showed that the adsorption of metal ions onto the PVA/Chitosan nanofiber membrane was feasible, spontaneous and endothermic.

• Key words：chitosan/PVA  electrospinning  nanofiber  metal ions  adsorption

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