磁性聚吡咯基材料制备及对印染废水中Cr(Ⅵ)吸附特性研究

Preparation of Magnetic Polypyrrole Based Material and Its Adsorption Characteristics for Cr(Ⅵ)in Textile Wastewater

首先通过原位氧化聚合法制备富氮聚合物(PPy),然后以PPy前体和磁性金属粉末在高温条件下成功制备出两性吸附剂CN@Co_(3)Fe _(7)。利用扫描电镜(SEM)、红外光谱(IR)、X射线衍射仪(XRD)和透射电镜(TEM)等多种手段对合成吸附材料进行了形貌和结构表征,并系统考察了其对纺织印染废水中Cr(Ⅵ)的吸附性能。试验结果表明:制备出的纳米吸附材料呈六方块结构,粒径为150 nm,饱和磁化强度约49.1 emu/g,对Cr(Ⅵ)具有良好的吸附能力,在吸附剂用量为4 mg/L、pH 1.7、Cr(Ⅵ)初始浓度为200 mg/L的条件下吸附1 h,对Cr(Ⅵ)去除率可达99.48%,3次再生后去除率仍可维持在83.41%。吸附动力学规律遵循准一级动力学模型,而吸附等温线符合Freundlich等温吸附模型,说明吸附是一个多层不均匀吸附。

Nitrogen-rich polymer(PPy)was firstly prepared by in-situ oxidation polymerization and then amphoteric adsorbent CN@Co_(3)Fe_(7) was successfully prepared from PPy precursor and magnetic metal powder.Morphology and structure of the synthesized adsorbent were characterized by scanning electron microscopy(SEM),infrared spectroscopy(IR),X-ray diffractometer(XRD)and transmission electron microscope(TEM).Its adsorption properties for Cr(Ⅵ)in textile printing and dyeing wastewater were systematically investigated.The test results showed that the prepared nano adsorbent had a hexagonal structure with a particle size of about 150 nm.Saturated magnetization was about 49.1 emu/g.It had good adsorption capacity for Cr(Ⅵ).Removal rate of Cr(Ⅵ)could reach 99.48%after 1 h adsorption under the conditions that the amount of adsorbent was 4 mg/L,pH 1.7 and the initial concentration of Cr(Ⅵ)was 200 mg/L,and the removal rate could still be maintained at 83.41%after three regenerations.The adsorption kinetics followed the quasi first order kinetic model.The adsorption isotherm showed that the adsorption law conforms to the Freundlich isotherm adsorption model,indicating that the adsorption was a multi-layer heterogeneous adsorption.