互穿网络海藻酸盐凝胶球的制备及其吸附水中磷酸盐性能研究

发布时间：2018-04-16 17:31

本文选题：凝胶球 + 吸附　；参考：《广州大学》2017年硕士论文

【摘要】：随着人类工农业生产和生活的快速发展,含磷废水由于某些原因未经处理或未达标就排入水体,可能造成水体富营养化问题。然而,随着自然界有限磷资源的日益减少,污水中的磷对于农业肥料生产却是一种重要的资源。因此,开发一种实现废水中磷的有效去除和回收的经济、高效技术显得迫在眉睫。在众多废水除磷技术中,吸附法因其独特的优势受到人们的重视,而吸附剂的选择对处理效果具有决定性的影响。传统吸附剂材料大多存在成本高、吸附容量较低、不可降解及循环利用性较差等问题,为此本课题开发一种低成本、高吸附能力、易重复使用且环境友好的互穿网络海藻酸盐凝胶球用作新型除磷吸附剂,为利用吸附技术解决污水中磷的有效去除和回收再利用提供新的思路和理论基础,同时拓展高分子材料在环境领域的应用。本文通过化学交联法制备互穿网络聚N-异丙基丙烯酰胺/海藻酸锆(PNIPAM/SA-Zr)凝胶球和磁性聚丙烯酰胺/海藻酸锆(Fe3O4@PAM/SA-Zr)凝胶球,使用扫描电镜、傅里叶变换红外光谱和X射线光电子能谱等手段对其物化性质进行表征,通过人工配制含磷废水研究其吸附磷酸盐的性能,探讨其吸附动力学、等温线和热力学以研究吸附机理,并考察凝胶球的解吸附、再生及重复使用性能和固定床吸附柱的吸附性能,以期为海藻酸盐凝胶球吸附剂的实际应用提供理论依据。本文取得的主要研究结果如下:(1)表征结果表明制备的PNIPAM/SA-Zr和Fe3O4@PAM/SA-Zr凝胶球聚合形态良好,呈球形,具有大孔隙或孔洞,热稳定性和机械性能良好;特别的,Fe3O4@PAM/SA-Zr凝胶球具有磁性,在磁场作用下很容易实现分离。(2)静态批次试验结果表明:PNIPAM/SA-Zr凝胶球吸附磷酸盐的最佳条件为溶液pH=2,投加量0.05 g,温度35℃,其最大吸附量为36.63 mg-P/g;Fe3O4@PAM/SA-Zr凝胶球吸附磷酸盐的最佳条件为溶液pH=2,投加量0.05 g,温度25℃,其最大吸附量高达42.23 mg-P/g;增加Zr4+含量可以显著提升凝胶球的吸附能力;SO42-的存在不利于凝胶球吸附磷酸盐,而Cl-和NO3-几乎没有影响;凝胶球具有良好的循环使用能力,7次吸附-解吸附循环后球体结构保持完整。(3)磷酸盐在PNIPAM/SA-Zr和Fe3O4@PAM/SA-Zr凝胶球上的吸附过程符合准二级动力学模型和颗粒内部扩散模型以及Freundlich吸附等温模型,表明其受表面吸附和颗粒内扩散机制的联合控制,且是一种多分子层、非均相吸附过程。吸附热力学研究表明其可自发进行,为放热反应,吸附后整个体系的混乱度降低。(4)PNIPAM/SA-Zr和Fe3O4@PAM/SA-Zr凝胶球吸附磷酸盐受物理吸附和化学吸附共同作用,其反应机理为被固化的Zr4+与磷酸根离子发生了配位络合反应,生成化学键。此外,凝胶球表面的羟基、亚氨基和氨基在酸性条件下发生质子化而带正电,在静电力作用下,吸附带负电的磷酸根离子。(5)PNIPAM/SA-Zr和Fe3O4@PAM/SA-Zr凝胶球动态吸附试验表明:进水流速过大或进水浓度过高会降低吸附柱的吸附效果,应根据实际情况确定。
[Abstract]:With the rapid development of industrial and agricultural production and human life, phosphorus wastewater for some reason untreated or standard is discharged into the water, may cause eutrophication problems. However, with the limited nature of phosphorus resources dwindling, phosphorus in the wastewater for agricultural fertilizer production is an important resource. Therefore, the development of a for effective removal of phosphorus in wastewater and recycling economy, high technology is imminent. In many wastewater phosphorus removal technology, adsorption attention because of its unique advantages, and the selection of the adsorbent for treatment effect has a decisive impact. The traditional adsorbent materials are of high cost, low absorption capacity no, the problem of degradation and poor circulation utilization, this paper developed a kind of low cost, high adsorption capacity, alginate interpenetrating network easy to use and environmental friendly The ball is used as a new phosphorus adsorbent, to provide new ideas and theoretical basis for the effective removal and recovery of phosphorus from wastewater by using adsorption technology to solve the reuse, while expanding application of polymer materials in the field of the environment. This paper was prepared by chemical crosslinking of IPN poly N- isopropyl acrylamide / zirconium alginate (PNIPAM/SA-Zr) gel ball and the magnetic polyacrylamide / alginate gel ball, zirconium (Fe3O4@PAM/SA-Zr) using scanning electron microscopy, Fu Liye transform infrared spectroscopy and X ray photoelectron on their physicochemical properties were characterized by means of spectroscopy, artificial wastewater containing phosphorus on the performance of the adsorption of phosphate, investigate its adsorption kinetics, isotherms and thermodynamics to study the adsorption mechanism, adsorption solution and the effects of gel balls adsorption, regeneration and reuse performance and fixed bed adsorption column, in order to actual alginate gel ball adsorbent should be Used to provide a theoretical basis. The main research results are as follows: (1) the characterization results show that the prepared PNIPAM/SA-Zr and Fe3O4@PAM/SA-Zr gel polymerization forms a good spherical shape, with large holes, good thermal stability and mechanical properties; in particular, Fe3O4@PAM/ SA-Zr gel ball with magnetic, under magnetic field is very easy to implement the separation. (2) the static batch test results show that the optimum conditions of PNIPAM/SA-Zr gel balls adsorption phosphate solution is pH=2, the dosage of 0.05 g, temperature 35, the maximum adsorption capacity is 36.63 mg-P/g; the best conditions for Fe3O4@PAM/ SA-Zr gel balls adsorption phosphate solution is pH=2, the dosage of 0.05 g, temperature 25 degrees. The maximum adsorption capacity of up to 42.23 mg-P/g; the adsorption capacity increased the content of Zr4+ can significantly improve the gel ball; SO42- is not conducive to the existence of gel balls adsorption of phosphate, Cl- and NO3- have little effect; gel ball Have good recycling ability, 7 adsorption desorption cycles, the sphere structure remained intact. (3) PNIPAM/SA-Zr and Fe3O4@PAM/SA-Zr in the adsorption process of phosphate gel ball on pseudo two order kinetics model and particle diffusion model and Freundlich adsorption isotherm model, combined control shows that the surface adsorption and intra particle diffusion the mechanism, and is a kind of multi molecular layer, heterogeneous adsorption process. The adsorption thermodynamics results show that it can be spontaneous, exothermic reactions, reduce the confusion degree after adsorption system. (4) PNIPAM/SA-Zr and Fe3O4@ PAM/SA-Zr gel balls adsorption of phosphate by physical adsorption and chemical adsorption, the reaction mechanism is the complexation reaction of Zr4+ and phosphate ion curing, chemical bond was formed. In addition, the gel ball surface hydroxyl, amino and imino under acidic conditions and protonation Positively charged, adsorbing negatively charged phosphate ions under electrostatic force. (5) dynamic adsorption experiments of PNIPAM/SA-Zr and Fe3O4@PAM/SA-Zr gel balls indicate that excessive influent velocity or excessive inlet water will reduce the adsorption effect of adsorption column, and should be determined according to the actual situation.

【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

【参考文献】