al2o3pvdf负载nife催化还原剂制备及氯乙酸脱氯研究word格式论文.docxVIP

Classified Index: X703 U.D.C: 628.1Dissertation for the Master Degree in EngineeringSTUDY ON THE PREPARATION OF Al2O3/PVDF SUPPORTED Ni/Fe CATALYTIC REDUCTANT AND THE DECHLORINATION OF CHLOROACETIC ACIDCandidate:Deng HuijuanSupervisor:Prof. Liu HuilingAcademic Degree Applied for:Master of EngineeringSpeciality:Environmental Sci. and Eng.Affiliation:School of Muni.and Env. EngDate of Defence:June, 2013Degree-Conferring-Institution:Harbin Institute of Technology摘要氯代有机物具有分布广泛、危害严重、难降解、毒性大等特点，是许多国家 的优先控制污染物。在零价铁的研究基础上，负载型的纳米级含铁双金属作为催 化还原剂，具有活性高、成本低、污染小等优点。本文以 Al2O3·PVDF 为载体，负 载 Ni/Fe，进行催化剂的制备、表征，并分析氯乙酸脱氯的影响因素。本文采用浸渍法，在 PVDF 基体改性的基础上，制备 Ni/Fe/Al2O3·PVDF 催化 还原剂。负载 Ni/Fe 还原剂的制备过程中，考察交联液配比及交联时间、不同浓度 硫酸镍浸渍时间、镍铁比等因素。通过载铁量、氯乙酸脱氯效果等结果优化制备 工艺。通过扫描电镜对 Ni/Fe/Al2O3·PVDF 催化还原剂表征，观察优化条件下制备出 的载体表面形貌，并对元素成分定性分析。结果表明，制备出的双金属在膜载体 表面及断面分布均匀，呈球状和片状结构且双金属未发生团聚，能谱分析结果进 一步证明 Ni 和 Fe 覆盖在 Al2O3·PVDF 膜的表面。以一氯乙酸为目标物，考察还原剂投加量、反应初始 pH、共存离子、水的影响、反应温度、摇床转速、初始浓度、还原剂存放时间等因素对一氯乙酸降解效 果的影响，对于三氯乙酸，研究初始浓度的对降解效果的影响，分析其降解过程 和机理。研究载体的保存时间和循环使用次数，结果表明制得的膜载体具有一定的稳 定性。载体在无水乙醇中保存 30 天，活性几乎保持不变。实验室自制的纳米镍铁 PVDF 膜，可以循环使用 3 次，对氯乙酸可以保持较优的脱氯效果。考察初始浓度以及投加量，对 MCAA 和 TCAA 进行动力学研究，结果证明MCAA 和 TCAA 的降解反应均符合准一级反应。关键词：还原脱氯；载体 Al2O3·PVDF；氯乙酸；纳米 Ni/Fe-I-AbstractChlorinated organic compounds are widely distributed, seriously harmful, difficult to be degraded and with high toxicity, so they have been named as priority control of pollutants in many countries. Based on the study of zero-valent iron, supported nanoscale iron bi-metallic are used as catalytic reducing agent, with the advantages of high activity, low cost and low pollution .In this paper, Al2O3·PVDF was used as the carrier, Ni/Fe were immobilized . The preparation and characterization of catalyst, factors that affected dechlorination of chloroacetic acid were investigated.Impregnation method was used to prepare Ni/Fe/Al2O3·PVDF catalytic reductant based on matrix modification of PVDF. Crosslinking liquid ratio and crosslinking time、dipping time in different nickel