聚合物基离子液体掺杂nZVI柱撑层状钛酸盐制备及其快速富集和降解水中TBBPA的研究：吸附形态及还原途径

Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardant around the world. TBBPA is of high concern since it is a toxic and persistent compound which can be an endocrine disruptor. Therefore, it is necessary and significant to develop effective techniques to remove TBBPA from the contaminated environment. Owing to the lipophilicity, Low concentrations of TBBPA in real water samples make direct determination and treatment difficult. It was reported that Ionic liquid [C6MIM][PF6] could enrich TBBPA rapidly from real water samples. However, the combination mechanism between existing species of TBBPA and ionic liquid is still unknown. Moreover, the extracted species may affect the degradation pathways of TBBPA significantly. On the other hand, it is well known that nano Zero valent iron (nZVI) can drive reduction of many contaminants in the environment, such as chlorinated organics. The reactivity of the Fe0/Fe2+, with a standard potential of -0.447 V, has been attributed to its ability to drive reduction of chlorinated organics. However, the poor dispersion and reactivity available in aqueous environment could be one of critical points which hinder the application of nZVI as an effective technology for treatment. Therefore, our research group intends to combine the units of sensitive adsorption and effective degradation for treatment of low concentrations of TBBPA from polluted water. The composite polymer beads (Polymer/ILs@nZVI/MTLO) based ionic liquids encapsulated pillared layered titanate with nZVI will be prepared and the mechanism of sensitive adsorption driven effective degradation will be discussed. To our best knowledge, this mechanism has not been reported before. It is hypothesised that nZVI reductively deposited on layered titanate may play an important role in improving their diversity and enhance the reactivity. When TBBPA from bulk solutions passes through the pores of the composite beads (Polymer/ILs@nZVI/MTLO), they would be enriched rapidly by ionic liquid, [C6MIM][PF6]. And then nZVI immobilized on layered titanate with good dispersion and high reactivity would reduce them effectively. Conversely, this process would promote the transport of TBBPA from the bulk solutions to the surface of composite beads (Polymer/ILs@nZVI/MTLO). To prove this hypothesis, the distribution of TBBPA species will be determined by UV-Vis spectrophotometer and FT-IR spectrum. Furthermore, the pathway of TBBPA degradation on the composite beads will be involved so that a new idea for removal of organic pollutants with low concentrations from polluted water will be provided.

四溴双酚A（TBBPA）是潜在的内分泌干扰物，由于其可能引起生态安全问题而备受关注。研究表明，离子液体[C6MIM][PF6]可以快速富集水中痕量TBBPA，但是通过何种作用机制尚不清楚，而TBBPA的富集形态对降解途径有重要的影响。另一方面，虽然环境技术中常用的纳米Fe0(nZVI)可降解水中有机污染物，但低分散性与活性可利用性是阻碍其应用的关键问题。本课题组拟结合敏感吸附组元与高效降解组元，制备聚合物基[C6MIM][PF6]掺杂nZVI柱撑层状钛酸盐复合微球，初步探讨以敏感吸附促进的TBBPA高效还原机理，而这一机制目前尚无报道。我们推测在层状钛酸盐上沉降nZVI可有效改善其分散性从而提高活性点位，为证实该假说，本研究将利用分光光度计结合红外光谱分析TBBPA在[C6MIM][PF6]上的吸附形态，初步探讨其降解途径，为水溶液中微量有机污染物的去除提供新思路。

新兴有机污染物如四溴双酚 A(tetrabromobisphenol A, TBBPA)， 在自然条件下很难分解，是潜在的内分泌干扰物且容易在环境及生物体内累积，被认定是一种新的持久性有机污染物 (POPs)。TBBPA 污染和重金属离子污染引起的环境和生态安全问题已受到了社会各方面的极大关注。而由于生物分子多巴胺和葡萄糖与某些疾病有紧密的相关性，检测其在生物体内的微量含量是极其重要的。 因此开展对于环境中污染物的去除和检测技术的基础研究有重要的意义。本项目的主要研究内容包括：1. 快速制备自激活介孔纳米催化剂Fe0/MnxFeyO@C快速降解水中的TBBPA，结果发现单独使用Fe0, Fe(II) 或者 MnFe2O4降解水溶液中的TBBPA，两小时以后只有不超过5%的TBBPA被降解，而Fe0/MnxFeyO@C则可以在5分钟内分解接近99%的TBBPA。其去除机理包括物理吸附，电化学还原和化学氧化；2. 制备葡萄糖氧化酶固定化石墨烯纳米片-PDA/MOF微囊用于电化学检测葡萄糖。使用CaCO3模板构筑的PDA和ZIF-8微囊可以作为生物兼容性良好，无毒的载体固定化GOx。同时ZIF-8具有类过氧化酶的性质，而负载的石墨烯纳米片则加速微囊和电极之间的电子转移。因此建立起一个模拟的多酶体系，并且此生物传感器体系在实际样品的葡萄糖检测中表现出很好的选择性和较低的检测限；3. ATRP法制备新型TETA功能化的磁性PGMA纳米吸附剂用于高效吸附Hg2+。用FTIR, TEM，元素分析和VSM对此纳米吸附剂进行了表征。批试验表明此纳米吸附剂对于Hg2+有极高的吸附容量（543 mg/g）和去除率（99.7%）。同时在共存金属离子溶液中表现出很好的选择性和再生性能; 4.制备磁性Fe3O4@MOF修饰石墨烯纳米杂化物作为新型电化学检测器用于多巴胺的超敏感检测。将磁性Fe3O4@MOF修饰石墨烯纳米杂化物修饰到玻璃碳电极上用于检测磷酸缓冲溶液中的多巴胺，最低检测限为6.6710-10 M。并且，此传感器在维生素C和尿酸溶液中表现出对多巴胺有很好的选择性。