Development of gas decontamination system using thermo-responsive polymer

燃烧气体包括多种环境污染物，如多环芳烃(PAHs)和醛。它们具有毒性和生物蓄积性，因此必须有效清除。本研究通过有机污染物对热敏性聚合物水溶液的增溶作用、聚合物热响应性沉积物的萃取和浮选技术对聚合物沉积物的收集，开发了一种简单高效的气体净化系统。使用具有较低临界溶解温度(约32℃)的水溶性聚合物聚(N-异丙基丙烯酰胺)[PNIPAAm]。在PNIPAAm存在下，燃烧气体中的多环芳烃被有效地转移，然后通过气体通过溶液而被溶解在水溶液中。研究发现，PNIPAAm对疏水性多环芳烃具有增溶作用。通过加热溶液，PNIPAAm是水不溶的，并被沉积。伴随着Polyme…R沉积较多，芳环数大于3的多环芳烃占主导地位。这归因于多环芳烃在水合聚合物组件中的掺入。采用气浮技术，可将高浓度污染物的聚合物沉积物快速收集到水面上。添加少量的盐、表面活性剂和乙醇可以有效地改善有机污染物和聚合物沉积物的收集。考察了柱高、聚合物浓度、气体和聚合物溶液进料量、温度、空气流量等因素对分离效果的影响。将增溶到聚合物水溶液和随后的聚合物介体萃取相结合，用于气体样品中有机污染物的痕量分析。由于将高灵敏的荧光检测与聚合物介导的浓缩相结合，在极短的时间(通常为20 S)内采样的环境空气样品中的醛成功地被测定到亚ppb水平。该方法能够对空气中亚ppb水平的有机污染物进行时间分辨监测。较少

Combustion gas includes several environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs) and aldehydes. They are toxic and bioaccumulative and thus have to be effectively removed. In the present study, a simple and efficient gas decontamination system was developed by the combination of the solubilization of organic pollutants to the aqueous solution of thermo-responsive polymer, the extraction based on the thermo-responsive deposit of the polymer, and collection of the polymer deposits by the flotation technique. A water-soluble polymer, poly (N-isopropylacrylamide) [PNIPAAm], having a lower critical solution temperature (ca. 32°C) was used. In the presence of PNIPAAm, PAHs in combustion gas were effectively transferred and then solubilized in the aqueous solution by passing the gas through the solution. PNIPAAm was found to act as a solubilizing agent for hydrophobic PAHs. By warming the solution, PNIPAAm was water-insoluble and deposited. Accompanying with the polyme … More r deposit, PAHs having more than three aromatic rings were predominantly collected. This was ascribed by the incorporation of PAHs into the hydrated polymer assemblies. The polymer deposits containing highly concentrated pollutants were rapidly collected on water surfaces by the flotation technique. The addition of small amounts of salt, surfactant, and ethanol was effective for improving the collection of organic pollutants and polymer deposits. Several factors including column height, polymer concentration, feeds of gas and polymer solution, temperature, air flow, etc. were investigated. The combination of the solubilization into the aqueous polymer solution and the subsequent polymer-mediated extraction was applied to the trace analysis of organic contaminants in gas samples. Because of the combination of highly sensitive fluorescent detection with polymer-mediated concentration, sub-ppb levels of aldehydes were successfully determined in the ambient air samples that had been sampled in extremely short (typically 20 s) time. The method enabled time-resolved monitoring of sub-ppb levels of organic pollutants in air. Less