油茶果壳水热碳化制备全氟化合物表面印迹微球及其吸附性能

This project aimed to explore a new efficient absorbent for treatment of perfluorinated persistent organic pollutants in water prepared by an environmental friendly method from a cheap agricultural wastes as raw material. The preparation method of new adsorbent mainly consisted of three steps: first, porous carbon microspheres that were size adjustable, large specific surface area and high mechanical strength were prepared by hydrothermal carbonization technology with the fruit shell of camellia oleifera Abel. as raw materials. Then active free radicals were introduced and bi-monomers was initiated for copolymerization and crosslinking on the surface of microspheres with the porous carbon microspheres as supporter, perfluorooctanoic acid or perfluorooctane sulfonate as template molecule, an unsaturated ester with cationic group and an unsaturated acid polyfluoroalkyl ester as bi-monomers. Finally, template molecules were removed and surface imprinted carbon microspheres as absorbent were obtained. In order to obtain high-performance carbon microsphere absorbents, the morphology, particle size and specific surface area of carbon microspheres were investigated under different hydrothermal carbonization conditions, the surface grafting efficiency and adsorption properties of the microspheres were studied under different initiator and polymerization conditions, and its adsorption characteristics and recognition mechanism for the template molecule were investigated. The above study could provide scientific evidence for developing new technologies for high-value utilization of fruit shell of camellia oleifera Abel. and highly efficient treatment of perfluorinated persistent organic pollutants.

针对环境介质中普遍存在的全氟代持久性有机污染物难于有效治理的问题，本项目探索一种以价廉易得的农林废弃物为原料制备绿色高效水处理吸附剂的环境友好新方法。该新型吸附剂的制备方法主要包括三个步骤：首先以油茶果壳为原料，通过水热炭化技术制备尺寸可调、比表面积大、机械强度高的多孔炭微球；然后，以多孔炭微球为载体，以全氟辛酸或全氟辛烷磺酸为模板分子，以含阳离子基团的不饱和酸酯和不饱和酸多氟代烷基酯为联合功能单体，通过在微球表面引入活性自由基，引发二元单体在微球表面进行共聚和交联；最后，将模板分子洗脱，获得表面印迹炭微球吸附剂。为了获得高性能的炭微球吸附剂，重点研究不同水热炭化条件对炭微球形貌、粒径和比表面积等性能的影响，研究不同引发剂和聚合条件对微球表面接枝效果和吸附性能的影响，研究吸附剂对模板分子的吸附特性和识别机理。为开展油茶果壳高值化利用和全氟代持久性有机污染物治理新技术研究提供科学依据。

本项目旨在探索一种对油茶果壳高值化利用的新途径和新技术，为进一步开展油茶果壳高值化利用新技术及应用研究提供科学依据。具体完成了三个方面的研究工作：1）采用低温水热法制备了油茶果壳胶质炭微球，通过KOH活化和高温退火等改性方法，制备了一系列多孔碳材料；通过在水热反应中加入助剂，提高了胶质炭微球的产率，并大大减少了微球中的杂质，通过高温退火和KOH活化等改性方法，制备了一系列形貌较好的多孔炭微球。 2）以上述所制备表面富含羟基官能团的胶质炭微球为核，以PFOS为模板分子，制备了基于炭微球的表面印迹材料，对材料进行了表征，考察了印迹碳微球对PFOS的吸附动力学和吸附等温线，考察了印迹材料对PFOS的吸附选择性及再生吸附性能。基于低温水热炭微球的制备方法，在反应原料中加入PFOS，通过一步水热法制得PFOS印迹碳微球，对材料进行了表征，考察了其对PFOS的吸附动力学和吸附等温线，并考察了不同活化温度对吸附容量的影响。并基于对以上吸附剂的结构表征和吸附性能研究结果，初步阐述材料对目标分子的吸附机理。3）将上述所制备多孔碳材料和炭微球应用于水中PFOS、染料、重金属及典型酚类化合物的吸附去除和性能研究。研究了吸附动力学和吸附等温线，及pH对吸附的影响，并对其吸附机理进行了初步探讨。. 本研究制备的油茶籽壳多孔炭材料和炭微球为多种典型污染物的吸附去除提供了新的高效吸附剂；基于炭微球所制备的PFOS表面分子印迹材料和一步印迹材料，弥补了传统吸附剂材料选择性不够，传质速率慢、吸附剂成本高和吸附剂本身难以降解等缺陷，为高效去除水体中持久性有机污染物PFOS制备了又一种新型生物质基功能炭材料。这些均为废弃的油茶籽壳生物质高值化利用开辟了新途径。