基于可见光催化的腐皮镰刀菌灭活机制与光催化燃料电池研究
发布时间：2018-04-03 05:09
本文选题：活性物种 切入点：可见光 出处：《吉林大学》2017年硕士论文
【摘要】：城市污水在经处理后,水中的病原微生物仍大量存在,镰刀菌属广泛分布在水和土壤系统中,会引起植物根,茎和花的腐烂。但是,由于其具有较厚的细胞壁和较强的环境抗性,腐皮镰刀菌形成的孢子细胞非常难以失活。选择3种典型的掺杂型TiO_2,即Ag/TiO_2,N/TiO_2和Er~(3+):YAlO_3/TiO_2,对腐皮镰刀菌进行可见光催化灭杀,采用光学显微镜和透射电镜、三维荧光光谱、凝胶过滤色谱和掩蔽实验等手段,确定活性氧物种(ROSs)在镰刀菌的孢子灭活中的作用。结果表明,1)Ag/TiO_2光催化产生的ROSs主要是H2O_2,在不同种类的ROSs中具有最长的寿命。反应1 h后,Ag/TiO_2对腐皮镰刀菌灭活率接近100%,但失活的腐皮镰刀菌孢子仍保持完整细胞壁形状,生物分子渗漏最小化。2)Er~(3+):YAlO_3/TiO_2由h+占主导,反应7 h后的灭活率为91.0%,被灭活的腐皮镰刀菌细胞壁严重损伤,随后Er~(3+):YAlO_3/TiO_2纳米颗粒进入孢子细胞并继续氧化细胞内物质。3)N/TiO_2光催化剂产生的是以·O_2-为主的ROS,7 h后的腐皮镰刀菌孢子灭活率为94.3%,细胞壁形状改变,有细胞溶出物泄露。因而,H2O_2主导的ROS对于孢子灭活效果最佳。为了进一步实现有效杀灭腐皮镰刀菌孢子和能源的回收,本文对基于Ag/TiO_2的光催化燃料电池(PFC)进行了初探。采用旋涂法将Ag/TiO_2涂布到导电玻璃制备PFC光电阳极。通过对负载率分别为0.036、0.50、0.75和1.30 wt%电极的I-T曲线、COD去除率、库伦效率、极化功率密度虚线以及电池内阻进行测试,发现负载率为0.75 wt%的电极有最高的电化学特性,其组成的PFC体系在杀灭腐皮镰刀菌孢子的同时产生了稳定的电流,4 h后,发现PFC体系中只能检测到浓度比较低的腐皮镰刀菌孢子(50 CFU/m L),而单纯的光催化反应4小时后溶液中腐皮镰刀菌孢子的浓度为215CFU/m L,约为PFC体系中的4倍。
[Abstract]:After treatment of municipal sewage, pathogenic microorganisms still exist in the water. Fusarium is widely distributed in water and soil systems, which will cause rotting of plant roots, stems and flowers.However, due to its thick cell wall and strong environmental resistance, spores formed by Fusarium vulgaris are very difficult to inactivate.Three kinds of typical doped TiOs _ 2, namely, Ag- / TiO2N- / TiO-2 and Er~(3 / YAlO _ 3 / TiO2, were selected to kill Fusarium vulgaris by visible light catalytic killing, using optical microscope and transmission electron microscope, three-dimensional fluorescence spectrum, gel filtration chromatography and masking experiment, etc.To determine the role of reactive oxygen species (Ros) in spores inactivation of Fusarium.The results show that the ROSs produced by photocatalysis is mainly H _ 2O _ 2 and has the longest lifetime among different kinds of ROSs.After one hour of reaction, the inactivation rate of Ag- / TiO-2 to Fusarium vulgaris was close to 100, but the inactivated spores of Fusarium vulgaris remained intact cell wall shape, and bio-molecular leakage minimization.The inactivation rate was 91.0% after 7 h reaction. The cell wall of inactivated Fusarium vulgaris was seriously damaged.闅忓悗Er~(3 ):YAlO_3/TiO_2绾崇背棰楃矑杩涘叆瀛㈠瓙缁嗚優骞剁户缁哀鍖栫粏鑳炲唴鐗╄川.3)N/TiO_2鍏夊偓鍖栧墏浜х敓鐨勬槸浠ヂ稯_2-涓轰富鐨凴OS,7 h鍚庣殑鑵愮毊闀板垁鑿屽瀛愮伃娲荤巼涓，
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