调控黄钾铁矾粒径提高其类芬顿催化活性的研究

摘要：自然环境中的黄钾铁矾主要是由铁氧化细菌Acidithiobacillus ferrooxidans催化氧化Fe2+形成，生物合成的黄钾铁矾可以催化类芬顿反应降解有机污染物，但对其粒径如何影响其催化效率仍不清楚不高。本研究通过调控生物法合成时间制备了两种不同粒径的黄钾铁矾，以SEM、XRD和BET方法对其进行表征，并将其作为类芬顿催化剂降解苯酚来探究黄钾铁矾粒径差异对黄钾铁矾类芬顿催化活性的影响。结果表明，成矿1 d比成矿10 d的黄钾铁矾粒径小，比表面积大。两种黄钾铁矾都可在较宽pH (3.0-7.0)范围内高效催化类芬顿反应降解苯酚，且降解过程都先后存在诱导阶段和快速降解阶段。成矿1 d的黄钾铁矾因诱导期短，反应速率高，H2O2利用率高而比成矿10 d的黄钾铁矾具有更高的催化活性。基于溶出铁和苯酚浓度的分析，在诱导期两种类芬顿体系催化反应主要发生在矿物表面。26212
毕业论文关键词：类芬顿；黄钾铁矾；粒径；比表面积；催化活性
Research of Improving the Catalytic Activity of Jarosite by Regulating and Controlling the Diameter of Particle
Abstract：Jarosite can be biosynthesized by Fe-oxidizing bacterium Acidithiobacillus ferrooxidans and the influence of particle size on its catalytic activity in heterogeneous Fenton-like reactions is still unclear. In the present study, the catalytic activities of two biosynthesized jarosite harvested in 1 and 10 days of incubation, respectively, were compared through investigating the heterogeneous Fenton-like degradation of a target organic pollutant, phenol. Results showed that these two catalysts efficiently catalyzed heterogeneous Fenton-like degradation of phenol in a wide pH range (pH 3.0-7.0), and the degradation in both systems consisted of an induction period (first-stage) and a followed rapid degradation stage (second-stage). Jarosite-1d exhibited a much higher catalytic capacity than jarosite, because of its shorter induction period, higher kinetic rate (k) of the second-stage and greater utilization efficiency of H2O2. Based on the results of Fe leaching and phenol degradation, similar catalytic mechanisms were proposed in jarosite-1d/H2O2 and jarosite-10d/H2O2 systems, in which the heterogeneous Fenton-like Reactions was dominant in the induction period of phenol degradation.
Keywords：Fenton-like reaction；Jarosite；Particle；Specific area；Catalytic activity
目录
摘要3
关键词…3
Abstract3
Key words …3
绪论3
1 材料与方法5
1.1 不同粒径黄钾铁矾的制备…5
1.1.1 Acidithiobacillus ferrooxidans休止细胞的制备 5
1.1.2 不同粒径黄钾铁矾的生物法制备…5
1.2 黄钾铁矾的表征…5
1.2.1 XRD分析 …5
1.2.2 SEM分析 …5
1.2.3 BET分析 …5
1.3 黄钾铁矾催化H2O2降解苯酚的实验5
1.3.1 初始H2O2浓度对苯酚降解的影响实验 5
1.3.2 初始pH对苯酚降解的影响实验 …6
1.3.3 矿物投加量对苯酚降解的影响实验6
1.3.4 测定反应体系中Fe2+、TFe、H2O2和TOC的测定 6
1.4 测定方法与仪器…6
2 结果与分析7
2.1 黄钾铁矾的表征结果…7
2.2 初始H2O2浓度对苯酚降解的影响 …8
2.3 初始pH值对苯酚降解的影响 …9
2.4 矿物投加量对苯酚降解的影响 12
2.5 类芬顿体系中Fe2+、TFe、H2O2的变化…14
2.6 类芬顿体系中TOC的去除效果15
3 结论 16
致谢 …17
参考文献 …17
调控黄钾铁矾粒径提高其类芬顿催化活性的研究
绪论
近年来，工业的迅速发展导致大量的有机污染物产生，这些存在于废水中的有机污染物具有排放量大和难降解等特点，对人类及环境的危害极大，因此治理难降解的有机污染物备受社会重视。芬顿氧化技术因其反应过程中产生的•OH具有高氧化特性和无选择性的特点，在有机废水处理领域备受关注。然而，芬顿氧化反应存在易产生铁泥、H2O2利用率不高、反应pH要求严格等缺点。类芬顿氧化技术是近年来研究较多的一种高级氧化处理技术，也是在芬顿氧化技术的基础上加以改进而得的新型技术。调控黄钾铁矾粒径提高其类芬顿催化活性的研究:http://www.youerw.com/huaxue/lunwen_20311.html