【作者】 陈杰；

【导师】 沈锦优；

【作者基本信息】 南京理工大学 ， 环境工程， 2021， 硕士

【摘要】 具有“三致效应”和遗传毒性的卤代酚类化合物在生产及使用过程中对环境水体污染严重,传统的生物处理技术很难对其有效处理。因此,开发新型、高效和绿色的具有实际应用意义的处理方法意义重大。本文以对溴苯酚（4-Bromophenol,4-BP）为主要目标污染物,制备了以g-C₃N₄和BiVO₄为主要材料的p-n异质结复合半导体催化剂,并将其负载到不同的载体,构建光催化耦合生物同步降解体系（Intimately Coupled Photocatalysis and Biodegradation,ICPB）。研究成果如下:通过浸渍共沉淀法成功制备了B掺杂g-C₃N₄/BiVO₄（BVCN）复合光催化剂。结果表明,与纯n型BiVO₄和p型B掺杂的g-C₃N₄相比,p-n异质结光催化活性大大增强。B掺杂的g-C₃N₄/BiVO₄异质结构表现出最佳的光催化降解活性,比BiVO₄高2.3倍,通过扫描电子显微镜、X射线衍射和XPS等测试,证实BVCN复合光催化剂中存在单斜BiVO₄和四方BiVO₄的混合相,混合相BiVO₄的形成归因于高温煅烧和B掺杂的g-C₃N₄表面化学能,BiVO₄和B掺杂的g-C₃N₄之间形成了异质结来降低光生载流子的复合率。紫外漫反射和光催化降解实验证明BVCN复合光催化剂拥有增强的光吸收能力和出色的光催化效果。将BVCN复合光催化剂分别负载于碳纸、石墨毡、聚氨酯三种不同的载体,构建光催化耦合生物系统强化处理对溴苯酚（4-BP）模拟废水,探究不同的载体对ICPB体系的影响。结果表明,以聚氨酯作为载体时,载体内部附有更密集的生物膜,在光催化和生物的协同作用下,反应36 h后4-BP的去除率为100%,与单独光催化相比4-BP的降解速率提高了50%。并且与碳纸和石墨毡相比,在反应24 h时聚氨酯系统的矿化效率为51.11%,而碳纸和石墨毡的矿化效率分别为13.8%和31.51%。对比进水和三个系统出水的三维荧光谱图可知,聚氨酯载体系统对污染物的降解最为彻底。在聚氨酯作为载体的系统中,溴酚降解功能菌（Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium和Pseudomonas）,生物絮凝功能菌Terrimonas得到明显富集。最后,提出了B-掺杂g-C₃N₄/BiVO₄耦合生物降解体系对4-BP可能的降解机理。基于B掺杂g-C₃N₄/BiVO₄的ICPB系统与单一光降解和生物处理相比,对4-BP展现出优异的吸附降解以及矿化效果,在难生物降解卤代酚物质的去除方面具有实际应用能力。更多还原

【Abstract】 Due to the teratogenicity,carcinogenicity,mutagenicity and genotoxicity characters of halogenated phenols compounds in chemical processing,conventional biological treatment technology could not effectively degrade toxic contaminants.It is of great significance to develop novel,efficient and green treatment methods for practical application.In this study,4-Bromophenol（4-BP）,which is typical halogenated phenol,is the main target pollutant.The p-n heterojunction composite semiconductor catalyst with g-C₃N₄ and BiVO₄ as the main materials was prepared.Then the photocatalyst was loaded on different carriers to construct intimately coupled photocatalysis and biodegradation（ICPB）system.The research results are as follows:The B doped g-C₃N₄/BiVO₄ have been fabricated by depositing n-type BiVO₄ on the surface of p-type B-doped g-C₃N₄.The results revealed that the photocatalytic activity of p-n heterojunction was greatly enhanced compared with n-type BiVO₄ and p-type B-doped g-C₃N₄.B doped g-C₃N₄/BiVO₄ heterostructure showed the best photocatalytic degradation activity,which was 2.3-fold higher than that of BiVO₄.The scanning electron microscope（SEM）,X-ray diffraction analysis and X-ray photoelectron spectroscopy（XPS）data confirmed the formation of monoclinic and tetragonal mixed phase BiVO₄.The formation of mixed phase BiVO₄ was attributed to the high temperature calcination as well as surface energy of B doped g-C₃N₄.B doped g-C₃N₄/BiVO₄ formed a heterojunction between g-C₃N₄ and BiVO₄to suppress the recombination of photogenerated charge carriers.Ultraviolet diffuse reflection and photocatalytic degradation experiments showed that BVCN composite photocatalyst had enhanced light absorption capacity and excellent photocatalytic effect.The BVCN composite photocatalyst was loaded on three different carriers of carbon paper,graphite felt,and polyurethane,and a intimately coupled photocatalysis and biodegradation system was constructed to enhance the treatment of 4-BP simulated wastewater,exploring the influence of different carriers on the ICPB system.The results showed that when polyurethane was used as the carrier,there was a dense biofilm inside the carrier.Under the synergistic effect of photocatalysis and biology,the removal rate of 4-BP reached 100%,which was compared with that of photocatalysis alone,the degradation rate of 4-BP increased by 50%.And compared with carbon paper and graphite felt,the mineralization efficiency of polyurethane system was51.11%after 24 hours of reaction,while the mineralization efficiency of carbon paper and graphite felt were 13.8%and 31.51%,respectively.Compared the Excitation-Emission-Matrix Spectra of the inlet water and the outlet water of the three systems,it could been seen that the polyurethane carrier system degrads 4-BP most thoroughly.In the system with polyurethane as the carrier,the bromophenol-degrading bacteria（Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium and Pseudomonas）and the bioflocculation bacteria Terrimonas were significantly enriched.Finally,the possible degradation mechanism of 4-BP with B-doped g-C₃N₄/BiVO₄coupled biodegradation system was proposed.Compared with single photodegradation and biological treatment,the ICPB system based on B-doped g-C₃N₄/BiVO₄ exhibites excellent adsorption,degradation and mineralization effects on 4-BP,and has excellent performance in the removal of refractory halogenated phenols compounds.更多还原