TiO2光催化降解水中苯酚的试验研究

以悬浆态TiO2为光催化剂，在紫外光催化反应器中，进行了苯酚溶液的动态光催化降解性能的研究，考察了TiO2用量、TiO2焙烧温度、溶液pH值以及循环流量对苯酚光催化降解的影响。结果表明，TiO2用量1．0g／L，TiO2焙烧温度450℃，循环流量20L／h，紫外光照反应5h，苯酚去除率为71．2％。     

TiO2薄膜气相光催化氧化低浓度三氯甲烷和三氯乙烯的研究

自行设计了气固相光催化实验系统,以铝材为担载体,TCM和TCE为模拟污染物,在常温、常压下,对辐射光源、气体相对湿度、污染物反应浓度等因素对TCM和TCE的光催化降解反应的影响进行了研究.结果表明,在研究所采用的实验条件下,辐射光源采用254 nm时的降解效率要比采用365 nm时高10%左右;气体相对湿度为40%时光催化降解效率最高;随着污染物反应浓度的增加,TCM的降解效率降低,而TCE的降解效率增加.初步的反应动力学研究结果表明,TCM和TCE在二氧化钛表面的光催化降解反应可采用Langmuir-Hinshelwood动力学方程来表征.     

TiO2光催化剂在污水处理中的应用

在污水处理方面TiO2光催化剂以其独特的氧化活性、光学性能和无机化能力引起了人们极大的关注.对TiO2光催化原理、农药、染料和环境荷尔蒙等有机污染物的分解,提高催化效率的方法以及其实用技术等方面,分别作了综合评述.     

纳米TiO2薄膜在不同陶瓷表面的负载及其光催化性能研究

利用2种不同表面处理的陶瓷作为载体,用溶胶凝胶法在其表面进行了纳米TiO2光催化薄膜的负载.采用X射线衍射法(XRD)、X射线光电子能谱仪(XPS)和扫描电镜(SEM)对薄膜的粒径、横断面及表面组成进行了表征和分析,结果表明,TiO2的平均粒径约为15 nm,釉面陶瓷TiO2薄膜分布均匀,膜厚约为300 nm;无釉陶瓷TiO2薄膜分布不均,膜层不明显;2种载体中的一些基质离子在TiO2薄膜有渗透.苯酚的降解实验表明,以2种不同表面处理的陶瓷为载体的TiO2薄膜对苯酚的降解均符合一级反应动力学,就催化活性而言,TiO2/釉面陶瓷＞TiO2/无釉陶瓷,分析认为基质渗透的Ca2 有降低TiO2光催化活性的作用;该薄膜对实际生产多菌灵废水具有催化降解作用.重复降解实验20次,TiO2/釉面陶瓷和TiO2/无釉陶瓷对苯酚的去除率仅分别降低9%和6%.     

TiO2薄膜光催化降解双酚A的研究

采用sol-gel法制备TiO2薄膜。以该薄膜为催化剂，研究了在H2O2存在的条件下，对内分泌干扰物质双酚A的光催化降解反应。分别讨论了pH值、H2O2的加入量、双酚A的初始浓度以及光照时间对降解反应的影响。结果表明，在pH=4，30mg／L的H2O2中对初始浓度为50mg／L的双酚A溶液光照180min有较好的降解效果。     

用光催化氧化法处理垃圾渗滤液的实验研究

以城市生活垃圾渗滤液作为研究对象 ,采用悬浮态半导体催化剂对渗滤液进行处理试验。研究了ZnO TiO2复合半导体催化剂的催化活性 ,并研究了各种实验条件、影响因素及处理效果。研究表明 ,在一定的试验条件下 ,用ZnO TiO2 复合半导体催化剂处理城市垃圾渗滤液效果较好 ,可作为垃圾渗滤液的深度处理。同时得到光催化氧化法处理渗滤液的最佳试验参数。     

Sr_(10)Bi_6O_(24-y)的制备及其光催化活性研究

以S(rNO3)2和Bi2O3为原料,采用高温固相法在900℃煅烧2h合成了纯度较高、钙钛矿型Sr10Bi6O24-y。使用X射线衍射、扫描电子显微镜和X射线光电子能谱对Sr10Bi6O24-y进行了表征。实验结果表明,Sr10Bi6O24-y光催化具有较强的光催化活性,其降解酸性红G的反应动力学符合一级反应。     

Fabrication Mechanical Properties of Unidirectional Jute/PP Composites Using Jute Yarns by Film Stacking Method

This paper mainly focuses on the fabrication process of long fibre reinforced unidirectional thermoplastic composites made using both natural (untreated) treated jute yarns. Jute yarns were wound in layers onto a metallic frame. Polypropylene films were inserted between these layers and compression moulded to fabricate unidirectional jute/PP composite specimens. Static mechanical properties were evaluated from tensile three point bending tests. Pre- post-failure examination were carried out on the test specimens using optical scanning electron microscopy to analyse the test results and investigate the correlations between their impregnation state, processing conditions, mechanical performances and fracture morphologies. For the unidirectional jute/PP film-stacked composites, the results indicated that the processing condition at the moulding temperature of 160°C and moulding pressure of 2.0 MPa for 15 min was ideally suited to obtain optimized properties. Improved wettability of resin melts due to complete matrix fusion at this processing condition facilitated thorough impregnation with minimum microstructural imperfections (microvoids) being generated. Jute/PP composites that contained treated jute yarns have shown superiority in tensile bending properties. Jute yarns polished or coated with PVA/PP (polyvinyl alcohol/polypropylene) must have contributed positively to fibre/matrix interfacial interactions leading to matrix to fibre effective stress transfer, thereby improving their reinforcing effects. Tensile strength and modulus of PP resin increased by approximately 285% and 388%, respectively, due to 50 wt% reinforcement by natural jute yarns. Further improvements in strength and modulus were achieved by approximately 14% and 10%, respectively, when treated yarns were used . The maximum bending stress modulus of jute/PP composites containing untreated yarns were approximately 190% and 460% higher than those of the virgin PP materials, and bending properties were improved by further 11% and 23%, respectively, due to coating treatments on the yarn surface.