【作者】 兰瑞家；

【导师】 李记太；

【作者基本信息】 河北大学 ， 分析化学， 2013， 博士

【摘要】 高级氧化法是处理有机废水的有效方法,具有良好的开发应用前景。声化学氧化法和光催化氧化技术是高级氧化法中的两个重要组成部分,本论文主要采用这两种方法来处理水体中的有机污染物：超声波技术,在降解有机污染物方面越来越受到人们的关注。在本研究中,以碱性品红作为目标污染物,探讨了功率,温度,溶液初始pH对降解率的影响。并研究了均相催化剂亚铁离子,以及非均相催化剂TiO：对降解效果的影响。发现Fe2+的加入可以较大程度地提高降解效率,而TiO2的促进效果并不明显。自由基捕捉剂的加入导致降解过程被明显地抑制。响应面法是用于建立经典模型的统计学方法,通过实验设计来对响应值进行最优化。采用超声/Fenton试剂联合的方法降解萘普生,通过单因素实验确定了各影响因素的水平范围。又通过中心组合设计试验评价了Fe2+、H2O2浓度以及萘普生浓度三个因素的影响效果(pH=3,超声波功率设定在90%),最后通过响应面分析法优化得到了最高降解率和相应的最佳降解条件。工业用碳纳米管作为一种有效的吸附剂已经成功地应用于去除一些环境污染物。与单独超声和单独用多壁碳纳米管(伴随搅拌)相比,超声和多壁碳纳米管相结合对于酸性橙74的吸附作用更加显著。研究了碳纳米管用量、超声时间、温度、溶液初始浓度和pH值对吸附过程的影响。与Freundlich等温吸附模型相比,Langmuir模型更适合描述酸性橙74在碳纳米管上的吸附行为。通过热力学分析的数据,推测酸性橙74和碳纳米管的吸附类型为物理吸附。动力学分析表明,吸附过程遵循准二级动力学模型。以纳米TiO：为催化剂利用太阳光降解不同类型的染料(阴离子型和阳离子型),探讨了催化剂对不同类型染料的吸附和光催化降解特性。以酸性橙74为研究对象,考察了催化剂Ti02的用量、染料浓度、溶液pH值等因素对光降解的影响。通过对降解产物进行阴离子色谱分析,发现经过光催化降解后酸性橙74并没有完全矿物化。采用水热法制备出了Ti02/石墨烯复合材料。并考察了氧化石墨用量对复合材料光催化性能的影响。实验结果初步证实石墨烯的引入有利于提高TiOz的光催化降解能力。在紫外光照射下,Ti02/石墨烯复合材料催化降解亚甲基蓝水溶液的活性是Ti02的2.5倍。这种降解效率的提高主要是依赖于复合材料中的石墨烯可以传导光照TiOz产生的电子,提高了电子空穴对的分离效率。更多还原

【Abstract】 Advanced Oxidation Processes (AOPs) are emerging as powerful and efficient techniques for the treatment of organic wastewaters. In the present study, ultrasonic technology and photocatalytic oxidation, as the important components of AOPs, were utilized in the degradation of organic pollutants from aqueous solutions.Ultrasonic degradation is proven to be effective for removing organic pollutants from aqueous solutions. In this study, removal of fuchsin basic from aqueous solutions by ultrasound was investigated. The effects of operating parameters such as ultrasound power, initial pH and temperature on the ultrasonic degradation were studied. Addition of catalyst Fe2+had a markedly positive effect on degradation. But addition of heterogeneous catalyst TiO2affected degradation slightly. Addition of radical scavenger suppressed fuchsin basic degradation significantly.Response surface methodology (RSM) is a collection of mathematical and statistical techniques for empirical model building. By design of experiments, the objective is to optimize a response which is influenced by several independent variables. Degradation of naproxen by combination of Fenton reagent and ultrasound irradiation was investigated and experiment conditions were optimized by using response surface methodology. Some preliminary runs were performed with the purpose of establish the variable ranges. After that, a central composite design was applied to evaluate the effect of H2O2, Fe2+and NPX concentration after10min, at pH=3and ultrasonic power amplitude at90%. Optimization by the response surface methodology was utilized to obtain the optimum of concentration of H2O2, Fe2+and NPX that resulted in the highest response.Industrial carbon nanotubes have been successfully applied in adsorption of environmental pollutants. The adsorption behaviour of Acid orange74(AO74) from aqueous solution by the combination of ultrasound and multi-walled carbon nanotubes (MWCNTs) was investigated. The combination method of ultrasound and MWCNTs achieved better results than either MWCNTs or ultrasound alone. The effects of dosage of MWCNTs, ultrasound time, temperature, initial concentration and pH of AO74solution were studied. Experimental isotherm data was represented with Langmuir and Frendlich adsorption isotherms models. The adsorption data were found to follow the Langmuir model better than the Frendlich model. Thermodynamics analysis suggested that adsorption of AO74onto MWCNTs was driven by a physisorption process. The adsorption of AO74follows pseudo second-order kinetics.Researches of sunlight degradation of different types of dyes (anionic and cationic), catalyzed by nanometer TiO2catalyst were did. The adsorptive and catalytic characteristics of different TiO2catalysts were investigated. Acid orange74was chosen as the object substrate to investigate the effects of dosage of the catalyst, dye concentration and initial pH value of the solution. The degradation products were analyzed by anion chromatography and it was found thatacid orange74has not been completely mineralized by photocatalytic oxidation.TiO2/graphene composites were synthesized by hydrothermol method. Influence of dosage of grapheme oxide on the photocatalytic activity of TiO2/graphene was studied. The results showed that the TiO2/Graphene composite exhibited a higher (nearly2.5times) degradation activity than pure TiO2. The enhancement of the photocatalytic activity could be attributed to the excellent electronic conductivity of graphene, which results in that the photogenerated electrons can transport to the surface of the composites more easily, thus inhibiting the recombination between photo-induced electrons and holes.更多还原