摘要
为了研制高效稳定的新型催化剂,采用共沉淀方法制备了Mn/Ce/La复合催化剂,用于催化湿式氧化处理苯酚模拟废水,考察了催化剂制备条件和催化反应条件对催化剂性能的影响。以NaOH为沉淀剂,将混合盐沉淀物常温下老化0.5h,378K干燥12h,873K焙烧1h,研磨至粒径为75μm,制得Mn/Ce/La复合催化剂。催化剂最佳配比为n(Mn)∶n(Ce/La)=5∶5(n(Ce)∶n(La)=2∶1),将其用于处理2g/L(COD约4760mg/L)的苯酚模拟废水,离子溶出得到了有效控制,COD的去除率达到98%以上。
The aim of the paper is to obtain a kind of effective and stable catalyst that is capable to heighten the efficiency of high concentration organic sewage treatment in CWAO, along with the effects of some operational conditions in preparing the above said catalyst. For the research purpose, we have made some literature survey over the materials and features concerning the catalyst division and application and found the rare earth catalyst with active components of Mn, Ce and La of great technological value. Next, we have discussed the effects of some conditions, including ratio of the active component, precipitating conditions, aging conditions and calcinating conditions, which may have effects on the catalyst. In addition, we have further evaluated the particular features of some related catalysts by means of X-Ray Diffraction （XRD） and BET Surface Area Analysis. The results indicate that the calcinating temperature can be taken as a key factor to improving the quality of the catalyst. With the increase of calcinating temperature, the catalyst might be sintered, and then the BET surface and pore volume is expected to become smaller. The dissolved metal concentration during the reaction proves to be determined by the reacting temperature. However, the dissolved metal concentration tends to increase quickly with the rise of temperature. In addition, the power of catalyst can also be influenced by the ratio of active component and the type of precipitator. The results of our experiments show that the catalyst can be produced with the following conditions, such as n（Mn） ： n（Ce/La） = 5：5（n（Ce） ： n（La） = 2： 1）, NaOH as precipitator, aging 0.5 h with normal temperature, desiccation 12 h with 378 K, calcinating 1 h with 873 K, skive to 75 μm. And the COD removal efficiency tends to reach as high as 98 % with phenol wastewater concentration kept at 2 g/L （when COD is 4 760 mg/L）, the reactive pressure being 1.0 MPa at the temperature of 373 K. and the reative time being 1 h.
出处
《安全与环境学报》
CAS
CSCD
2008年第2期65-67,共3页
Journal of Safety and Environment
关键词
环境工程
催化湿式氧化
稀土金属
复合氧化物催化剂
environmental engineering
catalytic wet air oxidation
rare-earth metal
mixed oxide catalyst
