摘要
通过共沉淀法制备了用于湿式氧化吡虫啉农药废水的Mn/Ce复合催化剂,利用BET比表面积测定和XRD对催化剂进行了表征,研究了焙烧温度对Mn/Ce催化剂活性及稳定性的影响,探讨了湿式催化氧化吡虫啉农药废水的适宜反应温度和氧分压.结果表明,Mn/Ce催化剂晶粒细小,晶粒尺寸小于15nm;适当降低焙烧温度,对减小催化剂晶粒、增加比表面积、提高活性有利,但会使金属溶出量增大、稳定性下降;提高反应温度,湿式催化氧化反应速率加快,而氧分压大于1.6MPa后,反应速率不受氧分压影响;使用该催化剂,在温度190℃、氧分压1.6MPa、进水pH为6.21的条件下经120min处理,COD去除率达93.1%;Mn/Ce复合催化剂对湿式氧化吡虫啉农药废水显示较好的活性和稳定性.
Mn/Ce catalyst was prepared with the co - precipitation method and applied to the treatment of pesticide wastewater of imidacloprid production by catalytic wet air oxidation. The catalyst was characterized by means of BET specific surface area measurement and XRD. The effect of the calcinations temperature on the activity and stability of the catalyst was investigated. The effects of catalytic reaction temperature and partial pressure of oxygen on COD removal efficiency were also studied. The results showed that crystal size of the catalyst is less than 15nm. Specific surface area and the concentration of leached Mn and Ce increased and crystal size decreased when decreasing the calcinations temperature. The activity and stability of the catalyst were also affected by the calcinations temperature. The COD removal efficiency were obviously increased when increasing reaction temperature of catalytic reaction, but almost did not change when partial pressure of oxygen exceeded 1.6 MPa. Using Mn/Ce catalyst,93.1% COD removal efficiency was obtained at the conditions of temperature of 190℃ ,pH of 6.21 and partial pressure of oxygen of 1.6 MPa and treatment time 120min. This result indicated that Mn/Ce catalyst had good activity and stability for treatment pesticide wastewater of imidacloprid production.
出处
《环境科学学报》
CAS
CSCD
北大核心
2007年第3期408-412,共5页
Acta Scientiae Circumstantiae
基金
陕西省教育厅专项基金(No.04JK235)
陕西省自然科学基金(No.2004B28)~~
关键词
湿式催化氧化
Mn/Ce复合催化剂
农药废水
吡虫啉
catalytic wet air oxidation
multiple oxide catalyst of manganese and cerium
pesticide wastewater
imidacloprid
