湿式过氧化氢氧化法处理吡虫啉农药废水研究

Study on treating pesticide sewage from imidacloprid production through wet hydrogen peroxide oxidation

为优化反应条件,在2L压力反应器内,对吡虫啉农药废水进行湿式过氧化氢氧化(WPO)和催化湿式过氧化氢氧化(CWPO)降解处理,考察了过氧化氢加入量、反应温度、进水pH值和催化剂等对反应过程与污染物降解的影响规律。结果表明,WPO和CWPO能在温和的条件下降解难于生物降解的吡虫啉农药废水。温度为110℃,压力为0.6MPa,过氧化氢用量为理论用量,进水pH值为3.5的条件下,WPO处理吡虫啉农药废水,COD去除率为47.7%;采用非均相Cu-Ni-Ce/SiO2催化剂,pH值为7.0,其他条件相同时,CWPO对相同吡虫啉农药废水的COD去除率可达89.1%。计算得CWPO和WPO基于COD的第1阶段表观活化能分别为11.2kJ/mol和29.6kJ/mol。湿式过氧化氢氧化法为农药废水的处理提供了一种经济有效的方法。

The present paper is related to the treatment of sewage left over from imidaeloprid production through wet peroxide oxidation （WPO）. It has also studied the catalytic wet peroxide oxidation （CWPO） in a 2 L autoclave for optimizing the reaction conditions. Further experiments and investigations have also been done so as to gain detailed data and information on the effects of dosage of hydrogen peroxide, the reaction temperature, pH in influent and catalyst on the oxidation process as well as the degradation efficiency. The results of our study show that the organic contamination in the sewage can be degraded to WPO and CWPO, which tend to be stable in structure at lower pressure and temperature compared with the traditional wet air oxidation. At the same time, the COD removal efficiency could reach 47.70% in WPO under the conditions of 110 ℃, 0.6 MPa, initial pH = 3.5 and theoretical peroxide dosage. However, the COD removal efficiency can only be improved to some extent with the increase of temperature and rising of the peroxide dosage. However, if Cu-Ni-Ce/SiO2 catalyst is introduced into the CWPO process, COD removal can be expected to reach 89.1% with pH = 7.0 and the other reaction conditions unchanged. Calculation can also indicate that the activating energy of CWPO in this case tends to decrease by 62.2% as compared with WPO. Therefore, the results of the present research and investigation, WPO and CWPO prove to be a highly economical and efficient approach to the pesticide sewage disposal.