碱解—吹脱联合工艺处理吡虫啉生产废水的研究

发布时间：2018-01-17 22:32

  本文关键词：碱解—吹脱联合工艺处理吡虫啉生产废水的研究　出处：《南京农业大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 吡虫啉 咪唑烷 N N-二甲基甲酰胺 碱解反应 吹脱

【摘要】：我国是农药生产和使用大国,农药行业在我国国民经济中占有重要地位。高效杀虫剂吡虫啉被称为"新烟碱"类化合物,以其高效、低毒、低残留等特点,成为新一代农药的代表。其中最主要的成分是咪唑烷和N,N-二甲基甲酰胺(DMF),导致吡虫啉生产废水含有高浓度的有机氮。因此,如何有效的去除废水中的咪唑烷和DMF成为处理吡虫啉生产废水的关键。本课题研究了模拟废水中咪唑烷和DMF的最佳碱解条件及反应产物;同时对碱解后的模拟废水进行吹脱实验,确定其最佳吹脱条件。通过DMF和咪唑烷的碱解实验,考察了碱解温度、废水pH、碱解时间等因素对咪唑烷和DMF碱解效果的影响。结果表明DMF最佳碱解条件为pH等于13、温度为50℃、碱解时间为2.5小时。DMF的碱解率最高能够达到96.6%,由初始的3800mg/L降低到128.1mg/L。咪唑烷的最佳碱解条件为废水pH等于12、温度为60℃、反应时间为2.5小时。在该条件下,废水中咪唑烷的碱解率达到97.6%,咪唑烷含量由3000mg/L降低到195.5mg/L。通过LC-MS分析发现咪唑烷的碱解产物主要为咪唑烷酮,DMF的碱解产物为二甲胺和甲酸盐。在确定咪唑烷和DMF的最佳碱解条件的基础上综合考虑,选择出吡虫啉生产废水的最佳碱解反应条件:反应温度为60℃、pH为13、反应时间为2.5小时。在此条件下将吡虫啉生产废水进行碱解实验,生产废水中的咪唑烷的碱解率达到96.9%,DMF的碱解率达到95.1%。将碱解后的吡虫啉生产废水进行吹脱实验,通过改变吹脱条件及单因素分析研究pH、温度、气液比等对废水吹脱效果的影响。研究结果表明吡虫啉生产废水碱解后进行吹脱的最佳条件为pH为12.3、吹脱温度为40℃、气液比为3000:1,在此条件下凯氏氮的去除率达到95.7%,由吹脱前的839mg/L降低到36mg/L。吹脱出来的气体可以通过硫酸溶液进行吸收,同时将吸收液进行浓缩,回收产生的铵盐、二甲胺盐等物质。吡虫啉生产废水的吹脱工艺设置在碱解反应之后,可利用碱解反应后的pH值以及残温达到更高的凯氏氮去除效率,降低废水处理的成本。吡虫啉生产废水经碱解吹脱联合工艺处理后的凯氏氮含量为36mg/L,COD为2480mg/L,pH为9.69,经过适当的配水调节后可进行后续生化处理。
[Abstract]:China is a large country in pesticide production and use, and pesticide industry plays an important role in the national economy. Imidacloprid, a highly effective insecticide, is known as a "new nicotine" compound, which is characterized by its high efficiency, low toxicity and low residue. As a representative of a new generation of pesticides, the most important components are imidazolane and N-dimethylformamide (DMFN), which lead to high concentration of organic nitrogen in imidacloprid wastewater. How to effectively remove imidazolane and DMF from wastewater is the key to the treatment of imidacloprid wastewater. In this paper, the optimal alkali hydrolysis conditions and reaction products of imidazolane and DMF in simulated wastewater were studied. At the same time, the simulated wastewater after alkali hydrolysis was blown off, and the optimal blowing conditions were determined. The alkali hydrolysis temperature and pH of wastewater were investigated by DMF and imidazolane alkali hydrolysis experiments. The effect of alkali hydrolysis time on the alkali hydrolysis of imidazolane and DMF was studied. The results showed that the optimum conditions for alkali hydrolysis of DMF were pH = 13 and temperature 50 鈩，

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