摘要
甲硫醇是主要恶臭污染物之一,研究甲硫醇的降解技术对于恶臭异味的治理具有重要意义.为了获得臭氧对气体中甲硫醇的氧化降解性能,实验研究了臭氧对气体中甲硫醇的均相氧化过程,考察了氧含量、臭氧投加量、反应时间、温度和湿度等因素的影响.结果表明,氧气可将甲硫醇部分氧化为二甲二硫.甲硫醇去除率随臭氧投加量、反应时间的增加而升高,且臭氧对气体中甲硫醇的氧化降解过程符合伪一级动力学反应模型.甲硫醇的去除率随温度升高而增大,该趋势在温度高于50℃时不再明显;氧化反应的最佳相对湿度为45%-62%.采用原位红外光谱、气相色谱-质谱联用和离子色谱技术对甲硫醇氧化降解过程的研究证明,考察条件下,臭氧不能将全部甲硫醇矿化为二氧化碳和水,而是生成了部分醛类和酮类中间产物,且甲硫醇中硫的主要氧化产物是硫单质.综合考虑臭氧氧化甲硫醇的最佳反应条件和降解产物,该工艺存在能耗高、易造成二次污染等不足,在实际应用中不建议采用臭氧直接氧化工艺对含甲硫醇臭气进行净化.
Methyl mercaptan is one of the main odor pollutants,and the research on degradation of methyl mercaptan is of great significance for the treatment of odor pollution.In this study,the homogeneous ozonation of gaseous methyl mercaptan was studied to obtain the performance of the oxidative degradation of gaseous methyl mercaptan by ozone.The effects of oxygen content,ozone dosage,reaction time,temperature and humidity were investigated.The results showed that oxygen can partially oxidize methyl mercaptan to dimethyl disulfide.The removal of methyl mercaptan increased with the increase of ozone dosage and reaction time,and the oxidative degradation process fitted well with the pseudo first-order kinetic reaction model.Moreover,the removal of methyl mercaptan increased firstly with the increase of temperature,and then tended to a constant value above 50℃.The optimum relative humidity was 45%-62%for the oxidation reaction.Further study by in-situ infrared spectroscopy,gas chromatography-mass spectrometry and ion chromatography showed that under the investigated conditions,ozone cannot mineralize all methyl mercaptan into carbon dioxide and water.Some aldehydes and ketones intermediates were produced,and the main oxidation product of sulfur in methyl mercaptan was elemental sulfur.Considering the optimal reaction conditions of the ozonation of methyl mercaptan and its degradation products,the process has the disadvantages of high energy consumption and potential secondary pollution.In practical application,direct ozonation process is not recommended to purify the odor containing methyl mercaptan.
作者
段文杰
黄伟庆
许欣欣
贾俊俊
田振邦
赵亮
黄做华
王俊
DUAN Wenjie;HUANG Weiqing;XU Xinxin;JIA Junjun;TIAN Zhenbang;ZHAO Liang;HUANG Zuohua;WANG Jun(Institute of Chemistry,Henan Academy of Sciences,Zhengzhou,450003,China)
出处
《环境化学》
CAS
CSCD
北大核心
2023年第8期2630-2639,共10页
Environmental Chemistry
基金
河南省科学院基本科研费项目(220603009,200603110,210603035)
河南省科技攻关项目(212102310523)资助。
关键词
甲硫醇
臭氧
氧化
恶臭气体
methyl mercaptan
ozone
oxidation
odor
