煤热解废水典型工艺流程中芳香化合物的降解特性

Aromatic compounds degradation characterization in a typical process of coal pyrolysis wastewater treatment

选取河南某低阶煤热解废水处理典型工艺流程为研究对象,探讨了各单元对芳香化合物的降解特性。通过降解效能对比发现,SBR工艺对酚类(96.13%)和氮杂环类化合物(78.13%)的降解能力最高,故其为芳香化合物降解的核心单元。通过凝胶色谱、紫外-可见光光谱和三维荧光光谱对全流程废水特性的表征,推测出其分子质量在3 kDa左右,荧光峰在Ex/Em=(300~370)nm/(400~450)nm的腐殖酸物质是煤热解废水关键的难生化物质。各单元的统计分析结果表明,废水处理效果不佳的原因在于酸化、气浮、好氧及强氧化单元。在此基础上,根据最新研究结果和成功案例对现有工艺提出了针对性改进方案。以上结果可为类似的废水处理工程提供参考。

A typical process of low-rank coal pyrolysis wastewater treatment in Henan province was investigated for the degradation performance of aromatic compounds in each unit. Through comparison of degradation performance, the SBR process was regarded as the core unit for aromatic compounds degradation since it exhibited the highest removal efficiency on phenols(96.13%) and nitrogen heterocycle compounds(78.13%). Through the wastewater characterization during the entire process by gel chromatography, UV-vis absorption spectra and fluorescence spectrum, humic acid substance with molecular weight at 3 kDa,fluorescence peak at Ex/Em=(300~370) nm/(400~450) nm was inferred as the critical refractory pollutants.Finally, the statistical analysis revealed that acidification, air flotation, aerobic and chemical oxidation units were mainly responsible for the unfavorable performance of the entire process. Moreover, the targeted improvement suggestion was proposed according to the latest research and successful case. The result provides the reference for similar wastewater treatment engineering programs.