焦化废水生物出水中可溶解性有机物的分子识别

Molecular recognition of dissolved organic matter in bio-treated effluent of coking wastewater

焦化废水中可溶解性有机物成分复杂、难生化降解。为从分子层次揭示焦化废水生物出水中可溶解性有机化合物的组成,首先使用二氯甲烷作为萃取剂,通过液液萃取将河北迁安宏奥工贸焦化厂的焦化废水生物出水分离成有机相和萃余相;对有机相进行四组分分离,根据四组分极性的不同,对极性较弱的饱和分和芳香分采用气相色谱-质谱联用仪(GC/MS)分析,对极性较强的胶质和沥青质采用傅里叶变换离子回旋共振质谱结合电喷雾电离源(ESI FT-ICR MS)分析;对极性强的萃余相用固相萃取法得到SPE洗脱物,并进行ESI FT-ICR MS分析。结果表明:饱和分中共检测到120种化合物,焦化废水经生物处理后的难溶解有机物主要为一些分子质量较大的正构烷烃和链烷烃;芳香分中检测到34种化合物,主要检测到较高含量的醇类、酯类和酚类化合物,其中酚类主要是苯酚的烷基取代物;胶质、沥青质和SPE洗脱物分别检测到N_(x)、N_(1)O_(x)、N_(2)O_(x)、O_(x)和O_(x)S_(1)5类主要碱性有机物和非碱性有机物,胶质和沥青质中的化合物类型分布相似,且沥青质中的化合物更加丰富,SPE洗脱物的化合物类型分布与胶质和沥青质差别较大。根据碳数分布和DBE值,分别得到了主要化合物分子的结构,为焦化废水深度处理工艺的优化和改进提供了理论依据。

The composition of soluble organic compounds in coking wastewater is complex and difficult to be biodegraded.In order to reveal the composition of soluble organic compounds in the biological effluent of coking wastewater from the molecular level,dichloromethane was first used as the extractant to separate the biological effluent of coking wastewater from Hebei Qian’an Hong’ao Industry and Trade Coking Plant into organic phase and raffinate phase through liquid-liquid extraction.The organic phase was separated into four components.According to the different polarity of the four components,the saturated and aromatic components with weak polarity were analyzed by GC/MS,and the resin and asphaltene with strong polarity were analyzed by Fourier transform ion cyclotron resonance mass spectrometry combined with electric spray ionization source(ESI FT-ICR MS).The SPE eluate was obtained from the strongly polar raffinate by solid phase extraction and analyzed by ESI FT-ICR MS.The results showed that one hundred and twenty kinds of compounds were detected in the saturated fraction,and the insoluble organics in the coking wastewater after biological treatment were mainly n-alkanes and alkanes with higher molecular weight.Thirty-four compounds were detected in the aromatic fraction,mainly alcohols,esters and phenols with high content,of which phenols were mainly alkyl substitutes of phenol.The resin,asphaltene and SPE eluate detected five main types of alkaline and non alkaline organics,including N_(x),N_(1)O_(x),N_(2)O_(x),O_(x)and O_(x)S_(1),respectively.The distribution of compound types in resins and asphaltenes was similar,and the compounds in asphaltenes were more abundant.The distribution of compound types in SPE eluates was quite different from those in resins and asphaltenes.According to the carbon number distribution and DBE value,the molecular structures of the main compounds were obtained,which provided a theoretical basis for the optimization and improvement of the coking wastewater advanced treatment process.