腈纶废水溶解性有机物的分级解析及可生化性

采用超滤膜法将腈纶废水中溶解性有机物分离为6个不同相对分子质量组分，分析不同组分的溶解性有机碳、UV₂₅₄、SUVA含量和分布情况，应用紫外吸收光谱、傅里叶变换红外光谱等光谱学分析方法对各组分物质结构进行定性分析，评价各组分的可生化性.结果表明废水中以相对分子质量< 3kDa的有机物为主，占比为（56.75±1.38）%；相对分子质量为3k~10kDa的有机物占比为（25.76±1.40）%；相对分子质量> 10kDa的有机物占比为（17.49±0.98）%，且该组分有机物的芳香度高.不同相对分子质量组分的紫外光谱和红外光谱均呈现相似吸收峰，均存在酰基、羧基、羰基及芳香族化合物和不饱和双键类有机物.各组分可生化性结果表明，废水中相对分子质量> 10kDa有机物是腈纶废水低可生化性的主要原因，可能是造成腈纶废水难以达标排放的根源.研究结果可为该废水处理工艺的开发与优化提供重要的指导.

Classification analysis and biodegradability of dissolved organic matter in acrylic wastewater

The dissolved organic matters of acrylic wastewater were fractionated into six fractions separated by ultra-filtration membrane. The amounts and structural compositions of organic compounds were characterized by dissolved organic carbon (DOC), UV₂₅₄ and specific ultraviolet light absorbance (SUVA); the material structure was qualitatively analyzed by Fourier transform infrared spectrometer (FTIR) and ultraviolet spectrum (UV). The results showed that the fraction of molecular weight less than 3kDa had the largest proportion occupied (56.75±1.38)% in the wastewater, and the molecular weight of 3k~10kDa was occupied (25.76±1.40)%. Interestingly, the fraction of molecular weight more than 10kDa had a high degree of aromatic structure, although it only accounted for 17.49%. The analytical results of UV and FTIR demonstrated that the spectral absorptive characteristics of organic compounds from different fractions were not significantly different.The fractions contained an acyl group, a carboxyl group, a carbonyl group compound and an aromatic compound and an unsaturated double bond type organic substance, respectively. The results of biodegradability indicated that the fraction of molecular weight more than 10kDa was the major reason for the low biodegradability of acrylic wastewater, which is probably the root cause of the difficulty discharge under certain standard. The results of this study provided an important guidance for the development and optimization of acrylic wastewater treatment process.