侯轶 孙起慧 李友明

摘 要：为研究蒸煮黑液中木质素对污染负荷影响，研究了红松木片化学浆蒸煮黑液的污染特性及特征污染物，通过紫外可见光谱法建立了快速测定液相木质素的分析方法及木质素对COD贡献的工作曲线，探究黑液中木质素对总COD污染负荷的贡献.结果表明蒸煮过程中，黑液中含有较高浓度的溶解态有机物，可生化处理性差，成分复杂，主要有机污染物为酚类和有机酸类物质，其中酚类化合物的相对含量高达84.34%；经测定黑液中木质素浓度为65.7 g·L-1，产生CODcr值高达93 640.86 mg·L-1，占黑液总CODcr含量的51%左右，黑液中木质素对黑液废液污染有较大的贡献.

关键词：黑液；有机污染物；木质素；污染负荷；木质素含量

中图分类号：X793文献标志码：A

Abstract：Pollution feature and characteristic pollutants in black liquor of red pine chemical pulping were studied to reveal the contribution of lignin in black liquor to pollution load. A UV-visible spectrometry method to determine lignin content in black liquor was established， together with the work curve of the contribution of lignin to the COD content， to explore the contribution of lignin to the COD content.It was found in the cooking process that the concentration of dissolved organic compounds in the black liquor was high with poor biodegradability and complex components. The main organic pollutants include phenolic and organic acid compounds， where the phenolic compounds have up to 84.34% relative concentration. Lignin concentration in black liquor is 65.7 g·L-1 with produced CODcr value as high as 93 640.86 mg·L-1，which accounts for about 51% of the total CODcr load in black liquor. The results show that lignin is the main source of pollution load for black liquor in traditional chemical pulping industry.

Key words：black liquor；organic pollutants；lignin；pollution load；lignin concentration

造纸产业是与社会发展和国民经济关系密切的原材料产业，但造纸行业用水量大、污染负荷高.废水排放量约占工业废水总排放量的10%，仅次于化工、钢铁工业，对环境造成极大污染.造纸废水主要来源三部分，其中蒸煮黑液占据90%的污染负荷[1]，传统蒸煮反应历程主要包括脱木质素和部分碳水化合物降解反应，现阶段处理碱法蒸煮黑液的方法主要有碱回收法、化学絮凝法[3]、物理处理技术[4-6]、生物处理技术[7-9]以及多项技术联用法等.碱回收法是碱法蒸煮黑液治理中最成熟的处理方式，但由于受纤维原料、黑液提取工艺和设备等因素影响，黑液提取率一般在80%～98%之间，残留的黑液将随着洗选漂过程进入废水系统，造成……