印染及染料行业废水生物处理系统中的AOX污染研究

在印染和染料行业发达的长三角地区选取了6家大型印染企业和4家大型染料生产企业,研究了废水和生物处理污泥中AOX的污染水平,并使用气相色谱质谱分析了AOX的物质结构特征.结果表明,6家印染企业的废水原水AOX质量浓度较低,为0.15~1.62 mg·L-1,处理出水AOX质量浓度为0.06~1.30 mg·L-1,满足《纺织染整工业水污染物排放标准》的特别排放限值8 mg·L-1;活性污泥中AOX含量一般都低于621 mg·kg-1,但个别企业含量很高,达到3 280 mg·kg-1.染料生产企业废水原水的AOX质量浓度差异较大,为1.70~78.72 mg·L-1,出水AOX质量浓度为1.88~33.11 mg·L-1,远高于印染企业出水;污泥中AOX含量也普遍较高,为960~2 297 mg·kg-1.染料废水中的有机卤代物主要包括氯苯类、氯硝基苯类、氯苯胺类、氯硝基苯胺类及卤代苯酚类物质.卤代苯酚类和氯硝基苯胺类较易被生物去除;单氯苯胺、单氯硝基苯类比多氯苯胺、氯硝基苯类易被生物去除;而多氯苯类物质较易被生物去除从而产生较难生物去除的氯苯.

AOX Pollution in Wastewater Treatment Process of Dyeing and Dyestuff Chemical Industries

Selecting six large-scale dyeing factories and four large-scale dyestuff chemical factories in the well-developed Yangtze River Delta region, this study aimed to investigate the AOX pollution status in the raw wastewater as well as in the activated sludge treatment system. The components of AOX were characterized by GC-MS. Results showed that AOX concentration was low in wastewater from the six dyeing enterprises, ranging 0.15-1.62 mg ·L^-1 in the raw wastewater and 0.06-1.30 mg ·L^-1 in the biologically treated effluent. All the biologically treated effluent met the emission limits of 8 mg ·L^-1 in the Discharge Standard of Water Pollutants for Dyeing and Finishing of Textile Industry. Sludge in five factories with AOX was below 621 mg ·kg^-1, only one factory was with high AOX concentration of 3280 mg ·kg^-1. By comparison, AOX concentration greatly varied between the wastewater from dyestuff chemical factories, was 1.70 mg ·L^-1 to 78.72 mg ·L^-1 in the raw wastewater and was 1.88 mg ·L^-1 to 33.11 mg ·L^-1 in the biologically treated effluent. AOX concentration in the activated sludge was as high as 960-2297 mg ·kg^-1. Chlorobenzenes, chloronitrobenzenes, chloroanilines, chlorine nitroanilines and halophenols were typical TOX components detectable in the dyestuff chemical wastewater. Halophenols and chlorine nitroanilines could be efficiently removed. Single chloroanilines and single chloronitrobenzenes seemed to be easier removable than polychlorinated anilines and polychlorinated nitrobenzenes. Polychlorinated benzenes were also easily removal but the products chlorobenzene was hard to remove.