江苏江阴污水处理厂排水的三维荧光光谱特征

Fluorescence Excitation Emission Matrix Properties of the Effluents From the Wastewater Treatment Plants in Jiangyin City,Jiangsu Province

纺织印染是江苏省江阴市的主要工业行业之一,江阴市许多污水处理厂接收印染废水,其中溶解性有机物是污水处理工艺中的重要去除对象。由于测量快速简便兼具灵敏性和一定选择性,三维荧光光谱被广泛应用于各类水体溶解性有机物的表征中。该研究主要采用三维荧光光谱分析了江阴市主要污水处理厂排水中溶解性有机物的组成特征。结果表明江阴市主要污水处理厂排水单位溶解性有机碳的UV254值为1.42~5.71 L·(mg·m)^(-1),其溶解性有机物的芳香化程度比一般生活污水处理厂排水高。江阴市主要污水处理厂排水的三维荧光光谱普遍存在类蛋白荧光团。生化或者“生化+混凝沉淀”工艺出水单位溶解性有机碳的类蛋白荧光强度大于2.86 R.U.·L·mg^(-1),而强氧化工艺出水单位溶解性有机碳的类蛋白荧光强度低得多,小于0.60 R.U.·L·mg^(-1),这主要是由于强氧化工艺对类蛋白荧光有机物芳香结构的分解作用所致。约33%的污水处理厂排水还存在类腐殖质荧光,腐殖化指数高于其他污水处理厂排水。通过平行因子法分解,江阴污水处理厂排水的三维荧光光谱含有2个类蛋白组分(峰位置分别位于225,280/320 nm和230,285/340 nm)和1个类腐殖质组分(峰位置位于240/415 nm)。江阴市主要污水处理厂排水中的类蛋白荧光团可能主要来源于分散剂MF。分散剂MF是一种常见的商品化染料添加剂,能够显著提升还原染料和分散染料等的分散性能。其主要成分为洗油磺化后的甲醛缩合物,难以生化降解。研究发现有助于深入了解江阴市污水处理厂排水中的有机污染物组成特征,对于处理工艺优化和深度处理工艺研发具有重要的指导意义。

Textile printing and dyeing is one of the major industrial sectors in Jiangyin City,Jiangsu Province and textile wastewater was received by many wastewater treatment plants(WWTPs)in Jiangyin City.Dissolved organic matter(DOM)was the major removal target during the wastewater treatment process.Due to fast and convenient measurement,high sensitivity and moderate selectivity,excitation-emission matrix(EEM)has been extensively used to characterize DOM in various water bodies.In this study,the DOM components of the effluents from the main WWTPs in Jiangyin were investigated by EEM.The SUV254 values of the effluents were 1.42~5.71 L·(mg·m)^(-1),which indicated higher aromaticity than treated municipal wastewater.The effluents generally exhibited two protein-like fluorophores.The protein-like fluorescence intensity per unit of DOC of the effluents from the WWTPs employing biological or“biological+coagulation”process(>2.86 R.U.·L·mg^(-1))was much higher than that of the effluents from the WWTPs with strong oxidation process(<0.60 R.U.·L·mg^(-1)),which was ascribed to the decomposition of aromatic structure of protein-like fluorescent DOM by strong oxidation.The effluents from about 33%of the WWTPs showed humic-like fluorescence with a higher humification index than the effluents from the other WWTPs.Two parallel factor analysis obtained two protein-like components with the peaks at 225,280/320 nm and 230,285/340 nm and one humic-like component with the peak at 240/415 nm.These protein-like fluorophores could be mainly ascribed to Dispersant MF,a kind of common commercial dye additives to improve the dispersion performance of vat and disperse dyes.The main components of Dispersant MF are the formaldehyde condensates of sulfonated washing oil,which are poorly biodegradable.The findings of this work contributed to a profound understanding of the DOM composition in the effluents from the WWTPs in Jiangyin,which was significant to optimization of the treatment process and development of advanced treatment process.