水溶液中啶虫脒和对甲酚在树脂上的双组分吸附

研究啶虫脒和对甲酚在单组分、双组分水溶液中在大孔吸附树脂D201和氨基修饰的交联苯乙烯-二乙烯苯共聚体ZH202上不同温度下的吸附行为。实验结果表明,2种吸附剂对单组份两种吸附质的吸附等温线符合Freundlich方程,对甲酚和啶虫脒在2种吸附剂上的吸附过程均属放热的物理吸附过程;双组分吸附体系下,在较高平衡浓度下,呈现协同吸附现象。     

Determination of three cresol isomers in sewage sludge by solid-liquid extraction with low temperature purification and gas chromatography-mass spectrometry

Abstract

Cresols are chemical contaminants derivative from phenol which can be found in sewage sludge. However, little attention has been given to monitoring these compounds in environmental matrices in the literature. Thus, the objective of this study was to develop a simple method based on solid-liquid extraction with low temperature purification for determining three cresol isomers in sludge. The quantification of these compounds was performed by gas chromatography coupled to mass spectrometry with a previous derivatization step. After a detailed study, the cresol recovery was higher than 91%, with relative standard deviation lower than 12% and a limit of quantification of 20?μg kg^?1. Linearity was achieved between 10 and 90?μg L^?1 (R² > 0.98) with the standard solutions prepared in matrix extracts due to the trouble caused by the matrix effect. The proposed method was applied with success for monitoring cresols in sewage sludge samples coming from six different wastewater treatment plants. All samples showed contamination by cresols, mainly p-cresol with values between 32.3 and 516.9?μg kg^?1. The majority of the analyzed samples showed a total sum of the isomers higher than the maximum residue limit established by Brazilian legislation (160?μg kg^?1).