Quantitative and Qualitative Analysis of Organic Halogenated Compounds Unintentionally Generated in Wastewater Treatment Plants using Liquid Chromatography/Mass Spectrometry and High-Resolution Mass Spectrometry

Abstract

Summar yA liquid chromatography/tandem mass spectrometr y (LC/MS/MS) method was developed for simultaneously measuring bisphenol A (BPA), chlorinated BPAs (Cl x BPAs), and brominated BPAs (Br y BPAs) unintentionally generated in wastewater treatment plants (WWTPs). The main purpose of this study was to develop a non-derivatizing measurement method based on LC/MS/MS to analyze BPA, mono-, di-, tri-, and tetra-substituted BPAs by the chlorine or bromine groups in the aromatic rings (11 chemicals in total) via full separation and selective quantitation. In this method, the limit of detection for the chemicals was found to be within 0.01-0.16 µg/L, with recoveries of 50.6-77.9 % and relative standard deviation of 4.3-16 %. We also investigated halogenated BPAs generated by sterilizing the water treated by the WWTP with sodium hypochlorite. BPA and Br4-BPA, which are usually contained in industrial products, are the more abundant BPA congeners before the sterilization process. In one plant that receives a large amount of industrial wastewater, the concentrations of almost all halogenated BPAs decreased after the sterilization process. The concentration of Br4-BPA significantly decreased after the sterilization, while that of Cl4-BPA tended to increase. This suggested that Cl4-BPA was generated from BPA as well as halogenated BPAs (particularly Br4-BPA) during sterilization. Finally, non-targeted analysis using accurate mass measurement with LC/Q-ToFMS also discovered three other chemicals unintentionally generated in the effluents from the sterilization process, such as chlorophenol as a precursor of chlorinated dioxin, which is related to BPA congeners. Chemicals with the elemental compositions of pharmaceuticals were also found.

Short investigation on occurrence and removal of semivolatiles during wastewater treatment processes

“…Other study have shown the presence of 33 pharmaceutical and their 113 by-products in wastewaters from hospitals, from a campus university and from an urban WWTP after fungal treatment with Trametes Versicolor [10]. With the use of sodium hypochlorite as disinfection agent for wastewater streams inadvertently generates new halogenated species, but without known formula [11]. Combining the hybrid membrane aerated biofilm reactor (MABR) system with ozone-biological activated carbon treatment, only 26 of the initial 90 compounds remained in effluent, where butyl trichloroacetate, trichloronitromethane and isopropyl myristate where some of the most refractory compounds [12].…”