Detection, identification and control of polar iodinated disinfection byproducts in chlor(am)inated secondary wastewater effluents?

Environmental Science: Water Research & Technology Pub Date: 2018-12-06 DOI: 10.1039/C8EW00718G

Abstract

Disinfection of wastewater effluents could generate numerous toxic disinfection byproducts (DBPs) during wastewater reclamation owing to the complexity of their dissolved organic matter. Recently, iodinated disinfection byproducts (I-DBPs) have attracted increasing attention as a result of their higher toxicity than their brominated and chlorinated analogues. In this study, various new polar I-DBPs in chlor(am)inated wastewater effluents were detected with ultra-performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry (UPLC/ESI-tqMS) by setting a precursor ion scan of m/z 126.9. Three new polar I-DBPs were identified as wastewater I-DBPs, including iodoacetic acid, chloroiodoacetic acid and 3,5-diiodo-4-hydroxybenzaldehyde. The remaining new polar I-DBPs were proposed with structures, nine of which were found to be aromatic halogenated DBPs, and six of which were proposed to be in a group because they share closely related m/z values, retention times, and fragmentation pathways. In addition, formation of these new polar I-DBPs with disinfectants and contact times was also studied. Compared with chlorination, chloramination generated more species and higher concentrations of new polar I-DBPs. Furthermore, control of the newly detected polar I-DBPs during chlorination by coagulation, resin adsorption, and combined processes was compared. Resin adsorption showed a higher precursor removal efficiency than coagulation, and thus achieved a better control of these new polar I-DBPs. Coagulation followed by resin adsorption was the most effective compared with single coagulation and single resin adsorption.

Graphical abstract: Detection, identification and control of polar iodinated disinfection byproducts in chlor(am)inated secondary wastewater effluents
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