Experimental and in silico assessment of fate and effects of the UV filter 2-phenylbenzimidazole 5-sulfonic acid and its phototransformation products in aquatic solutions. (15th March 2020)

• Record Type: Journal Article
• Authors: Westphal, Janin; Kümmerer, Klaus; Olsson, Oliver
• Is Part Of: Water research. Volume 171(2020)
• Publication Date: 2020-03-15
• Subjects: PBSA -- Photolysis -- UV treatment -- Quantitative structure-activity relationship -- Luminescence inhibition; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2019.115393
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Often ingredients of personal care products are present in treated wastewaters, e. g grey water (GW), and are discharged into aquatic systems. Conventional treatment of GW does not fully eliminate micropollutants such as the UV filter substance 2-phenylbenzimidazole-5-sulfonic acid (PBSA). Photolysis has been proposed as an alternative treatment method for other micropollutants, but it is not clear yet whether it can also be used to eliminate PBSA. One goal of this study was to better understand the basic pathways involved in this process. It aimed to identify photo-transformation products (PTPs) by using, in the test conditions, an initial concentration of PBSA higher than those expected in the environment. The photolysis experiments were carried out using Xenon and UV lamps. Under Xenon irradiation only slight primary elimination was found. UV irradiation resulted in almost complete primary elimination of PBSA but not in full mineralization. Four isomeric mono-hydroxylated PTPs were identified by high resolution mass spectrometry (HRMS) which could be confirmed by other studies. A modified luminescent bacteria test (LBT) with Vibrio fischeri was employed to assess acute and chronic toxic effects of the irradiated photolytic mixtures. A strong correlation was found between the kinetics of two of the PTPs and luminescence inhibition indicating bacterial toxicity. Using a set of in silico quantitative structure-activity relationship (QSAR) models, this study also offered new insights concerning the environmental fate and toxicity of the TPs of PBSA as the TPs generated by UV-treatment are more persistent and partly more toxic than PBSA. Graphical abstract: Image 1 Highlights: Identification of four phototransformation products under multiwavelength irradiation. Structure elucidation of these TPs via HRMS. Combined in vitro and in silico assessment of the TPs toxicity. Formation of TPs by UV-treatment of PBSA in aqueous solution leads to higher toxicity to environmental bacteria.