Chemical Imaging of Pharmaceuticals in Biofilms for Wastewater Treatment Using Secondary Ion Mass Spectrometry

• Published in: Environmental science & technology Vol. 57; no. 19; pp. 7431 - 7441
• Main Authors: Burzio, Cecilia, Mohammadi, Amir Saeid, Malmberg, Per, Modin, Oskar, Persson, Frank, Wilén, Britt-Marie
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 16.05.2023
• Subjects: Antibiotic resistance; Aquatic environment; Aquatic organisms; biofilm; Biofilms; Biological activity; Biological wastewater treatment; Chemical composition; Citalopram; Citalopram - analysis; Citalopram - pharmacology; Drugs; Ecological effects; Endocrine disruptors; granular sludge; Humans; Hydrologic cycle; Ions; Ketoconazole; Ketoconazole - analysis; Ketoconazole - pharmacology; Lipids; Localization; Mass spectrometry; mass spectrometry imaging; Mass spectroscopy; Occurrence, Fate, and Transport of Aquatic and Terrestrial Contaminants; organic micropollutant; pharmaceutical; Pharmaceutical Preparations; Pharmaceuticals; Phosphocholine; Scientific imaging; Secondary ion mass spectrometry; Sertraline; Sertraline - analysis; Sertraline - pharmacology; SIMS; Spectrometry, Mass, Secondary Ion; Waste Disposal, Fluid - methods; Wastewater; Wastewater treatment; Water Pollutants, Chemical - analysis; Water quality; Water treatment; mass spectrometry imaging; pharmaceutical; wastewater; organic micropollutant; biofilm; SIMS; granular sludge
• ISSN: 0013-936X; 1520-5851; 1520-5851
• DOI: 10.1021/acs.est.2c05027

The occurrence of pharmaceuticals in the aquatic environment is a global water quality challenge for several reasons, such as deleterious effects on ecological and human health, antibiotic resistance development, and endocrine-disrupting effects on aquatic organisms. To optimize their removal from the water cycle, understanding the processes during biological wastewater treatment is crucial. Time-of-flight secondary ion mass spectrometry imaging was successfully applied to investigate and analyze the distribution of pharmaceuticals as well as endogenous molecules in the complex biological matrix of biofilms for wastewater treatment. Several compounds and their localization were identified in the biofilm section, including citalopram, ketoconazole, ketoconazole transformation products, and sertraline. The images revealed the pharmaceuticals gathered in distinct sites of the biofilm matrix. While citalopram penetrated the biofilm deeply, sertraline remained confined in its outer layer. Both pharmaceuticals seemed to mainly colocalize with phosphocholine lipids. Ketoconazole concentrated in small areas with high signal intensity. The approach outlined here presents a powerful strategy for visualizing the chemical composition of biofilms for wastewater treatment and demonstrates its promising utility for elucidating the mechanisms behind pharmaceutical and antimicrobial removal in biological wastewater treatment.