Unravelling the mechanisms of organic micropollutant removal in bio-electrochemical systems: Insights into sorption, electrochemical degradation, and biodegradation processes.
Sci Total Environ
; 945: 173932, 2024 Oct 01.
Article
en En
| MEDLINE
| ID: mdl-38880133
ABSTRACT
Bio-electrochemical systems (BESs) have recently been proposed as an efficient treatment technology to remove organic micropollutants from water treatment plants. In this study, we aimed to differentiate between sorption, electrochemical transport/degradation, and biodegradation. Using electro-active microorganisms and electrodes, we investigated organic micropollutant removal at environmentally relevant concentrations, clarifying the roles of sorption and electrochemical and biological degradation. The role of anodic biofilms on the removal of 10 relevant organic micropollutants was studied by performing separate sorption experiments on carbon-based electrodes (graphite felt, graphite rod, graphite granules, and granular activated carbon) and electrochemical degradation experiments at two different electrode potentials (-0.3 and 0 V). Granular activated carbon showed the highest sorption of micropollutants; applying a potential to graphite felt electrodes increased organic micropollutant removal. Removal efficiencies >80 % were obtained for all micropollutants at high anode potentials (+0.955 V), indicating that the studied compounds were more susceptible to oxidation than to reduction. All organic micropollutants showed removal when under bio-electrochemical conditions, ranging from low (e.g. metformin, 9.3 %) to exceptionally high removal efficiencies (e.g. sulfamethoxazole, 99.5 %). The lower removal observed under bio-electrochemical conditions when compared to only electrochemical conditions indicated that sorption to the electrode is key to guarantee high electrochemical degradation. The detection of transformation products of chloridazon and metformin indicated that (bio)-electrochemical degradation occurred. This study confirms that BES can treat some organic micropollutants through several mechanisms, which merits further investigation.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Contaminantes Químicos del Agua
/
Biodegradación Ambiental
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Técnicas Electroquímicas
Idioma:
En
Revista:
Sci Total Environ
/
Sci. total environ
/
Science of the total environment
Año:
2024
Tipo del documento:
Article
Pais de publicación:
Países Bajos