A laboratory-scale column study comparing organic micropollutant removal and microbial diversity for two soil types

This study investigated sorption and biodegradation behaviour of 20 organic micropollutants (OMPs) in lab-scale columns filled with two types of soil (fed with the same water quality) simulating river bank filtration (RBF) under oxic conditions. Retardation factors and OMP biodegradation rates were similar for the two soils that were characterised by a different cationic exchange capacity, organic matter and sand/silt/clay content. This result was supported by the microbial community composition (richness, evenness) of the two soils that became more similar as a result of feeding both columns with the same water quality. This indicates that microbial community composition and thereby OMP removal in soils is primarily determined by the composition of the aqueous phase (organic matter quantity and quality, nutrients) rather than the soil phase. These results indicate that different RBF sites located along the same river may show similar OMP removal (in case of similar water quality and residence time).

This study shows that the microbial community composition and thus OMP removal is primarily determined by the aqueous phase (water quality) rather than the soil phase.