Doris van Halem

This study shows that mild aeration in sand filters promotes biological iron removal, achieving faster oxidation rates and higher water yields compared to intensive aeration.

This study identifies Fe3+ flocs as the main cause of nitrification delay in groundwater filters by inhibiting NH4+ oxidation, showing the inhibition is reversible through backwashing.

The paper identifies a new nitrate-reducing iron-oxidizing bacterium in groundwater, demonstrating its lithoautotrophic growth and metabolic pathway.