TY - JOUR
T1 - Inoculation Improves Microbial Manganese Removal during the Start-Up of Rapid Sand Filters
AU - Haukelidsaeter, Signe
AU - Boersma, Alje S.
AU - Behrends, Thilo
AU - Lenstra, Wytze K.
AU - van Helmond, Niels A.G.M.
AU - Piso, Lina
AU - Schoonenberg, Frank
AU - van der Wielen, Paul W.J.J.
AU - van Kessel, Maartje A.H.J.
AU - Lücker, Sebastian
AU - Slomp, Caroline P.
N1 - Publisher Copyright:
© 2025 The Authors. Published by American Chemical Society.
PY - 2025/5/9
Y1 - 2025/5/9
N2 - Long start-up times to achieve manganese removal in rapid sand filters can pose challenges for drinking water companies. This study assessed the start-up dynamics of manganese removal in two full-scale dual-media rapid sand filters treating groundwater containing iron, ammonium, and manganese. After inoculation with 20% biologically active coated sand, ammonium and manganese removal efficiencies of ∼60-70% and ∼30-50% were achieved, respectively. Complete removal of ammonium occurred after ∼8 weeks, but ∼17 and ∼25 weeks were required for manganese removal in the two filters. Full manganese removal, accompanied by manganese oxide formation on new grains, was achieved when ∼50% of the ammonium was removed within the anthracite layer. X-ray spectroscopy of manganese oxides in the mineral coatings indicated a dominance of biologically produced manganese oxide with a structure similar to that of δ-MnO2, suggesting continuous microbial manganese oxidation in inoculated rapid sand filters. Concomitant changes in 16S rRNA gene profiles combined with qPCR and solute profiles suggest a key role for Nitrospira in both nitrification and manganese oxidation. We show that inoculation with biologically active filter medium enhances the efficiency of ammonium and manganese removal during filter start-up, offering a promising improvement strategy for rapid sand filters.
AB - Long start-up times to achieve manganese removal in rapid sand filters can pose challenges for drinking water companies. This study assessed the start-up dynamics of manganese removal in two full-scale dual-media rapid sand filters treating groundwater containing iron, ammonium, and manganese. After inoculation with 20% biologically active coated sand, ammonium and manganese removal efficiencies of ∼60-70% and ∼30-50% were achieved, respectively. Complete removal of ammonium occurred after ∼8 weeks, but ∼17 and ∼25 weeks were required for manganese removal in the two filters. Full manganese removal, accompanied by manganese oxide formation on new grains, was achieved when ∼50% of the ammonium was removed within the anthracite layer. X-ray spectroscopy of manganese oxides in the mineral coatings indicated a dominance of biologically produced manganese oxide with a structure similar to that of δ-MnO2, suggesting continuous microbial manganese oxidation in inoculated rapid sand filters. Concomitant changes in 16S rRNA gene profiles combined with qPCR and solute profiles suggest a key role for Nitrospira in both nitrification and manganese oxidation. We show that inoculation with biologically active filter medium enhances the efficiency of ammonium and manganese removal during filter start-up, offering a promising improvement strategy for rapid sand filters.
KW - drinking water production
KW - filter replacement
KW - microbial manganese oxidation
KW - nitrification
KW - rapid sand filtration
UR - http://www.scopus.com/inward/record.url?scp=105002756168&partnerID=8YFLogxK
U2 - 10.1021/acsestwater.5c00050
DO - 10.1021/acsestwater.5c00050
M3 - Article
AN - SCOPUS:105002756168
SN - 2690-0637
VL - 5
SP - 2479
EP - 2489
JO - ACS ES and T Water
JF - ACS ES and T Water
IS - 5
ER -