Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1021/acsestwater.3c00245
Document accepted manuscript
Title (Primary) Field and laboratory evidence for manganese redox cycling controlling iron and arsenic retention in household sand filters
Author Le, A.V.; Muehe, E.M.; Bone, S.; Drabesch, S.; Fischer, S.; Kappler, A.
Source Titel ACS Environmental Science and Technology Water
Year 2024
Department AME
Volume 4
Issue 1
Page From 33
Page To 43
Language englisch
Topic T7 Bioeconomy
Supplements https://pubs.acs.org/doi/suppl/10.1021/acsestwater.3c00245/suppl_file/ew3c00245_si_001.pdf
Keywords sand filters; biogeochemical processes; Fe; Mn; As
Abstract Application of household sand filters (SFs) is widespread in low-income regions, such as West Bengal, Bangladesh, and Vietnam, for the removal of groundwater contaminants including Fe, Mn, and As. SF operation typically transitions from (oxic) unsaturated conditions to saturated conditions, creating oxygen-limited zones within sand layers. To ensure the safe and effective use of SFs, understanding filter performance and spatiotemporal changes of solid-associated Fe, As, and Mn in different saturation conditions is crucial but remains unknown. Therefore, column experiments were conducted to follow Fe, As, and Mn removal and their distribution and speciation on sand grain surfaces under unsaturated and saturated conditions. On average, 99 ± 0.2, 93 ± 0.7, and 91 ± 8% of Fe(II)aq, As(III)aq, and Mn(II)aq were removed under unsaturated conditions. Under saturated conditions, Fe and As removal remained constant, whereas up to 5 mg/L Mn(II)aq was leached from columns. μXANES analysis showed that solid-associated Fe(III), As(V), and Mn(III)/(IV) dominated in unsaturated sand. However, under saturated conditions, up to 46 and 15% of Fe(III) and As(V) were reduced, and the presence of Mn(II) was confirmed in the anoxic zones. The results suggest that Mn(IV) oxides formed during unsaturated conditions, serving as hosts and oxidants for Fe and As in SFs under reducing conditions.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=29408
Le, A.V., Muehe, E.M., Bone, S., Drabesch, S., Fischer, S., Kappler, A. (2024):
Field and laboratory evidence for manganese redox cycling controlling iron and arsenic retention in household sand filters
ACS ES&T Water 4 (1), 33 - 43 10.1021/acsestwater.3c00245