Nitrate leaching and its implication for Fe and As mobility in a Southeast Asian aquifer.
Martyna GlodowskaYinxiao MaGarrett SmithAndreas KapplerMike S M JettenCornelia U WeltePublished in: FEMS microbiology ecology (2023)
The drinking water quality in Southeast Asia is at risk due to arsenic (As) groundwater contamination. Intensive use of fertilizers may lead to nitrate (NO3-) leaching into aquifers, yet very little is known about its effect on iron (Fe) and As mobility in water. We ran a set of microcosm experiments using aquifer sediment from Vietnam supplemented with 15NO3- and 13CH4. To assess the effect of nitrate-dependent anaerobic methane oxidation (N-DAMO) we also inoculated the sediment with two different N-DAMO enrichment cultures. We found that native microorganisms and both N-DAMO enrichments could efficiently consume all NO3- in 5 days. However, CH4 oxidation was observed only in the inoculated microcosms, suggesting that the native microbial community did not perform N-DAMO. In uninoculated microcosms, NO3- was preferentially used over Fe(III) as an electron acceptor and consequently inhibited Fe(III) reduction and As mobilization. The addition of N-DAMO enrichment cultures led to Fe(III) reduction and stimulated As and Mn release into the water. The archaeal community in all treatments was dominated by Ca. Methanoperedens while the bacterial community consisted of various denitrifiers. Our results suggest that input of N fertilizers to the aquifer decreases As mobility and that CH4 cannot serve as an electron donor for NO3- reduction.
Keyphrases
- microbial community
- heavy metals
- drinking water
- metal organic framework
- water quality
- risk assessment
- nitric oxide
- health risk
- room temperature
- visible light
- sewage sludge
- health risk assessment
- healthcare
- antibiotic resistance genes
- aqueous solution
- hydrogen peroxide
- electron transfer
- municipal solid waste
- wastewater treatment
- polycyclic aromatic hydrocarbons
- climate change
- anaerobic digestion
- alcohol consumption