@article{fdi:010064764,
  title = {{H}igh methylmercury production under ferruginous conditions in sediments impacted by sewage treatment plant discharges},
  author = {{B}ravo, {A}. {G}. and {B}ouchet, {S}. and {G}u{\'e}dron, {S}t{\'e}phane and {A}mouroux, {D}. and {D}ominik, {J}. and {Z}opfi, {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{S}ewage treatment plants ({STP}s) are important point sources of mercury ({H}g) to the environment. {STP}s are also significant sources of iron when hydrated ferric oxide ({HFO}) is used as a dephosphatation agent during water purification. {I}n this study, we combined geochemical and microbiological characterization with {H}g speciation and sediment amendments to evaluate the impact of {STP}'s effluents on monomethylmercury ({MMH}g) production. {T}he highest in-situ {H}g methylation was found close to the discharge pipe in subsurface sediments enriched with {H}g, organic matter, and iron. {T}here, ferruginous conditions were prevailing with high concentrations of dissolved {F}e2+ and virtually no free sulfide in the porewater. {S}ediment incubations demonstrated that the high {MMH}g production close to the discharge was controlled by low demethylation yields. {I}nhibition of dissimilatory sulfate reduction with molybdate led to increased iron reduction rates and {H}g-methylation, suggesting that sulfate-reducing bacteria ({SRB}) may not have been the main {H}g methylators under these conditions. {H}owever, {H}g methylation in sediments amended with amorphous {F}e({III})-oxides was only slightly higher than control conditions. {T}hus, in addition to iron-reducing bacteria, other non-{SRB} most likely contributed to {H}g methylation. {O}verall, this study highlights that sediments impacted by {STP} discharges can become local hot-spots for {H}g methylation due to the combined inputs of i) {H}g, ii) organic matter, which fuels bacterial activities and iii) iron, which keeps porewater sulfide concentration low and hence {H}g bioavailable.},
  keywords = {{M}ethylmercury ; {I}ron-reducing bacteria ; {S}ulfate-reducing bacteria ; {S}ediments ; {I}ron ; {S}ewage treatment plant ; {SUISSE} ; {GENEVE} {LAC}},
  booktitle = {},
  journal = {{W}ater {R}esearch},
  volume = {80},
  numero = {},
  pages = {245--255},
  ISSN = {0043-1354},
  year = {2015},
  DOI = {10.1016/j.watres.2015.04.039},
  URL = {https://www.documentation.ird.fr/hor/fdi:010064764},
}