Biogeochemical Processes in Denitrifying Woodchip Bioreactors and their Application in the Mining Industry
This thesis evaluates passive denitrifying woodchip bioreactors (DWBs) for the removal of nitrate (NO3-) in neutral pH mine drainage, where water is passed through a carbon-rich porous matrix (e.g. woodchips) for the reduction of NO3- to nitrogen gas. DWBs have been used for the removal of NO3- from...
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Uppsala universitet, Luft-, vatten- och landskapslära
2019
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ftuppsalauniv:oai:DiVA.org:uu-380386 2023-05-15T17:04:22+02:00 Biogeochemical Processes in Denitrifying Woodchip Bioreactors and their Application in the Mining Industry Biogeokemiska processer i kvävebarriärer med tillämpning inom gruvindustrin Nordström, Albin 2019 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-380386 eng eng Uppsala universitet, Luft-, vatten- och landskapslära Uppsala Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 1790 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-380386 urn:isbn:978-91-513-0617-9 info:eu-repo/semantics/openAccess water treatment mine drainage nitrate nitrous oxide DNRA fermentation syntrophy temperature kväverening gruvvatten nitrat lustgas syntrofi temperatur Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser Vattenbehandling Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2019 ftuppsalauniv 2023-02-23T21:52:14Z This thesis evaluates passive denitrifying woodchip bioreactors (DWBs) for the removal of nitrate (NO3-) in neutral pH mine drainage, where water is passed through a carbon-rich porous matrix (e.g. woodchips) for the reduction of NO3- to nitrogen gas. DWBs have been used for the removal of NO3- from water in various settings and are expected to operate with little maintenance for at least a decade; however, the processes controlling the emission of greenhouse gases and other undesirable by-products, as well as the magnitude and variability in NO3- removal rates and how these develop over time, are not completely understood and were the focus of this thesis. Water treatment in DWBs was investigated in laboratory-scale column tests and in a pilot-scale bioreactor installed at the Kiruna iron ore mine, northern Sweden. Denitrification was the major pathway for NO3- removal in both experimental systems. Incoming NO3- concentrations (up to 30.0 mg N L-1) were removed to below detection limits at temperatures and hydraulic residence times (HRTs) between 5-22°C and ~1.9-2.6 days, respectively, without substantial production of nitrite or ammonium (NH4+). NO3- removal was incomplete in both systems when HRTs decreased to ~1 day, and/or as temperature decreased below 5°C in the pilot-scale bioreactor, under which conditions an increased production of nitrous oxide (N2O) and NH4+ was observed (relative to the NO3- reduced). In the column tests, non-ideal flow was detected and solute transport was described using a dual-porosity model. Stagnant zones not transmitting flow did not participate in NO3- removal and the fraction of immobile water increased with increases in the advection velocity, suggesting that bioreactor performance could be enhanced by emphasizing design with low advection velocities. The study demonstrated that dominating biogeochemical processes varied with time in the pilot-scale bioreactor. There was a decline in organic carbon export and increase in pH and alkalinity that, based on a stoichiometric ... Doctoral or Postdoctoral Thesis Kiruna Northern Sweden Uppsala University: Publications (DiVA) Kiruna |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
water treatment mine drainage nitrate nitrous oxide DNRA fermentation syntrophy temperature kväverening gruvvatten nitrat lustgas syntrofi temperatur Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser Vattenbehandling |
spellingShingle |
water treatment mine drainage nitrate nitrous oxide DNRA fermentation syntrophy temperature kväverening gruvvatten nitrat lustgas syntrofi temperatur Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser Vattenbehandling Nordström, Albin Biogeochemical Processes in Denitrifying Woodchip Bioreactors and their Application in the Mining Industry |
topic_facet |
water treatment mine drainage nitrate nitrous oxide DNRA fermentation syntrophy temperature kväverening gruvvatten nitrat lustgas syntrofi temperatur Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser Vattenbehandling |
description |
This thesis evaluates passive denitrifying woodchip bioreactors (DWBs) for the removal of nitrate (NO3-) in neutral pH mine drainage, where water is passed through a carbon-rich porous matrix (e.g. woodchips) for the reduction of NO3- to nitrogen gas. DWBs have been used for the removal of NO3- from water in various settings and are expected to operate with little maintenance for at least a decade; however, the processes controlling the emission of greenhouse gases and other undesirable by-products, as well as the magnitude and variability in NO3- removal rates and how these develop over time, are not completely understood and were the focus of this thesis. Water treatment in DWBs was investigated in laboratory-scale column tests and in a pilot-scale bioreactor installed at the Kiruna iron ore mine, northern Sweden. Denitrification was the major pathway for NO3- removal in both experimental systems. Incoming NO3- concentrations (up to 30.0 mg N L-1) were removed to below detection limits at temperatures and hydraulic residence times (HRTs) between 5-22°C and ~1.9-2.6 days, respectively, without substantial production of nitrite or ammonium (NH4+). NO3- removal was incomplete in both systems when HRTs decreased to ~1 day, and/or as temperature decreased below 5°C in the pilot-scale bioreactor, under which conditions an increased production of nitrous oxide (N2O) and NH4+ was observed (relative to the NO3- reduced). In the column tests, non-ideal flow was detected and solute transport was described using a dual-porosity model. Stagnant zones not transmitting flow did not participate in NO3- removal and the fraction of immobile water increased with increases in the advection velocity, suggesting that bioreactor performance could be enhanced by emphasizing design with low advection velocities. The study demonstrated that dominating biogeochemical processes varied with time in the pilot-scale bioreactor. There was a decline in organic carbon export and increase in pH and alkalinity that, based on a stoichiometric ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Nordström, Albin |
author_facet |
Nordström, Albin |
author_sort |
Nordström, Albin |
title |
Biogeochemical Processes in Denitrifying Woodchip Bioreactors and their Application in the Mining Industry |
title_short |
Biogeochemical Processes in Denitrifying Woodchip Bioreactors and their Application in the Mining Industry |
title_full |
Biogeochemical Processes in Denitrifying Woodchip Bioreactors and their Application in the Mining Industry |
title_fullStr |
Biogeochemical Processes in Denitrifying Woodchip Bioreactors and their Application in the Mining Industry |
title_full_unstemmed |
Biogeochemical Processes in Denitrifying Woodchip Bioreactors and their Application in the Mining Industry |
title_sort |
biogeochemical processes in denitrifying woodchip bioreactors and their application in the mining industry |
publisher |
Uppsala universitet, Luft-, vatten- och landskapslära |
publishDate |
2019 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-380386 |
geographic |
Kiruna |
geographic_facet |
Kiruna |
genre |
Kiruna Northern Sweden |
genre_facet |
Kiruna Northern Sweden |
op_relation |
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 1790 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-380386 urn:isbn:978-91-513-0617-9 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766058439072546816 |