Arsenic concentrations and solid phase speciation in soils in the Yellowknife region
Roasting of gold-bearing arsenopyrite (FeAsS) ore at mines around Yellowknife resulted in the release of arsenic trioxide (As2O3) via airborne emissions. Previous studies highlighted a persistent elevated arsenic (As) in local lake sediments and surface waters 50 years after the bulk of these emissi...
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ftqueensuniv:oai:https://qspace.library.queensu.ca:1974/26134 2024-06-02T08:15:52+00:00 Arsenic concentrations and solid phase speciation in soils in the Yellowknife region Maitland, Kirsten Geological Sciences and Geological Engineering Jamieson, Heather 2019-04-26T17:59:27Z application/pdf http://hdl.handle.net/1974/26134 eng eng Canadian theses http://hdl.handle.net/1974/26134 Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada ProQuest PhD and Master's Theses International Dissemination Agreement Intellectual Property Guidelines at Queen's University Copying and Preserving Your Thesis This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. arsenic soil Yellowknife Giant Mine mining mineralogy thesis 2019 ftqueensuniv 2024-05-06T10:47:33Z Roasting of gold-bearing arsenopyrite (FeAsS) ore at mines around Yellowknife resulted in the release of arsenic trioxide (As2O3) via airborne emissions. Previous studies highlighted a persistent elevated arsenic (As) in local lake sediments and surface waters 50 years after the bulk of these emissions were released. The objectives of this research are to: 1) characterize regional concentrations of As in Yellowknife area soils; 2) identify factors that explain regional patterns of distribution; and 3) distinguish between natural and anthropogenic As sources in undisturbed soils. Total element analyses were completed for 125 Public Health Layer (PHL) (top 5 cm of cored soil samples), 43 grab samples and 37 samples taken from greater depths in cores, or down core (DC) samples. Total As concentrations ranged from 1.5 to 4900 mg/kg in PHL samples, 12 to 930 mg/kg in grab samples, and 1.6 to 1200 mg/kg in DC samples. The most significant factors on As concentrations in PHL samples include the distance and direction from former mine roasters, soil depth, and terrain unit. Fifty samples were selected for scanning electron microscopy and automated mineralogy (SEM/AM) to identify the solid species of As present within soil units. Anthropogenic sources of As are characterized by the presence of As2O3 and distinctive As-bearing Fe-oxides derived from roaster stack emissions. The most common As-bearing phases identified in soils throughout the study area included: As-bearing Fe-oxides/Fe-oxide mixes (present in 98% of samples), organic Fe-oxide mixes with As (98% of samples), As2O3 (82%), and As-bearing Mn-oxides (60% of samples). Findings from this thesis suggest that previously estimated background levels for As ranging from 0 to 300 mg/kg are too high; median total As-concentrations decrease from 130 mg/kg to 22.5 mg/kg and finally 8.1 mg/kg for samples collected at distances of 0 – 10 km, 10 – 20 km and 20 – 30 km from the Giant roaster. Additional sampling initiatives need to target soils at further distances to ... Thesis Yellowknife Queen's University, Ontario: QSpace Yellowknife |
institution |
Open Polar |
collection |
Queen's University, Ontario: QSpace |
op_collection_id |
ftqueensuniv |
language |
English |
topic |
arsenic soil Yellowknife Giant Mine mining mineralogy |
spellingShingle |
arsenic soil Yellowknife Giant Mine mining mineralogy Maitland, Kirsten Arsenic concentrations and solid phase speciation in soils in the Yellowknife region |
topic_facet |
arsenic soil Yellowknife Giant Mine mining mineralogy |
description |
Roasting of gold-bearing arsenopyrite (FeAsS) ore at mines around Yellowknife resulted in the release of arsenic trioxide (As2O3) via airborne emissions. Previous studies highlighted a persistent elevated arsenic (As) in local lake sediments and surface waters 50 years after the bulk of these emissions were released. The objectives of this research are to: 1) characterize regional concentrations of As in Yellowknife area soils; 2) identify factors that explain regional patterns of distribution; and 3) distinguish between natural and anthropogenic As sources in undisturbed soils. Total element analyses were completed for 125 Public Health Layer (PHL) (top 5 cm of cored soil samples), 43 grab samples and 37 samples taken from greater depths in cores, or down core (DC) samples. Total As concentrations ranged from 1.5 to 4900 mg/kg in PHL samples, 12 to 930 mg/kg in grab samples, and 1.6 to 1200 mg/kg in DC samples. The most significant factors on As concentrations in PHL samples include the distance and direction from former mine roasters, soil depth, and terrain unit. Fifty samples were selected for scanning electron microscopy and automated mineralogy (SEM/AM) to identify the solid species of As present within soil units. Anthropogenic sources of As are characterized by the presence of As2O3 and distinctive As-bearing Fe-oxides derived from roaster stack emissions. The most common As-bearing phases identified in soils throughout the study area included: As-bearing Fe-oxides/Fe-oxide mixes (present in 98% of samples), organic Fe-oxide mixes with As (98% of samples), As2O3 (82%), and As-bearing Mn-oxides (60% of samples). Findings from this thesis suggest that previously estimated background levels for As ranging from 0 to 300 mg/kg are too high; median total As-concentrations decrease from 130 mg/kg to 22.5 mg/kg and finally 8.1 mg/kg for samples collected at distances of 0 – 10 km, 10 – 20 km and 20 – 30 km from the Giant roaster. Additional sampling initiatives need to target soils at further distances to ... |
author2 |
Geological Sciences and Geological Engineering Jamieson, Heather |
format |
Thesis |
author |
Maitland, Kirsten |
author_facet |
Maitland, Kirsten |
author_sort |
Maitland, Kirsten |
title |
Arsenic concentrations and solid phase speciation in soils in the Yellowknife region |
title_short |
Arsenic concentrations and solid phase speciation in soils in the Yellowknife region |
title_full |
Arsenic concentrations and solid phase speciation in soils in the Yellowknife region |
title_fullStr |
Arsenic concentrations and solid phase speciation in soils in the Yellowknife region |
title_full_unstemmed |
Arsenic concentrations and solid phase speciation in soils in the Yellowknife region |
title_sort |
arsenic concentrations and solid phase speciation in soils in the yellowknife region |
publishDate |
2019 |
url |
http://hdl.handle.net/1974/26134 |
geographic |
Yellowknife |
geographic_facet |
Yellowknife |
genre |
Yellowknife |
genre_facet |
Yellowknife |
op_relation |
Canadian theses http://hdl.handle.net/1974/26134 |
op_rights |
Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada ProQuest PhD and Master's Theses International Dissemination Agreement Intellectual Property Guidelines at Queen's University Copying and Preserving Your Thesis This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
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1800740184452497408 |