| Characterisation of acid mine drainage in a high rainfall mountain environment, New Zealand. | |
| | |
MedLine Citation:
|
PMID: 21669330 Owner: NLM Status: In-Data-Review |
Abstract/OtherAbstract:
|
The Stockton coal mine lies at 700-1100m above sea level in a mountainous orographic precipitation zone on the West Coast of the South Island of New Zealand. Rainfall exceeds 6000mm/year and arrives with frequent flood events that can deliver >200mm/day. Streams vary in discharges by up to two orders of magnitude over a time scale of hours. Pyritic waste rock at the mine interacts chemically with even the most intense rainfall, and almost all runoff is acidic to some degree. In the most intense rain event recorded in this study (>10mm/hour), dilution of acid mine drainage (AMD) occurred and pH rose from 3 to >5 over several hours, with stream discharge at a monitoring point rising from <0.5 to >100cumecs. However, most rain events of similar magnitude are less intense, longer duration, and only raise AMD pH to ~4 with similar high discharges. Results presented here for Stockton confirm that it is the intensity of rain events on the hourly scale, rather than the total amount of rainwater delivered to the site, that governs the amount and composition of AMD generated during flood events. Stream discharge loads of dissolved iron and aluminium range from ~20 to 1000kg/hour. Dissolved sulfate and acidity loads are typically ~500kg/hour but can exceed 20tonnes/hour in rain events. First flush effects observable elsewhere around the world involving peak metal loads following dry periods or seasonal changes are not obvious at Stockton due to the high and variable rainfall environment. Dissolved Fe concentrations may be limited in runoff waters by precipitation of jarosite and schwertmannite, especially when rainfall is sufficiently intense to raise pH to 4 or higher. These minerals are widespread in the exposed waste rock on site. Likewise, precipitation of alunite may occur as pH rises in rain events, but no field evidence for this has been observed. |
| | |
Authors:
|
Hugh Davies; Paul Weber; Phil Lindsay; Dave Craw; James Pope |
Publication Detail:
|
Type: Journal Article |
Journal Detail:
|
Title: The Science of the total environment Volume: 409 ISSN: 1879-1026 ISO Abbreviation: Sci. Total Environ. Publication Date: 2011 Jul |
Date Detail:
|
Created Date: 2011-06-14 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 0330500 Medline TA: Sci Total Environ Country: Netherlands |
Other Details:
|
Languages: eng Pagination: 2971-80 Citation Subset: IM |
Copyright Information:
|
Copyright © 2011 Elsevier B.V. All rights reserved. |
Affiliation:
|
Geology Department, University of Otago, PO Box 56, Dunedin, New Zealand. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: A parameterization of dust concentration (PM(10)) of dust events observed at Erdene in Mongolia usin...
Next Document: Elimination of oxide interferences and determination of ultra-trace silver in soils by ICP-MS with i...