Hydraulic and biotic impacts on neutralisation of high-pH waters
The management of alkaline (pH 11–12.5) leachate is an important issue associated with the conditioning, afteruse or disposal of steel slags. Passive in-gassing of atmospheric CO2 is a low cost option for reducing Ca(OH)2 alkalinity, as Ca(OH)2 is neutralised by carbonic acid to produce CaCO3. The r...
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ftunivhullir:oai:hull-repository.worktribe.com:455875 2024-09-15T18:01:39+00:00 Hydraulic and biotic impacts on neutralisation of high-pH waters Gomes, Helena I. Mayes, William M. Rogerson, Mike Burke, Ian T. Stewart, Douglas I. 2017-12-01 https://hull-repository.worktribe.com/file/455875/1/Published%20article https://hull-repository.worktribe.com/output/455875 https://doi.org/10.1016/j.scitotenv.2017.05.248 English eng Elsevier https://hull-repository.worktribe.com/output/455875 Science of the total environment Volume 601-602 Pagination 1271-1279 doi:https://doi.org/10.1016/j.scitotenv.2017.05.248 https://hull-repository.worktribe.com/file/455875/1/Published%20article 0048-9697 doi:10.1016/j.scitotenv.2017.05.248 openAccess Alkaline drainage Biofilm Mesocosm Neutralisation Passive treatment Journal Article acceptedVersion 2017 ftunivhullir https://doi.org/10.1016/j.scitotenv.2017.05.248 2024-07-22T14:05:21Z The management of alkaline (pH 11–12.5) leachate is an important issue associated with the conditioning, afteruse or disposal of steel slags. Passive in-gassing of atmospheric CO2 is a low cost option for reducing Ca(OH)2 alkalinity, as Ca(OH)2 is neutralised by carbonic acid to produce CaCO3. The relative effectiveness of such treatment can be affected by both the system geometry (i.e. stepped cascades versus settlement ponds) and biological colonization. Sterilized mesocosm experiments run over periods of 20 days showed that, due to more water mixing and enhanced CO2 dissolution at the weirs, the cascade systems (pH 11.2→9.6) are more effective than settlement ponds (pH 11.2 → 11.0) for lowering leachate alkalinity in all the tested conditions. The presence of an active microbial biofilm resulted in significantly more pH reduction in ponds (pH 11.2→9.5), but had a small impact on the cascade systems (pH 11.2→9.4). The pH variation in biofilm colonized systems shows a diurnal cycle of 1 to 1.5 pH units due to CO2 uptake and release associated with respiration and photosynthesis. The results demonstrate that, where gradient permits, aeration via stepped cascades are the best option for neutralisation of steel slag leachates, and where feasible, the development of biofilm communities can also help reduce alkalinity. Article in Journal/Newspaper Carbonic acid University of Hull: Repository@Hull Science of The Total Environment 601-602 1271 1279 |
institution |
Open Polar |
collection |
University of Hull: Repository@Hull |
op_collection_id |
ftunivhullir |
language |
English |
topic |
Alkaline drainage Biofilm Mesocosm Neutralisation Passive treatment |
spellingShingle |
Alkaline drainage Biofilm Mesocosm Neutralisation Passive treatment Gomes, Helena I. Mayes, William M. Rogerson, Mike Burke, Ian T. Stewart, Douglas I. Hydraulic and biotic impacts on neutralisation of high-pH waters |
topic_facet |
Alkaline drainage Biofilm Mesocosm Neutralisation Passive treatment |
description |
The management of alkaline (pH 11–12.5) leachate is an important issue associated with the conditioning, afteruse or disposal of steel slags. Passive in-gassing of atmospheric CO2 is a low cost option for reducing Ca(OH)2 alkalinity, as Ca(OH)2 is neutralised by carbonic acid to produce CaCO3. The relative effectiveness of such treatment can be affected by both the system geometry (i.e. stepped cascades versus settlement ponds) and biological colonization. Sterilized mesocosm experiments run over periods of 20 days showed that, due to more water mixing and enhanced CO2 dissolution at the weirs, the cascade systems (pH 11.2→9.6) are more effective than settlement ponds (pH 11.2 → 11.0) for lowering leachate alkalinity in all the tested conditions. The presence of an active microbial biofilm resulted in significantly more pH reduction in ponds (pH 11.2→9.5), but had a small impact on the cascade systems (pH 11.2→9.4). The pH variation in biofilm colonized systems shows a diurnal cycle of 1 to 1.5 pH units due to CO2 uptake and release associated with respiration and photosynthesis. The results demonstrate that, where gradient permits, aeration via stepped cascades are the best option for neutralisation of steel slag leachates, and where feasible, the development of biofilm communities can also help reduce alkalinity. |
format |
Article in Journal/Newspaper |
author |
Gomes, Helena I. Mayes, William M. Rogerson, Mike Burke, Ian T. Stewart, Douglas I. |
author_facet |
Gomes, Helena I. Mayes, William M. Rogerson, Mike Burke, Ian T. Stewart, Douglas I. |
author_sort |
Gomes, Helena I. |
title |
Hydraulic and biotic impacts on neutralisation of high-pH waters |
title_short |
Hydraulic and biotic impacts on neutralisation of high-pH waters |
title_full |
Hydraulic and biotic impacts on neutralisation of high-pH waters |
title_fullStr |
Hydraulic and biotic impacts on neutralisation of high-pH waters |
title_full_unstemmed |
Hydraulic and biotic impacts on neutralisation of high-pH waters |
title_sort |
hydraulic and biotic impacts on neutralisation of high-ph waters |
publisher |
Elsevier |
publishDate |
2017 |
url |
https://hull-repository.worktribe.com/file/455875/1/Published%20article https://hull-repository.worktribe.com/output/455875 https://doi.org/10.1016/j.scitotenv.2017.05.248 |
genre |
Carbonic acid |
genre_facet |
Carbonic acid |
op_relation |
https://hull-repository.worktribe.com/output/455875 Science of the total environment Volume 601-602 Pagination 1271-1279 doi:https://doi.org/10.1016/j.scitotenv.2017.05.248 https://hull-repository.worktribe.com/file/455875/1/Published%20article 0048-9697 doi:10.1016/j.scitotenv.2017.05.248 |
op_rights |
openAccess |
op_doi |
https://doi.org/10.1016/j.scitotenv.2017.05.248 |
container_title |
Science of The Total Environment |
container_volume |
601-602 |
container_start_page |
1271 |
op_container_end_page |
1279 |
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1810438756488970240 |