Geochemistry and potential environmental impact of the mine tailings at Rosh Pinah, southern Namibia

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F15%3A00111296" target="_blank" >RIV/00216224:14310/15:00111296 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60460709:41210/15:67440 RIV/00216208:11310/15:10306921 RIV/61989592:15310/15:33153656 RIV/00025798:_____/15:00000186

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S1464343X15000242" target="_blank" >https://www.sciencedirect.com/science/article/pii/S1464343X15000242</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jafrearsci.2015.02.005" target="_blank" >10.1016/j.jafrearsci.2015.02.005</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Geochemistry and potential environmental impact of the mine tailings at Rosh Pinah, southern Namibia

Popis výsledku v původním jazyce

Mine tailings at Rosh Pinah located in semiarid southern Namibia were investigated by the combination of mineralogical methods and leaching using water and simulated gastric solution. They are well-neutralized with leachate pH &gt; 7 and neutralization potential ratios (NPR) up to 4. Neutralization is mainly due to abundant Mn-rich dolomite in the matrix. Concentrations of released contaminants in water leachate follow the order Zn &gt; Pb &gt; Cu &gt; As. Relatively high leached concentrations of Zn and partly also of Pb are caused by their link to relatively soluble carbonates and Mn-oxyhydroxides. In contrast, As is almost immobile by binding into Fe-oxyhydroxides, which are resistant to dissolution. Barium is released by the dissolution of Ba-carbonate (norsethite) and precipitates in sulfate-rich pore water as barite. Dissolved concentrations in neutral mine drainage water collected in the southern pond are low, but when total concentrations including colloidal fraction are taken into account, more than 70% of Zn is in colloidal form. Groundwater upgradient of the mine tailings is of poor quality and there seems to be no negative impact on groundwater downgradient from mine tailings. Contaminant concentrations in simulated gastric leachates are in the order Ba &gt; Pb &gt; Zn &gt; Cu &gt; As with a maximum gastric bioaccessibility of 86.6% for Ba and a minimum of 3.3% for As. These results demonstrate that total contaminant content and toxicity in the solid phase are poor predictors of risk, and therefore mineralogical and bioavailability/bioaccessibility studies are necessary for evaluation of contaminant environmental impact.

Název v anglickém jazyce

Geochemistry and potential environmental impact of the mine tailings at Rosh Pinah, southern Namibia

Popis výsledku anglicky

Mine tailings at Rosh Pinah located in semiarid southern Namibia were investigated by the combination of mineralogical methods and leaching using water and simulated gastric solution. They are well-neutralized with leachate pH &gt; 7 and neutralization potential ratios (NPR) up to 4. Neutralization is mainly due to abundant Mn-rich dolomite in the matrix. Concentrations of released contaminants in water leachate follow the order Zn &gt; Pb &gt; Cu &gt; As. Relatively high leached concentrations of Zn and partly also of Pb are caused by their link to relatively soluble carbonates and Mn-oxyhydroxides. In contrast, As is almost immobile by binding into Fe-oxyhydroxides, which are resistant to dissolution. Barium is released by the dissolution of Ba-carbonate (norsethite) and precipitates in sulfate-rich pore water as barite. Dissolved concentrations in neutral mine drainage water collected in the southern pond are low, but when total concentrations including colloidal fraction are taken into account, more than 70% of Zn is in colloidal form. Groundwater upgradient of the mine tailings is of poor quality and there seems to be no negative impact on groundwater downgradient from mine tailings. Contaminant concentrations in simulated gastric leachates are in the order Ba &gt; Pb &gt; Zn &gt; Cu &gt; As with a maximum gastric bioaccessibility of 86.6% for Ba and a minimum of 3.3% for As. These results demonstrate that total contaminant content and toxicity in the solid phase are poor predictors of risk, and therefore mineralogical and bioavailability/bioaccessibility studies are necessary for evaluation of contaminant environmental impact.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2015

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of African Earth Sciences

ISSN

1464-343X

e-ISSN

1879-1956

Svazek periodika

105

Číslo periodika v rámci svazku

MAY

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

12

Strana od-do

17-28

Kód UT WoS článku

000353737000002

EID výsledku v databázi Scopus

2-s2.0-84924248824