scholarly journals Conservative transport of dissolved sulfate across the Rio Madre de Dios floodplain in Peru

Geology ◽  
2021 ◽  
Author(s):  
Emily I. Burt ◽  
Markus Bill ◽  
Mark E. Conrad ◽  
Adan Julian Ccahuana Quispe ◽  
John N. Christensen ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Stable Isotope ◽  
Carbonic Acid ◽  
Isotope Composition ◽  
Sulfide Oxidation ◽  
Pyrite Oxidation ◽  
Sulfide Mineral ◽  
Mineral Weathering ◽  
Primary Role ◽  
Peruvian Andes

Mineral weathering plays a primary role in the geologic carbon cycle. Silicate weathering by carbonic acid consumes CO2 and stabilizes Earth’s climate system. However, when sulfuric acid drives weathering, CO2 can be released to the atmosphere. Recent work has established that sulfuric acid weathering resulting from sulfide mineral oxidation is globally significant and particularly important in rapidly eroding environments. In contrast, if SO42– produced by sulfide oxidation is reduced during continental transit, then CO2 release may be negated. Yet, little is known about how much SO42– reduction takes place in terrestrial environments. We report oxygen and sulfur stable isotope ratios of SO42– in river waters and mass budget calculations, which together suggest that SO42– released from pyrite oxidation in the Peruvian Andes mountains is conservatively exported across ~300 km of the Amazon floodplain. In this system, floodplain SO42– reduction does not counteract the large SO42– flux from Andean pyrite weathering or measurably affect the stable isotope composition of riverine SO42–. These findings support the hypothesis that uplift and erosion of sedimentary rocks drive release of CO2 from the rock reservoir to the atmosphere.

scholarly journals Industrial Heap Bioleaching of Copper Sulfide Ore Started with Only Water Irrigation

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1299
Author(s):  
Yan Jia ◽  
Heyun Sun ◽  
Qiaoyi Tan ◽  
Jingyuan Xu ◽  
Xinliang Feng ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Copper Sulfide ◽  
Pyrite Oxidation ◽  
Sulfide Mineral ◽  
Copper Sulfides ◽  
Sulfide Ore ◽  
Heap Bioleaching ◽  
Exogenous Addition ◽  
Irrigation Solution ◽  
Copper Sulfide Ore

Sulfuric acid solution containing ferric iron is the extractant for industrial heap bioleaching of copper sulfides. To start a heap bioleaching plant, sulfuric acid is usually added to the irrigation solution to maintain adequate acidity (pH 1.0–2.0) for copper dissolution. An industrial practice of heap bioleaching of secondary copper sulfide ore that began with only water irrigation without the addition of sulfuric acid was successfully implemented and introduced in this manuscript. The mineral composition and their behavior related to the production and consumption of sulfuric acid during the bioleaching in heaps was analyzed. This indicated the possibility of self-generating of sulfuric acid in heaps without exogenous addition. After proving by batches of laboratory tests, industrial measures were implemented to promote the sulfide mineral oxidation in heaps throughout the acidifying stages, from a pH of 7.0 to 1.0, thus sulfuric acid and iron was produced especially by pyrite oxidation. After acidifying of the heaps, adapted microbial consortium was inoculated and established in a leaching system. The launch of the bioleaching heap and finally the production expansion were realized without the addition of sulfuric acid, showing great efficiency under low operation costs.

scholarly journals Chemical weathering pathways in the central Himalaya – new constraints from DI14C and δ34S

2020 ◽  
Author(s):  
Maarten Lupker ◽  
Lena Märki ◽  
Guillaume Paris ◽  
Thomas Blattman ◽  
Negar Haghipour ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Carbon Cycle ◽  
Chemical Weathering ◽  
Carbonic Acid ◽  
Dissolved Inorganic Carbon ◽  
Pyrite Oxidation ◽  
Central Himalaya ◽  
Princeton University ◽  
Radiocarbon Data ◽  
The Impact

<p>Chemical weathering at Earth’s surface releases soluble elements from rocks to streams and the oceans, interacting with the global carbon cycle along multiple pathways. The carbon budget of continental erosion is strongly dependent on the nature and relative importance of these pathways [1]. Weathering of silicate minerals with carbonic acid represents a long-term net sink of atmospheric CO<sub>2</sub>. However, chemical weathering by other acids, such as pyrite oxidation-derived sulfuric acid, represents a net CO<sub>2</sub> source to the atmosphere [2]. Constraining the net balance of acids and lithology involved in weathering reactions is therefore paramount to budget the impact of chemical weathering on the carbon cycle. In this contribution, we present preliminary radiocarbon data measured on dissolved inorganic carbon (DI<sup>14</sup>C) from stream and spring waters in the central Himalaya of Nepal. DI<sup>14</sup>C is a promising tracer of the different chemical weathering reaction pathways [3], and DI<sup>14</sup>C values in the central Himalaya span across the natural spectrum. To constrain sulfate sources, measurements of δ<sup>34</sup>S on dissolved sulfate complement this dataset [4], which also shows considerable variability ranging between -15 to +18 ‰. Inverting the dissolved ion composition and their isotopic constraints provide constraints on the proportions of carbonic and sulfuric acid weathering of silicates and carbonates. These results will then be compared with catchment lithological, geomorphological and climatic parameters.</p><p> </p><p>[1] Berner and Berner, 2012 - Princeton University Press  </p><p>[2] Calmels et al., 2007 – Geology 35-11</p><p>[3] Blattmann et al., 2019 – Scientific Reports 9</p><p>[4] Turchyn et al., 2013 – EPSL 374</p>

METAGENOME-ASSEMBLED GENOMES FROM CAVE WALL DEPOSITS PROVIDE NEW INSIGHTS INTO MICROBIAL SULFIDE OXIDATION IN SULFURIC ACID CAVES

2020 ◽  
Author(s):  
Daniel Jones ◽  
◽  
Maurizio Mainiero ◽  
Maurizio Mainiero ◽  
Benjamin T. Auch ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Sulfide Oxidation ◽  
Cave Wall

scholarly journals Chemical and stable isotope composition of surface and groundwater in the surroundings of the Los Humeros Caldera, Puebla, Mexico

2019 ◽  
Vol 98 ◽  
pp. 07013
Author(s):  
Thomas Kretzschmar ◽  
Matteo Lelli ◽  
Ruth Alfaro ◽  
Juan Ignacio Sanchez ◽  
Yann Rene Ramos
Keyword(s):  
Stable Isotope ◽  
Isotope Composition ◽  
Regression Line ◽  
Sustainable Use ◽  
Geothermal Reservoir ◽  
Maximum Temperature ◽  
Stable Isotope Composition ◽  
Local Fracture ◽  
Hydrogeological Model ◽  
Fracture Systems

It is important to develop a regional hydrogeological model to identify possible recharge and discharge areas for a sustainable use of a geothermal reservoir. The Los Humeros geothermal area is situated within five surficial watersheds and coveres an area of more than 15.000 km2. A total of 208 well and spring samples were collected between June 2017 and November 2018. The stable isotope data for this region define a regression line of δDH2O = 8.032·δ18O + 12 and indicate that groundwater is recharged by regional precipitation. At least 39 groundwater wells, with a maximum temperature of 35 °C, show temperatures above the reported mean average surface temperature of 15 °C. Characteristic elements for geothermal reservoir fluids (B, Li, As) are also present in these groundwaters, indicating a possible connection between the reservoir fluid and the local groundwater through local fracture systems. Concentration of B in these hot wells is between 150 and 35000 ppb.

scholarly journals Trophic Relationships and Habitat Preferences of Delphinids from the Southeastern Brazilian Coast Determined by Carbon and Nitrogen Stable Isotope Composition

PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e82205 ◽  
Author(s):  
Tatiana Lemos Bisi ◽  
Paulo Renato Dorneles ◽  
José Lailson-Brito ◽  
Gilles Lepoint ◽  
Alexandre de Freitas Azevedo ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Isotope Composition ◽  
Habitat Preferences ◽  
Trophic Relationships ◽  
Brazilian Coast ◽  
Stable Isotope Composition ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen

Alteration of the carbon and nitrogen stable isotope composition of beef by substitution of grass silage with maize silage

2005 ◽  
Vol 19 (14) ◽  
pp. 1937-1942 ◽  
Author(s):  
Bojlul Bahar ◽  
Frank J. Monahan ◽  
Aidan P. Moloney ◽  
Padraig O'Kiely ◽  
Charlie M. Scrimgeour ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Isotope Composition ◽  
Stable Isotope Composition ◽  
Maize Silage ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen ◽  
Grass Silage
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