scholarly journals A Method for Quantifying the Role of Carbonate Acid, Sulfuric Acid and Nitric Acid in Carbonate Weathering After Modifying the Effect of Evaporite in Qingjiang Karst Catchment

2021 ◽  
Author(s):  
Xinhui He ◽  
Hong Zhou ◽  
Junwei Wan ◽  
Heng Zhao ◽  
Shiyi He
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Carbonate Rock ◽  
Carbonic Acid ◽  
Hydrodynamic Condition ◽  
Hydrochemical Modeling ◽  
Carbonate Weathering ◽  
Karst Catchment ◽  
The Impact

Abstract Qingjiang river is the second largest tributary of the Yangtze River in Hubei province, it’s also a typical karst catchment. Eighty-two important groundwater samples were collected during high and low water period of 2019. The results show that: (1) The major hydrochemistry types are Ca+Mg-HCO3 and Ca-HCO3, indicate that carbonate weathering is the main source of groundwater chemistry; (2) The results of inverse hydrochemical modeling show that there are two kinds of groundwater-carbonate rock interactions. One is co-dissolution of calcite and dolomite, the other is dedolomitization, and thereinto, dedolomitization is widespread in dolomite aquifers. Furthermore, gypsum has a tendency to dissolve in each aquifer, and the common ion effect of Ca2+ caused by gypsum dissolution promotes dedolomitization. The modeling results suggest that major elements have a good traceability effect on the material source of groundwater. (3) The chemical weathering of carbonate rock is mainly affected by carbonic acid, sulfuric acid and nitric acid. After modifying the impact of evaporite and atmospheric input, the calculations show that the contribution of carbonic acid involved in carbonate weathering is 70.9% (high water period) and 70.0% (low water period). Through statistics of karst springs discharge and contribution of acid involved in carbonate weathering, the two are in a positive relationship. The result can reflect the laws of sulfuric acid and nitric acid under the hydrodynamic condition in different seasons. Therefore, the carbonate weathering should be carefully evaluated in karst areas which have abundant groundwater and the role of groundwater in carbonate weathering is worthy of further study.

scholarly journals Chemical Weathering and Riverine Carbonate System Driven by Human Activities in a Subtropical Karst Basin, South China

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1524 ◽  
Author(s):  
Xiaoxi Lyu ◽  
Zhen Tao ◽  
Quanzhou Gao ◽  
Haixia Peng ◽  
Mei Zhou
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
South China ◽  
Human Activities ◽  
Chemical Weathering ◽  
Carbonic Acid ◽  
Total Alkalinity ◽  
Karst Water ◽  
Carbonate System ◽  
Co2 Consumption

In the context of climate change, the input of acid substances into rivers, caused by human activities in the process of industrial and agricultural development, has significantly disrupted river systems and has had a profound impact on the carbon cycle. The hydrochemical composition and which main sources of the Lianjiang River (LR), a subtropical karst river in northern Guangdong Province, South China, were analyzed in January 2018. The objective was to explicate the influence on the deficit proportion of CO2 consumption, resulting from carbonate chemical weathering (CCW), driven by nitric acid (HNO3) and sulfuric acid (H2SO4), which is affected by exogenous acids from the industrial regions in north of the Nanling Mountains and the Pearl River Delta. The response of the riverine carbonate system to exogenous acid-related weathering was also discussed. HCO3− and Ca2+, respectively, accounted for 84.97% of the total anions and 78.71% of the total cations in the surface runoff of the LR, which was characterized as typical karst water. CCW was the most important material source of river dissolved loads in the LR, followed by human activities and silicate chemical weathering (SCW). Dissolved inorganic carbon (DIC), derived from CCW induced by carbonic acid (H2CO3), had the largest contribution to the total amount of DIC in the LR (76.79%), and those from CCW induced by anthropogenic acids (HNO3 and H2SO4) and SCW contributed 13.56% and 9.64% to the total DIC, respectively. The deficit proportion of CO2 consumption associated with CCW resulting from sulfuric acid and nitric acid (13.56%), was slightly lower than that of the Guizhou Plateau in rainy and pre-rainy seasons (15.67% and 14.17%, respectively). The deficit percentage of CO2 uptake associated with CCW induced by sulfuric acid and nitric acid, accounted for 38.44% of the total CO2 consumption related to natural CCW and 18.84% of the anthropogenic acids from external areas. DIC derived from CCW induced by human activities, had a significant positive correlation with the total alkalinity, SIc and pCO2 in river water, indicating that the carbonate system of the LR was also driven by exogenous acids, with the exception of carbonic acid. More attention should be paid to the effects of human activities on the chemical weathering and riverine carbonate system in the karst drainage basin.

The role of nitric acid in atmospheric new particle formation

2018 ◽  
Vol 20 (25) ◽  
pp. 17406-17414 ◽  
Author(s):  
Ling Liu ◽  
Hao Li ◽  
Haijie Zhang ◽  
Jie Zhong ◽  
Yang Bai ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Formation Mechanism ◽  
Cluster Formation ◽  
Particle Formation ◽  
New Particle Formation

The cluster formation mechanism indicates that nitric acid can connect the smaller and larger clusters, enhancing sulfuric acid–ammonia cluster formation rates.

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>

scholarly journals Impact of sulfuric acid on carbonate dissolution in the upper-middle reaches of Wujiang River

2019 ◽  
Vol 98 ◽  
pp. 01022
Author(s):  
Qibo Huang ◽  
Xiaoqun Qin ◽  
Liankai Zhang ◽  
Pengyu Liu
Keyword(s):  
Sulfuric Acid ◽  
Surface Water ◽  
Carbonate Rock ◽  
Carbonic Acid ◽  
Anthropogenic Activities ◽  
Anthropogenic Sources ◽  
Rock Weathering ◽  
Carbonate Dissolution ◽  
Wujiang River ◽  
Major Cations

Due to rapid population and economic growth in recent years, the Wujiang River has been heavily impacted by anthropogenic activities. Of particular concern is the increase in SO42- concentration of the river water from various anthropogenic sources. The results showed that the major cations of groundwater and surface water were Ca2+ and Mg2+ (>70% of the cation concentration), and the main anions were HCO3-and SO42-(>85% of the anion concentration). In groundwater, the contributions of carbonate dissolution to Ca2++Mg2+ by sulfuric acid ranged from 20.6% to 92.9% (average 51.5%); and to HCO3- from 11.5% to 86.7% (average 36.9%). In the surface water, the contributions of carbonate dissolution to Ca2++Mg2+ ranged from 56.1% to 94.6% (average 76.9%); and to HCO3from 39.0% to 89.7% (average 64.2%). Our results demonstrate that besides carbonic acid, sulfuric acid also plays an important role on carbonate rock weathering, and influences the hydrochemistry of both groundwater and surface water in the Wujiang River drainage.

Intergroup Threat and Outgroup Attitudes

2013 ◽  
Vol 44 (5) ◽  
pp. 311-319 ◽  
Author(s):  
Marco Brambilla ◽  
David A. Butz
Keyword(s):  
Gay Men ◽  
Social Group ◽  
Welfare Recipients ◽  
Intergroup Attitudes ◽  
Social Policies ◽  
Intergroup Threat ◽  
Economic Threat ◽  
The Impact ◽  
General Climate

Two studies examined the impact of macrolevel symbolic threat on intergroup attitudes. In Study 1 (N = 71), participants exposed to a macrosymbolic threat (vs. nonsymbolic threat and neutral topic) reported less support toward social policies concerning gay men, an outgroup whose stereotypes implies a threat to values, but not toward welfare recipients, a social group whose stereotypes do not imply a threat to values. Study 2 (N = 78) showed that, whereas macrolevel symbolic threat led to less favorable attitudes toward gay men, macroeconomic threat led to less favorable attitudes toward Asians, an outgroup whose stereotypes imply an economic threat. These findings are discussed in terms of their implications for understanding the role of a general climate of threat in shaping intergroup attitudes.

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