Water geochemistry of rivers draining karst-dominated regions, Guangxi province, South China: Implications for chemical weathering and role of sulfuric acid

2018 ◽  
Vol 163 ◽  
pp. 152-162 ◽  
Author(s):  
Hao Jiang ◽  
Wenjing Liu ◽  
Tong Zhao ◽  
Huiguo Sun ◽  
Zhifang Xu
Keyword(s):  
Sulfuric Acid ◽  
South China ◽  
Chemical Weathering ◽  
Guangxi Province ◽  
Water Geochemistry

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 structural reactivation for gold mineralization in northeastern Hunan Province, South China

2021 ◽  
pp. 104306
Author(s):  
Yueqiang Zhou ◽  
Deru Xu ◽  
Guojun Dong ◽  
Guoxiang Chi ◽  
Teng Deng ◽  
...  
Keyword(s):  
South China ◽  
Gold Mineralization ◽  
Hunan Province

scholarly journals Assess the Effectiveness of protective Concrete coatings of microbiological sulfuric acid Aggression

2019 ◽  
Vol 97 ◽  
pp. 02022
Author(s):  
Viktor Sopov ◽  
Julia Danchenko ◽  
Ekaterina Latorez
Keyword(s):  
Sulfuric Acid ◽  
Building Structures ◽  
Predominant Role ◽  
Microbiological Processes ◽  
Repair Materials ◽  
Bactericidal Properties ◽  
Mineral Acids ◽  
Concrete Building ◽  
Modified Epoxy

Specification of corrosion processes in sewerage networks, the predominant role of microbiological processes in them requires the protection of concrete with materials resistant to specific biogenic sulfuric acid aggression. The effective protective materials, in this case, are those that, in addition to acid-proofing materials, have bactericidal properties. Polymer composite materials (PCM) of cold curing based on modified epoxy-resin, resins with dispersed oxides as fillers are widely used in construction. Unique properties and simple technologies make it possible to use them as injection formulations for repair, restoration and restoration of building structures and structures, waterproofing and facing materials, for impregnating, gluing and coating metal, wooden, brick and concrete building structures and parts. In the reconstruction and restoration of sewerage collectors operating under conditions of exposure to liquid biochemically aggressive media with mineral acids and organic substances, particular attention is paid to the permeability of repair materials. Based on the results of the study, PCM compositions were chosen whose estimated lifetime is about 20 years, ensuring reliable protection of the sewage collectors from corrosion.

scholarly journals The role of ammonia in sulfuric acid ion induced nucleation

2008 ◽  
Vol 8 (11) ◽  
pp. 2859-2867 ◽  
Author(s):  
I. K. Ortega ◽  
T. Kurtén ◽  
H. Vehkamäki ◽  
M. Kulmala
Keyword(s):  
Sulfuric Acid ◽  
Quantum Chemical ◽  
Local Minimum ◽  
Good Accuracy ◽  
Energy Surface ◽  
Ground Level ◽  
Computational Effort ◽  
Free Energy Surface ◽  
Large Clusters

Abstract. We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good accuracy-to-computational effort ratio. We have applied this strategy to evaluate the relevance of ternary ion induced nucleation; we have also performed calculations for neutral ternary nucleation for comparison. The results for neutral ternary nucleation agree with previous results, and confirm the important role of ammonia in enhancing the growth of sulfuric acid clusters. On the other hand, we have found that ammonia does not enhance the growth of ionic sulfuric acid clusters. The results also confirm that ion-induced nucleation is a barrierless process at high altitudes, but at ground level there exists a barrier due to the presence of a local minimum on the free energy surface.

Anti-Aging Effect of Siraitia grosuenorii by Enhancement of Hematopoietic Stem Cell Function

2016 ◽  
Vol 44 (04) ◽  
pp. 803-815 ◽  
Author(s):  
Lin Bai ◽  
Guiying Shi ◽  
Yajun Yang ◽  
Wei Chen ◽  
Lianfeng Zhang
Keyword(s):  
Aging Process ◽  
Cell Function ◽  
Whooping Cough ◽  
Aging Effect ◽  
Guangxi Province ◽  
Facs Analysis ◽  
Hematopoietic Stem ◽  
Associated Proteins

Anti-aging has always been a popular topic, and there are many claims about the existence of factors that can slow, stop, or even reverse the aging process. Siraitia grosuenorii, a local fruit in china, has been used for the treatment of gastritis, sore throats, and whooping cough in traditional Chinese medicine. The individuals who took the juice of Siraitia grosuenorii regularly had increased longevity in the Guangxi Province, which is located in the Southern part of China. In this paper, we fed mice with Siraitia grosuenorii for 10 months to identify the role of Siraitia grosuenorii in anti-aging and to investigate its corresponding mechanism. The results showed that mice fed with Siraitia grosuenorii displayed a slower aging process. The extension of the aging process was due to the enhanced function of HSCs. FACS analysis showed that the number of LSKs, LT-HSCs, ST-HSCs and MPPs from Siraitia grosuenorii mice was decreased. In vitro, a clonigenic assay showed that LT-HSCs from Siraitia grosuenorii mice increased the ability of self-renewal. Moreover, Siraitia grosuenorii mice maintained the quiescence of LSKs, decreased the level of ROS and reduced the amount of senescence associated β-gal positive cells. Furthermore, Siraitia grosuenorii mice decreased the expression of senescence-associated proteins. Siraitia grosuenorii maintained quiescence, decreased senescence and enhanced the function of HSCs, slowing the aging process of mice.

The role of acidity profile in the nanotubular growth of polyaniline

2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Elena Konyushenko ◽  
Miroslava Trchová ◽  
Jaroslav Stejskal ◽  
Irina Sapurina
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Reaction Temperature ◽  
Subsequent Growth ◽  
Subsequent Oxidation ◽  
Ammonium Peroxydisulfate ◽  
Aniline Oligomers ◽  
Positive Effect ◽  
Granular Morphology

AbstractConditions of polyaniline (PANI) nanotubes preparation were analyzed. Aniline was oxidized with ammonium peroxydisulfate in 0.4 M acetic acid. There are two subsequent oxidation steps and the products were collected after each of them. At pH > 3, neutral aniline molecules are oxidized to non-conducting aniline oligomers. These produce templates for the subsequent growth of PANI nanotubes, which takes place preferably at pH 2–3. At pH < 2, granular morphology of the conducting PANI is obtained. High final acidity of the medium should be avoided in the preparation of nanotubes, e.g., by reducing the amount of sulfuric acid which is a by-product. Reduction of the peroxydisulfate-to-aniline mole ratio was tested for this purpose in the present study. Lowering of the reaction temperature from 20°C to −4°C had a positive effect on the formation of nanotubes.

The Role of Binary and Ion Nucleation of Sulfuric Acid and Water Vapor in the Dynamics of Sulfate Aerosol Formation in the Atmosphere

2021 ◽  
pp. 53-60
Author(s):  
A. E. Aloyan ◽  
◽  
A. N. Yermakov ◽  
V. O. Arutyunyan ◽  
◽  
...  
Keyword(s):  
Water Vapor ◽  
Sulfuric Acid ◽  
Three Dimensional ◽  
Ionization Rate ◽  
Sulfate Aerosol ◽  
Aerosol Formation ◽  
Three Dimensional Model ◽  
Aerosol Composition ◽  
Transport And Transformation

The results of one-dimensional calculations of the height profiles of nucleated sulfate aerosol particles for the northern mid-latitudes and tropics in winter are presented. Numerical calculations were performed using a three-dimensional model of the transport and transformation of multicompo- nent gas and aerosol substances in the atmosphere, incorporating photochemistry, nucleation involving neutral molecules and ions, as well as condensation/evaporation and coagulation. It is found that the resulting dynamics of the formation of aerosol particle nuclei is not a simple sum of ion and binary (water vapor/sulfuric acid) nucleation rates. This dynamics is determined by the ratio of critical radii of nucleated particles due to binary and ion nucleation of these substances (rcr_bin and rcr_ion) depending on temperature, relative humidity, and ionization rate. This should be taken into account in modeling the gas and aerosol composition of the atmosphere and comparing calculated and observed data.

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