Secondary Sulfate Minerals from Pyrite Oxidation in Lanmuchang Hg-Tl Deposit, Southwest Guizhou Province, China: Geochemistry and Environmental Significance

Author(s):  
Fengqi Zhao ◽  
Shangyi Gu ◽  
Likai Hao ◽  
Hongguang Cheng ◽  
Lingfei Liu
Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 855
Author(s):  
Fengqi Zhao ◽  
Shangyi Gu

Thallium is a highly toxic metal and is predominantly hosted by sulfides associated with low-temperature hydrothermal mineralization. Weathering and oxidation of sulfides generate acid drainage with a high concentration of thallium, posing a threat to surrounding environments. Thallium may also be incorporated into secondary sulfate minerals, which act as temporary storage for thallium. We present a state-of-the-art review on the formation mechanism of the secondary sulfate minerals from thallium mineralized areas and the varied roles these sulfate minerals play in Tl mobility. Up to 89 independent thallium minerals and four unnamed thallium minerals have been documented. These thallium minerals are dominated by Tl sulfosalts and limited to several sites. Occurrence, crystal chemistry, and Tl content of the secondary sulfate minerals indicate that Tl predominantly occurs as Tl(I) in K-bearing sulfate. Lanmuchangite acts as a transient source and sink of Tl for its water-soluble feature, whereas dorallcharite, Tl-voltaite, and Tl-jarosite act as the long term source and sink of Tl in the surface environments. Acid and/or ferric iron derived from the dissolution of sulfate minerals may increase the pyrite oxidation process and Tl release from Tl-bearing sulfides in the long term.


2013 ◽  
Vol 8 (2) ◽  
pp. 159-178 ◽  

Atrazine, a chlorinated s-triazine group of herbicide is one of the most widely used pesticides in the World. Due to its extensive use, long half-life and various toxic properties, it has very high environmental significance. Up to 22 mg l-1 of atrazine was found in ground water whereas permissible limit of atrazine is in ppb level in drinking water. As per Indian standard there should not be any pesticide present in drinking water. Among many other treatment processes available, Incineration, adsorption, chemical treatment, phytoremediation and biodegradation are the most commonly used ones. Biological degradation of atrazine depends upon various factors like the operating environment, external carbon and nitrogen sources, carbon/ nitrogen ratio (C/N), water content and the bacterial strain. Although, general atrazine degradation pathways are available, the specific pathways in specific conditions are not yet clearly defined. In this paper extensive review has been made on the occurrence of atrazine in surface and ground water bodies, probable sources and causes of its occurrence in water environment, the toxicity of atrazine on various living organisms and its removal by biological processes.


2016 ◽  
Vol 42 (12) ◽  
pp. 1817
Author(s):  
De-Qiang LUO ◽  
Shao-Hua WANG ◽  
Xue-Hai JIANG ◽  
Gang-Hua LI ◽  
Wei-Jia ZHOU ◽  
...  

2013 ◽  
Vol 38 (8) ◽  
pp. 1387-1396
Author(s):  
Mao LIN ◽  
Zheng-Qiang LI ◽  
Zhi-Hong ZHENG ◽  
Jian-Wei LÜ ◽  
Tian-Jin MA ◽  
...  

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