How is arsenic formed in nature?
Inorganic arsenic compounds are found in soils, sediments, and groundwater. These compounds occur either naturally or as a result of mining, ore smelting, and industrial use of arsenic. Organic arsenic compounds are found mainly in fish and shellfish.
What is the nature of arsenic?
Chemical Characteristics Arsenic (As) is a natural element, ubiquitous in the environment, cycling through water, land, air, and living systems. It is a metalloid, possessing both metallic and nonmetallic properties, and is the third element in Group VA of the periodic table.
How does arsenic move through the environment?
Arsenic occurs naturally in soil and minerals and it therefore may enter the air, water, and land from wind-blown dust and may get into water from runoff and leaching. Volcanic eruptions are another source of arsenic. Arsenic may enter the environment during the mining and smelting of these ores.
Where is the element arsenic found in nature?
Arsenic is a naturally occurring chemical element that is widely distributed in the Earth’s crust. Arsenic levels in the environment can vary by locality, and it is found in water, air, and soil.
Where does arsenic in groundwater come from?
Where and how does arsenic get into drinking water? Arsenic can enter the water supply from natural deposits in the earth or from industrial and agricultural pollution. It is widely believed that naturally occurring arsenic dissolves out of certain rock formations when ground water levels drop significantly.
Is arsenic found free in nature?
Arsenic is ubiquitous in nature and ranks twentieth among the elements in abundance in the Earth’s crust, fourteenth in seawater, and twelfth in the human body (Jomova et al.
How does arsenic get in soil?
Arsenic in soil results from human activities including pesticide use, mining and ore processing operations, operating coal burning power plants, and waste disposal. Sites of former tanneries, which make leather from animal hides, have large amounts of arsenic in the soil.
How does arsenic move in groundwater?
In the presence of oxygen, bacteria can oxidize sulfides instead of organic carbon to generate energy (for these bacteria, reduced sulfur is “food”). Once the sulfide is oxidized to sulfate, it is soluble in water, and releases the arsenic.
How is arsenic introduced in water?
Arsenic is introduced into soil and groundwater during weathering of rocks and minerals followed by subsequent leaching and runoff. In water, particularly groundwater, where there are sulfide mineral deposits and sedimentary deposits deriving from volcanic rocks, the concentrations can be significantly elevated.
How does arsenic get in water?
Answer: Arsenic enters lakes, rivers and underground water naturally when mineral deposits such as rocks containing arsenic erode and dissolve. It may also enter the groundwater through the discharge of industrial and agricultural waste products.
Does arsenic cycle in fresh water?
A review of the occurrence and cycling of arsenic in fresh waters is presented. The fate of arsenic in natural waters has received little attention in past years, in spite of the fact that arsenic is toxic and probably carcinogenic through exposure by drinking water.
What is arsenic?
Arsenic is a naturally occurring element that is widely distributed in the Earth’s crust. It is found in water, air, food, and soil.
How does arsenic get into Earth’s atmosphere?
The estimated arsenic reservoirs and fluxes at the Earth’s surface, including in the shallow crust (Fig. 1 ), show that anthropogenic activities play an important role in dispersing arsenic contamination to the hydrosphere, pedosphere, and atmosphere. Arsenic has been used for many purposes, but especially for pesticides and wood preservation.
What do we know about the chemical properties and reaction paths of arsenic?
Many studies have documented the chemical properties and reaction paths of arsenic species and identified arsenic-metabolizing bacteria with the aim of developing chemical treatment and bioremediation methods for arsenic-contaminated groundwaters (e.g., Takeuchi et al. 2007; Yamamura and Amachi 2014 ).