Overview of heavy metals and general situation and characteristics of heavy metal pollution

1.

Metal elements are natural constituents of crustal rocks, and are the general term for all elements except hydrogen on the left side of the line from boron (P) to astatine (At) in the periodic table

In the periodic table of the elements, from the atomic number 23 vanadium (V) to 92 axis (U), there are 60 kinds of natural metal elements, 54 of which have a density equal to or greater than 5g/cm ²

2.

Heavy metal pollution refers to environmental pollution caused by heavy metals or their compounds, mainly caused by human factors such as mining, waste gas discharge, sewage irrigation, and the use of heavy metal products that exceed the standard

Most of the heavy metal pollution is accumulated during the long-term mining, processing and industrialization of minerals.

In recent years, China's soil pollution by heavy metals has gradually emerged, and the situation is grim

3.

Heavy metal pollution has the characteristics of concealment, persistence and enrichment

Heavy metal pollution is difficult to identify visually, causing contaminated food to be eaten directly, contaminated water is used for irrigation of farmland, breeding or direct drinking, and contaminated soil is used for agricultural production

Heavy metals are widely distributed in the environment and organisms.

Bioconcentration, also known as bioconcentration, refers to the phenomenon that biological organisms or many biological groups at the same trophic level accumulate certain elements or difficult-to-decompose compounds from the surrounding environment, so that the concentration of the substance in the biological organism exceeds the concentration in the environment

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