13.5 Impact of Heavy Metals on Environment
As we know high concentration of metals accumulation in water, soil and wastewater lead to degradation of ecosystem and also adversely affect the human health.
Source and its effect on environment have been mentioned below:
13.5.1 Arsenic
Arsenic is one of the contaminants found in the environment which is notoriously
toxic to man and other living organisms. It is a highly toxic element that exists in
various species, and the toxicity of arsenic depends on its species. Arsenic (atomic
number 33) is a silver-gray brittle crystalline solid with atomic weight of 74.9,
specific gravity 5.73, melting point 817
C (at 28 atm), boiling point 613
C, and
vapor pressure 1 mmHg at 372
C. Arsenic is a semimetallic element with the
chemical symbol “As”. Arsenic is odorless and tasteless and it can combine with
other elements to form inorganic and organic arsenicals. In the environment, arsenic
is combined with oxygen, chlorine, and sulfur to form inorganic arsenic compounds.
13.5.2 Cadmium
Cadmium is the 48th element and a member of group 12 in the periodic table of
elements. The most common oxidation number of cadmium is +2. Cadmium appears
naturally as Cd
2+ , often in complexes with inorganic (e.g., Cl
À
, F
À
) or organic
ligands. The solubility of cadmium is highly dependent on the pH and in acidic soils.
Cadmium is one of the most mobile of heavy metals. Cadmium (Cd) is the 67th most
abundant element in the earth’s crust. Its atomic number is 48; atomic weight 112.4;
density 8.64 g/cm
3 ; melting point 320.9
C; boiling point 767
C.
13.5.3 Chromium
Metal in Group 6 of the periodic table. Chromium metal has the outer electronic
configuration 3d
5 4s
1 and forms compounds in oxidation states II– to VI+. The
extensive organometallic chemistry of Cr is covered in the accompanying comprehensive organometallic chemistry series and this review is generally restricted to the
coordination complexes (oxidation states 0 to VI+).
13.5.4 Lead (Pb)
Lead is known to be toxic to plants, animals, and microorganisms.
Lead (Pb), with atomic number 82, atomic weight 207.19 and a specific gravity of
11.34, is a bluish or silvery-gray metal with a melting point of 327.5
C and a boiling
292
P. Kumar et al.
As we know high concentration of metals accumulation in water, soil and wastewater lead to degradation of ecosystem and also adversely affect the human health.
Source and its effect on environment have been mentioned below:
13.5.1 Arsenic
Arsenic is one of the contaminants found in the environment which is notoriously
toxic to man and other living organisms. It is a highly toxic element that exists in
various species, and the toxicity of arsenic depends on its species. Arsenic (atomic
number 33) is a silver-gray brittle crystalline solid with atomic weight of 74.9,
specific gravity 5.73, melting point 817
C (at 28 atm), boiling point 613
C, and
vapor pressure 1 mmHg at 372
C. Arsenic is a semimetallic element with the
chemical symbol “As”. Arsenic is odorless and tasteless and it can combine with
other elements to form inorganic and organic arsenicals. In the environment, arsenic
is combined with oxygen, chlorine, and sulfur to form inorganic arsenic compounds.
13.5.2 Cadmium
Cadmium is the 48th element and a member of group 12 in the periodic table of
elements. The most common oxidation number of cadmium is +2. Cadmium appears
naturally as Cd
2+ , often in complexes with inorganic (e.g., Cl
À
, F
À
) or organic
ligands. The solubility of cadmium is highly dependent on the pH and in acidic soils.
Cadmium is one of the most mobile of heavy metals. Cadmium (Cd) is the 67th most
abundant element in the earth’s crust. Its atomic number is 48; atomic weight 112.4;
density 8.64 g/cm
3 ; melting point 320.9
C; boiling point 767
C.
13.5.3 Chromium
Metal in Group 6 of the periodic table. Chromium metal has the outer electronic
configuration 3d
5 4s
1 and forms compounds in oxidation states II– to VI+. The
extensive organometallic chemistry of Cr is covered in the accompanying comprehensive organometallic chemistry series and this review is generally restricted to the
coordination complexes (oxidation states 0 to VI+).
13.5.4 Lead (Pb)
Lead is known to be toxic to plants, animals, and microorganisms.
Lead (Pb), with atomic number 82, atomic weight 207.19 and a specific gravity of
11.34, is a bluish or silvery-gray metal with a melting point of 327.5
C and a boiling
292
P. Kumar et al.