Heavy Metal Contamination of the Earth and Water

A large amount of Cr in soil suppresses plant growth. However, some plants can tolerate very high levels of Cr through their physiological mechanisms. Since Cr compounds are a serious health problem considerable effort has been devoted to developing suitable methods for removing Cr contaminated soil and water. Physical and chemical methods for removing Cr from contaminated soil are very difficult and expensive and not suitable for large scale applications 5, 6) phytoremediation, for removing toxic elements from soil Use of plant system Since it is a cost-effective environmentally friendly product, substitutes attract much attention

· Surface water and groundwater are contaminated with heavy metals. High concentrations of these substances pose a threat to the health of humans and animals. To some extent these heavy metals accumulate in the soil and are therefore absorbed by the crops. For example, pig manure contains a large amount of copper. • Acidification due to the release of livestock, feces storage facility, release (volatilization) of ammonia scattered in the soil. Ammonia contributes greatly to acidification of the environment, especially in areas where domestic animals are concentrated.

Rapid urbanization and industrialization resulted in an increase in the disposal of heavy metals and radionuclides in the environment. The rapid increase in the heavy metal contamination problem is due to the increase in industrialization. An important property of heavy metals is the non-biodegradable nature of heavy metal ions. Since metal ions survive in nature, they remain in the environment and cause environmental problems (Leitão, 2009). In water pollution, contamination of heavy metal ions in water is a dangerous level (Regine and Volesky, 2000). Major sources of heavy metal ion contamination include urban industrial aerosols, animal solid waste, mining activities, industrial and agricultural activities (Karnika Alluri et al., 2007).

Human activities are often the reasons for mobilizing natural heavy metal deposits (Vidal> et al., 2000). Heavy metal contamination of drinking water sources is well known and has occurred for generations. Evaporation concentrations in volcanic, geothermal, mining and even dry climates are well known as causes of heavy metal concentrations in groundwater (Karcher et al., 1999). Heavy metals can be mobilized from the original inert minerals through mining activities. Acidic wastewater from mining areas may be enriched with toxic heavy metals (Nordstrom> et al., 2000).