Morphological transformation of exogenous lead in soil

Most of your topics are paid journals. I will send you a pdf file to give you the chemical forms and transformation of lead, copper and cadmium in agricultural soils in the Yangtze River Delta and the Pearl River Delta. If you think you can help, give points.

Lead is mainly found in the form of bivalent inorganic compounds in soil, and very few are tetravalent. It mostly exists in insoluble forms such as Pb(OH)2, PbCO3 or Pb3(PO4)2, so the mobility of lead and the absorption of lead by crops are greatly reduced. Soluble lead levels are generally higher in acidic soils because H+ in acidic soils dissolves lead from insoluble lead compounds.

Harm to plants.

The uptake and accumulation of lead by plants is determined by the concentration of lead in the environment, soil conditions, and the size and shape of the plant's leaves. In general, the lead absorbed by plants accumulates mainly in the roots, and only a few are transferred to the aerial parts. Lead accumulates in roots, stems and leaves, which can affect the growth and development of plants and cause plant damage.

The harm of lead to plants is manifested in chlorophyll.

declines, hindering plant respiration and photosynthesis.

Hazards to animals.

The danger of lead to animals is cumulative poisoning. Lead is a poison that acts on various systems and organs of the animal body, and can interact with a range of proteins, enzymes and amino acids in the body.

within the functional group.

Complexation interferes with many biochemical and physiological activities of the body, resulting in harm to the organs of the whole body of the animal.

Harm to human health.

Lead does not have any physiological function in the human body, and the ideal blood lead level in the human body should be zero. However, due to the prevalence of lead in the environment, the vast majority of individuals have some amount of lead present in some way, and lead levels above a certain level can be a health hazard.

: The heavy metal element cadmium enters the soil and remains in the tillage layer due to slow migration, so it is polluted by aquatic products.

: Once the heavy metal element cadmium enters the soil, it will remain in the tillage layer for a long time. Because it moves slowly, it generally does not pollute groundwater.

Weakly acidic, oxidized, reduced, residue.

Do you understand the form of existence of metals in nature?

In addition to preventing the adsorption of metal atoms on the container wall, the main reason for adding nitric acid is to prevent the hydrolysis of lead ions. Lead nitrate is a strong acid and weak alkali salt, which is hydrolyzed in aqueous solution to generate a white precipitate Pb(OH)2 that is insoluble in water Hydrolysis: Pb(NO3)2 + 2H2O, and the product is pb(NO3)2 + 2H2O

PB(OH)2+ 2HNO3, so nitric acid is added to prevent hydrolysis.