The mining district of Montevecchio is rich ore deposits, such as lead, zinc, copper, silver, tin and iron, which made him one of the most important in Western Europe.

One can distinguish between:

- STERILE MATERIAL (landfill): not having undergone any processing is comparable, as
pollution potential, the natural geochemical background.

Characteristics of the tailings dumps: instability of the substrate; pollutants; difficult to vegetative growth.

- DEPOSITS OF WASTE AND SLUDGE: having undergone industrial processes are dangerous sources' pollution for soil and water and then for agriculture and pasture.

Such pollution is derived from the oxidation of sulphides (galena and zinc blende) which have the effect of acidification of the substrate with release of zinc and lead.

a) Heavy metals: accumulate in soils, surface water and groundwater, present in the formations
     rocks of the mining districts. (Acid Drainage - DA).It has acid production when materials
     rich in sulfur content in the waste rock and tailings are exposed to oxygen and water and
     they react to form sulfuric acid. Process occurring in nature but accelerated by the activities
     mining. In the environment of landfill mining the mass sterile or gangue, consisting of heavy metals, not
     treated, at low pH, makes that the rocks are altered by oxidation, yielding the heavy metals to the water
     surface drainage and contaminating aquifers.
     One of the most alarming of DA is the persistence in the environment of sulfuric acid, with
     serious repercussions for long-term surface water and groundwater and on life
     water. Once initiated, the process of formation of acids is extremely difficult to stop.
b) Lead: Toxic by inhalation and ingestion, poison, can damage the nervous system. Not coming
     20% is metabolized in the blood and tissues, while the rest is excreted.
c) Cyanide: used to keep in solution the metal to be deposited. Poisoning by inhalation,
     ingestion and skin penetration.

- METAL TOLERANT PLANTS: flora (existing) capable of withstanding such pollution. For example:
a) Ptilostemon casabonae: suitable for sterile materials to expand on the many seeds produced and the high
     power of the root;
b) Rumex bucephalophorus: in particular of river beds;
c) Resedo - Limonietum merxmuelleri: (Iglesias);
d) Garrigues: very common plant formations consisting of small shrubs and herbaceous annuals and perennials (eg Genista sulcitana)

As the plants are setting favor the formation of an embryo that is taking over land plants more tolerant and less demanding of soil pollution.

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