Globally there is over 20 million ha of land contaminated by heavy metals such as Arsenic (As), Cadmium (Cd), Chromium (Cr), Mercury (Hg), Lead (Pb), Cobalt (Co), Copper (Cu), Nickel (Ni), Zinc (Zn), and Selenium (Se), with the present soil concentrations higher than the geo-baseline or regulatory levels.
These can lead to major problems for the environment and human health.
As to where this pollution comes from, although there is the contribution of contaminants through natural sources like, volcanic, seepage from parental rock, biogenic, and forest emissions, the widespread soil contamination and degradation are majorly caused by anthropogenic activities. Rapid and injudicious industrialization, intensive agricultural practices, faulty mining practices and waste disposals are the major causes of heavy metal contamination of soil.
The pollutants introduced into soil by anthropogenic activities can arise from a plethora of sources. These might be discrete point sources or diffuse sources.
In any case, identifying these sources of contamination is essential, in the first instance, to try to avoid them.
But, in addition, once they have already occurred, it is necessary to know this information so that, before carrying out any action or activity on a soil or site or demolishing buildings or other constructions, it is possible to foresee that this soil is potentially contaminated by heavy metals.
In this way, the relevant investigations can be carried out to proceed appropriately, avoiding unnecessary risks to human health and the environment, and being able to correctly plan the necessary decontamination activities.
What are the different soil remediation techniques to decontaminate soils impregnated with heavy metals?
Soil remediation techniques have been developed to rectify the heavy metal-contaminated sites. They employ containment, extraction/removal, and immobilization mechanisms to reduce the contamination effects through physical, chemical, biological, electrical, and thermal remedy processes.
These techniques demonstrate specific advantages, disadvantages, and applicability. So it must be an expert who determines which one is most suitable for each case.
This article can be found in the 2023 edition of the document. Find the full publication here:
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