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Role of biosorption technology in removing cadmium from water and soil

Abstract:

Cadmium is one of the heavy metals, of a nonessential type, since it is not key for the execution of metabolic activities in the cell; that causes the greatest concern due to its bioaccumulation in the food chain, using as sources of contamination water, fruits and plants used for human consumption that have been exposed to contamination by effluents from industries, agricultural and anthropogenic activities, which carry variable amounts of this metal to organic matrices such as bodies of water and soils. Its effects depend on the degree of exposure of a person or animal, to the metal, they appear as illnesses or irritations in the skin, going through functioning problems in organs such as the kidneys, liver and lung, until reaching serious diseases that lead to incurable cancers. For this reason, science has developed techniques for the removal of these metals, initially, techniques of synthetic origin with physical and chemical principles, with potential for correct elimination but that in the long term bring secondary problems, such as secondary contamination, generation of sludge and disabling the metal for later reuse. For this reason, green technologies have been generated, such as phytoremediation, bioaccumulation, and biosorption which is the main topic of this writing. Biosorption is basically a mechanism by which inert organic matter, bacteria, fungi, algae and even plants act as sequestrants of metal ions; thanks to ion exchange interactions, or electromagnetic attraction of opposite charges. The structure of the cell walls or cell membranes of these organisms is a great advantage since they have groups that have a greater affinity for the release of electrons to the medium, remaining positively charged and thus attracting negatively charged ions, or vice versa.