RETRACTED: Adsorption of heavy metals from wastewater by chitosan: A review (Retracted article. See vol. 26, 2025)

With the progress of human civilization, the development of technology and the increasing population, the world is currently facing an important problem called pollution, which threatens the lives of the inhabitants of the planet, so that in every country, environmental protection is a serious concern of the statesmen. Pollution caused by the accumulation of soil and water from persistent toxic compounds such as chemicals, salts, heavy metals and radioactive substances are the causes of diseases that have inconsistent effects on the growth and health of animals and humans. The release of heavy metals in the environment due to industrialization and the expansion of urbanization has brought great problems all over the world, and the increase in environmental pollution by heavy metals has caused serious concerns due to their carcinogenic properties, indestructibility and biological accumulation. Adsorption of heavy metals from industrial effluents is one of the important environmental issues. So far, various methods have been considered for the adsorption of these metals, and the use of biological adsorption is one of these methods. There are various natural and synthetic adsorption, each of which has specific advantages, recently chitosan adsorption and also chitosan composites have been used. Being economical in terms of economy, easy access and compliance with environmental standards are among the advantages of adsorption method. In this study, the basis of performance, advantages and disadvantages of different adsorption methods finally chitosan adsorbent and chitosan nanofibers and composites have been discussed.