Modified chitosan adsorbents in pharmaceutical simulated wastewaters: A review of the last updates

Over the past 30 years, the global consumption of pharmaceuticals has risen by almost 3 times. Despite being fundamental to the protection of human life, pharmaceuticals have been implicated as a considerable source of environmental pollution, owing to the various ways that they and their components end up into water bodies, resulting in the gradual contamination of their surrounding environment. Technological approaches are required to address such a challenge should be both competent and cost-effective. A wide variety of treatments has been assessed, concluding that the adsorption method is an appealing, simple but powerful tool for the extraction of pollutants. More specifically, the use of Chitosan and its modifications through physicochemical methods have received the spotlight as an emerging solution for the elimination of organic pollutants from aqueous media. The presence of amino and hydroxyl groups provides modification sites that allow for various potential interactions between chitosan and pollutants, such as pharmaceuticals. This work examines the trends in chitosan modifications and their effectiveness in eliminating pharmaceuticals through adsorption treatments. The adsorption mechanisms have also been studied. This review classifies the pharmaceuticals studied in subcategories, while determining the characteristics of the adsorbents used during the removal effort. The importance of this work lies in the assembly of published works related to chitosan and its modifications (2018–2021), and the summarization of the key findings with regard to their capacity to eliminate pharmaceuticals from aqueous solutions.