Magnetic biosorbents and their application in water remediation

PAMELA Y. QUINTAS; EMILIANO F. FIORENTINI; MARIA N. OVIEDO; LETICIA B. ESCUDERO

Advanced Magnetic Adsorbents for Water Treatment

Springer

Año: 2021;

Water pollution is caused by the presence of toxic inorganic and organic compounds that come from both natural and anthropogenic sources. The development of the industrial sector has caused the discharge of poor or nontreated residual liquids containing high concentrations of pollutants, such as arsenic, mercury, lead, cadmium, hydrocarbons, and hormones. Although different remediation treatments have been proposed to remove pollutants from contaminated matrices, it is necessary to focus on additional efficient and green technologies. Adsorption has shown promising results for the treatment of pollutants from natural water. In this sense, various types of adsorbents have been synthesized and applied for the removal of different contaminants. Within adsorption, the use of biodegradable materials goes along for the care of the environment and it is equally efficient as or even more efficient than classical chemical adsorbents. However, the phase separation of the biosorbent containing the pollutant from the aqueous phase after the biosorption process is usually made by time-consuming steps like filtration or centrifugation. Moreover, in the case of using some bacteria, it is necessary to make the phase separation with an ultracentrifuge, which is not always available in all laboratories. In this way, magnetic separation has arisen as an alternative to the separation step, offering besides other advantages on the biosorbent response to remove pollutants.In this chapter, we present the most recent advances of using magnetic biosorbents for decontamination of water. A wide variety of contaminants, including metals, metalloids, dyes, and other organic pollutants, are considered. A brief explanation from the creation to the present day of magnetic biosorbents is presented. Different techniques used to characterize magnetic biosorbents are also detailed. The reviewed literature evidences the great potential of magnetic biosorbents for the elimination of different contaminants from aqueous matrices. The contribution of some magnetic nanomaterials to form magnetic biosorbents with biological substrates causes an improvement of the biosorption efficiency due to the high specific surface area, pore volume, and versatility of surface active sites coming from the magnetic nanomaterials. Thus, removal percentages from 70 to 100% are obtained in the majority of the reported works. Other considerations related to biosorption are also covered in this chapter.