Comparison of surface-engineered superparamagnetic nanosorbents with low-cost adsorbents of cellulose, zeolites and biochar for the removal of organic and inorganic pollutants: a review

Industrialization and human activities have led to pollution of ecosystems by metals and dyes, calling for advanced remediation methods. For instance, removal of water pollutants has been recently done using low-cost adsorbents. Here we review adsorbents based on cellulose, zeolites, biochar and nanomaterials. Hybridized nanosorbents show adsorption capacities up to five times higher than single materials, due to the combination of functions such as carboxyl, amino, thiol, hydroxyl, vinyl, metals and phenolics. Integrating metals having high magnetization and superparamagnetic properties improves reusability up to 10 cycles with minimal loss of pollutant removal efficiency.