A review on functionalized adsorbents based on peanut husk for the sequestration of pollutants in wastewater: Modification methods and adsorption study

The adsorption technique has been observed to be very effective for the sequestration of pollutants in wastewater remediation processes with the material used as the adsorbent playing a crucial role. In this regard, the use of agricultural waste residues has been widely explored owing to their unique properties which enable them to be applied as adsorbents. However, their use in pristine forms leaves much to be desired. Several modification agents have been applied for the treatment of agricultural waste residues with the view of enhancing their adsorption capacity and ameliorating the disadvantages accompanying their use in the pristine state. Due to the abundance of peanut husk generated globally and its cellulosic nature, it has been extensively applied as an adsorbent for the removal of a broad-spectrum of pollutants in wastewater. This makes it a useful model for the design of efficient adsorbents based on agricultural biomass. In this review, the application of functionalized adsorbents, based on peanut husk (an agricultural waste material) for the sequestration of pollutants in aqueous solution, is presented. In a bid to understand the suitability of these functionalized adsorbents, a brief overview on the surface properties of the modified adsorbent, mechanism of adsorption process as well as advantages associated with the modified agents are presented. This review presents cost-effective and efficient adsorbents based on peanut husk for the sequestration of wastewater which can aid in the design of novel adsorbents hinged on agricultural waste materials for environmental remediation processes.