A review on the current approach for the sustainable production of nanocomposites from agricultural wastes and their application for the adsorption of organophosphate flame retardants

Water pollution caused by emerging organic pollutants such as the halogenated organophosphate flame retardants, has exacerbated the issue of water scarcity. An eco-friendly technology, e.g., the adsorption technique, requires the use of affordable and safe adsorbents. Agricultural waste materials are promising adsorbents for wastewater remediation due to their relative abundance, biodegradability, non-toxic and cost-effective properties. However, most agricultural wastes are not ideal for adsorption in their raw forms and may require physical or chemical pre-treatments/modification, in order to increase the materials' compatibility and natural adsorption properties. Cellulose is an important constituent of plant residues that can be used as a precursor for the production of greener and sustainable industrial nanomaterials. Therefore, in this review, a discourse on the most recent approach/strategies for the modification of a range of agricultural wastes is presented. The result from their applications showed agricultural wastes has great prospects as adsorbents. The challenges encountered in the synthesis of plant-based adsorbents and the development of 3-D structured nanocomposites from cellulose, to circumvent these difficulties is extensively reviewed. Furthermore, the prospects in the application of cellulose beads/ZnO nanocomposites (CB-ZnO) derived from the maize tassel, for the adsorption of the halogenated organophosphate esters from aqueous matrices are presented in this review