Modification of Agricultural Waste Carbon Adsorbents with Iron and Iron Oxide Nanoparticles for Heavy Metals Removal: A Scoping Review of the Literature
Abstract
Introduction: Considering the damage caused by heavy metal pollution, researchers and environmental health organizations have prioritized developing methods to remove heavy metal ions from polluted water. This study reviews existing literature on the use of agricultural waste, as well as the modification of agricultural waste with iron and iron oxides, for heavy metal removal.
Materials and Methods: The systematic review included a search for relevant literature published between 2000 and 2022 in English, with 45 articles being selected for inclusion. After removal of duplicates and screening for eligibility, thematic analysis was conducted to evaluate the advantages and disadvantages of practical, economic methods for preparing and modifying agricultural waste for heavy metal removal.
Results: A total of 45 articles were selected for inclusion, covering the preparation and modification of adsorbents from cellulose sources and agricultural waste. Thematic analysis revealed that agricultural waste is an environmentally friendly adsorbent with a high capacity for removing cadmium, lead, and arsenic from aqueous solutions. Moreover, modified adsorbents with iron and iron oxide nanoparticles demonstrated superior adsorption capacities compared to their unmodified counterparts.
Conclusion: This review highlights the potential of utilizing cellulose sources, particularly processed fruit waste, as a suitable material for preparing carbon-based adsorbents and modifying their surfaces with iron and iron oxide nanoparticles. Their abundance, adsorption capacity, low cost, and availability make them a promising solution for removing heavy metals from aqueous solutions.