Trends in Adsorption Mechanisms of Fruit Peel Adsorbents to Remove Wastewater Pollutants (Cu (II), Cd (II) and Pb (II))

Currently, there is increasing interest on low cost and commercially available materials for the adsorption of heavy metals. The vital benefits of adsorption technologies are its potential in reducing the concentration of heavy metal ions using low-cost adsorbent materials. Fruit peel wastes (FPW) are readily available in abundance. Furthermore, it has a high potential as a sustainable adsorbent due to its large quantity of lignocellulosic materials. Realizing this potential, there are many studies on various fruit peels waste adsorbents used in the removal of Pb (II), Cu (II) and Cd (II) ions from wastewater. However, there is no comprehensive review of these adsorbents, especially on the factors that influenced the adsorption capacity. Hence, this review aims to study on the various fruit peels waste adsorbents and the factors by comparing the metal binding capacities, metal removal performances, sorbent dosage, optimum pH, temperature, initial concentration and contact time. Finally, the adsorption mechanisms were also discussed.