Potentials of orange wastes in wastewater treatment technology: A comprehensive review

Abstract

Oranges are popularly consumed globally because of their high nutritional values and antioxidant properties. The leftover orange wastes, readily available as a raw material, can be effectively utilized to produce adsorbents and catalysts that can scavenge and break down a diverse spectrum of pollutants from aqueous solutions. This study explores the potential use of orange waste as a raw material for the preparation of an adsorbent to remove heavy metals, dyes, pesticides, herbicides, polycyclic aromatic hydrocarbons (PAHs), aromatic hydrocarbons, inorganic contaminants, and radioactive ions from water. Additionally, it explores the use of orange waste in treating gaseous pollutants and preparing catalysts for degrading dye, pharmaceutical, and plastic pollutants. Recent research has focused on developing low-cost adsorbents from orange waste and studying its isotherms, kinetics, and thermodynamic properties against pollutants. Critical discussions have been conducted on the isotherm model, kinetic model, and thermodynamic parameters calculations for orange waste-derived adsorbents. Conclusions are drawn from the data presented in the preponderance of published articles on the use of orange waste-derived materials against environmental pollutants. There is a lack of comprehensive review articles on the adsorption and catalytic properties of orange waste-derived materials against various contaminants. Recent research has demonstrated that orange waste could serve as a potential eco-friendly material for the remediation of environmental pollutants.