Fruit peels based natural adsorbents used in wastewater treatment: A review

The spontaneous urbanization development forced on industrialization evolution which increase the production of huge amounts of contaminated water. These contaminated water discharge in water reservoirs in untreated or semi treated form that contaminates the pure water containing dyes, heavy metals, nutrients, and emerging contaminants. Population growth cause stress to the need of fresh water for survival of life hence various conventional methods are applied for wastewater treatment. These methods have some limitation as expensive, energy-intensive, and may generate secondary pollution. In recent years, fruit peels based natural adsorbents that have abundant availability renewable agro-waste—have gained significant attention as low-cost, eco-friendly materials frequently applied for wastewater treatment. Some fruit peels like banana, orange, lemon, pomegranate, mango, and apple peels which rich in cellulose, hemicellulose, lignin, pectin, and various functional groups (–OH, –COOH, –NH₂), that empower effective adsorption of pollutants. This review emphasized about the sources, composition, alteration process, adsorption mechanisms, and applications of fruit peels in the removal of dyes, heavy metals, and other contaminants from wastewater. Advantages, limitations, and future prospects for large-scale application are also discussed.