Agricultural Byproducts Used as Low-Cost Adsorbents for Removal of Potentially Toxic Elements from Wastewater: A Comprehensive Review

Potentially toxic elements (PTEs) are ubiquitous chemical compounds in the environment due to contamination of air, water, or soil. They primarily sourced from fossil fuel combustion, mining and smelting, electroplating, dyes pigments, agricultural treatments, plastic metallic industries. These contaminants can produce various adverse effects when they enter human body also affect crops aquatic ecosystems. To address these issues, researchers developing techniques, including ion exchange, membrane filtration, photocatalysis, electrochemical methods, bioadsorption, combinations processes, reduce levels contaminants, especially wastewater. Among bioadsorption has gained much attention its high efficiency, low cost, abundance adsorbent materials. Agricultural byproducts used as biosorbents include rice husk bran, citrus peel, banana coconut husk, sugarcane bagasse, soybean hulls, walnut almond shells, fiber, barley straws, many others. Biosorption capacity be described using adsorption kinetic models such Elovich, Ritchie’s, pseudo-second-order models, well different isotherm Freundlich, Langmuir, Temkin isotherm, BET models. Both conventional processes influenced by parameters pH, agitation speed, contact time, particle size, concentration material, initial contaminant, type modifying agent used. This review paper aims examine low-cost adsorbents their removal efficiency for PTEs present wastewater, potential decontamination methods.