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

Abstract

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

Synthesis and Properties of Cobalt/Nickel-Iron-Antimony(III, V)-Oxo Tartrate Cluster-Based Compounds

“…The vigorous development of printing, leather and other industries has generated a large amount of wastewater containing organic dye pollutants. Thus, it is crucial to solve the environmental pollution problems caused by these species [25][26][27]. In recent years, a number of scholars have utilized metal oxides with precise atomic structures as catalysts for photodegradation of organic dye wastewater [8,28,29].…”

Bridging sustainability and industry through resourceful utilization of pea pods- A focus on diverse industrial applications

“…Agricultural byproducts are rich in bioactive compounds, including terpenoids, polyphenols, alkaloids, and tannins, which have antioxidant, anti-inflammatory, and other beneficial effects ( Sorrenti, Burò, Consoli, & Vanella, 2023 ). These compounds can be used as low-cost adsorbents for the removal of potentially toxic elements from wastewater, with high efficiency and bioadsorption capacity ( Ungureanu et al, 2023 ). Additionally, phytochemicals derived from these byproducts have valuable properties, such as antioxidant, antimicrobial, and anti-cancer activity, and can be applied in various industries, including pharmaceuticals, food production, and wastewater remediation ( Oleszek, Kowalska, Bertuzzi, & Oleszek, 2023 ).…”

Microbial-Based Heavy Metal Bioremediation: Toxicity and Eco-Friendly Approaches to Heavy Metal Decontamination

“…Specifically, bioremediation has demonstrated an economical and ecologically sound approach to extracting heavy metals from contaminated sites [15]. In addition to rice and wheat husk, activated carbon, lignite, agricultural waste, bananas and citrus peels, and green-synthesized nanoparticles have been used as active biosorbents to effectively remove and eradicate heavy metal pollution [16]. In addition, it has been established through scientific research that living microorganisms, encompassing microalgae as well as bacteria, and plants are significantly efficacious in the role of bioremediation agents [10].…”