Comparison and Optimization of Operational Parameters in Removal of Heavy Metal Ions from Aqueous Solutions by Low-Cost Adsorbents

Abstract

Removal of heavy metal ions such as cadmium, lead, chromium, and iron from industrial wastewater is one of the most critical environmental problems. In this research, natural and low-cost adsorbents like the tangerine peel, bovine gut, tea waste, and sunflower seed hull were used for adsorption of heavy metals, such as chromium and iron, from contaminated solutions. The effects of environmental factors such as contact time, pH, the amount of adsorbent dose, and the initial concentration of metal ions in synthetic solution were investigated to obtain optimal conditions for the adsorption of heavy metal ions. For separation of chromium metal ion from aqueous solution, tea waste, tangerine peel, bovine gut, and sunflower seeds hull showed adsorption capacity of 85%, 51%, 46%, and 34%, respectively, while for the adsorption of iron (III), the adsorption capacities of tea waste, bovine gut, tangerine peel, and sunflower seeds hull were 96%, 96%, and 87%, respectively. The adsorption isotherms were in decent correlation with the Langmuir and Freundlich isotherm models. The adsorption kinetics of iron and chromium has a proper validation with the pseudo-second-order kinetic model. The BET and FTIR analyses were also reported to investigate the adsorption properties. This study suggests these adsorbents as low-cost and economical materials for the adsorption of chromium and iron ions with a high adsorption rate.

Adsorption of Copper and Lead Ions in a Binary System onto Orange Peels: Optimization, Equilibrium, and Kinetic Study

“…The Langmuir isotherm model assumes that the surface of the bio-sorbent is homogenous, and bio-sorption occurs in a single surface layer. The bio-sorption process is uniform, and the active sites are equal [10]. The model equation is expressed in Equation (3).…”

“…The secondorder polynomial Equation ( 6) with multiple regression analysis was used to generate the responses (percentage removal of Cu 2+ and Pb 2+ ) using the three design factors. The quadratic regression model shows the model parameters generated for the responses; percentage removal of Pb (Y 1 ) and percentage removal of Cu (Y 2 ) written for coded factors as a function of initial concentration (A), adsorbent dosage (B), and the particle size (C) are represented in Equations ( 9) and (10), respectively.…”

Employment and performance of modified chitosan for the removal of copper ions and methylene blue in wastewater

“…It was indicating that the samples are typical mesoporous materials according to IUPAC classification, which reflects the occurrence of capillary condensation phenomenon in the pores. [50,51] These results are inconsistent with the observations obtained from the SEM images.…”

Removal Lead Ions from Aqueous Solutions by Production of Local Natural Materials from Waste Tea and Coffee as an Adsorbent Material (Comparative Study)

“…Contamination of water and air by toxic metals is an environmental concern and hundreds of millions of people are being affected around the world. A new emphasis on agricultural and food sector wastes like coffee grounds, Banana peel, orange peel, rice hull 1 , and other materials like sawdust and fly ash as alternatives to synthetic resins or activated carbon as adsorbents for metalcontaining solutions in sewage systems 2 .…”