Enhanced remediation of As (V) and Hg (II) ions from aqueous environments using β-cyclodextrin/MCM-48 composite: Batch and column studies

Hybrid structure from mesoporous silica (MCM-48) and beta-cyclodextrin polymer (beta-CD/MCM) was prepared for enhanced remediation of As (V) and Hg (II) ions. The beta-CD/MCM showed promising uptake affinities for As (V) and Hg (II) ions even in the existence of coexisting anions or metal ions. The maximum capacities are 265.6 mg/g and 207.9 mg/g for the As (V) and Hg (II) ions, respectively. The data followed Pseudo-First order kinetic behavior and Langmuir equilibrium properties declaring homogenous and monolayer adsorption. The values of Gaussian energy (6.45 KJ/mol for As (V) and 3.95 KJ/mol for Hg (II) ions) emphasize the physical nature of their uptake by beta-CD/MCM. The thermodynamic studies reflected their adsorption by spontaneous, favorable, and exothermic reactions. Using the beta-CD/MCM as a fixed bed in column system achieved total removal percentages of 72.8 % (As (V)) and 60.4 % (Hg (II)) in addition to total adsorbed metals of 879.8 mg (As (V)) and 717.2 mg (Hg (II)) for 8.1 L of polluted water. Therefore, the synthetic beta-CD/MCM composite is of promising adsorption properties to be applied in the decontamination of As (V) and Hg (II) ions either in batch studies or fixed bed column studies.

Automated summary

The hybrid structure of mesoporous silica and beta-cyclodextrin polymer showed promising uptake affinities for As (V) and Hg (II) ions, with maximum capacities reached at 265.6 mg/g and 207.9 mg/g, respectively. The adsorption process followed Pseudo-First order kinetic behavior and Langmuir equilibrium properties, with physical nature emphasized by Gaussian energy values. Thermodynamic studies demonstrated spontaneous, favorable, and exothermic reactions during adsorption. In column systems, the composite achieved total removal percentages of 72.8% (As (V)) and 60.4% (Hg (II)), making it a promising material for decontamination purposes.