Adsorption of cadmium ion from aqueous solutions by copper-based metal organic framework: equilibrium modeling and kinetic studies

Abstract

In the present study, the adsorption behavior of copper-based metal organic framework (Cu-MOF) in the removal of cadmium ion (Cd 2+) from aqueous solution was investigated. The Cu-MOF prepared by solvothermal method was characterized by BET, FTIR, SEM and EDX techniques. Effect of adsorption parameters such as initial Cd 2+ concentration (20-100 mg/L), contact time (20-60 min) and adsorbent dosage (0.1-0.5 g) on the removal efficiency and equilibrium adsorption capacity was investigated at fixed pH and temperature. The results obtained from the batch mode adsorption studies revealed that at initial Cd 2+ concentration of 20 mg/L, contact time of 60 min and adsorbent dosage of 0.5 g, the removal efficiency and equilibrium adsorption capacity of Cd 2+ from the process were 98.62% and 1.9724 mg/g, respectively. The experimental data were evaluated by Langmuir and Freundlich isotherm models. The data fitted well with the Langmuir isotherm, and monolayer adsorption capacity of the Cu-MOF was 219.05 mg/g. The kinetic data were analyzed by using pseudo-first-order, pseudo-second-order and intraparticle diffusion models. The kinetic studies showed that pseudo-second-order model exhibited high correlation coefficients for all the initial Cd 2+ concentrations studied, thus indicating that the theoretical amount of Cd 2+ adsorbed agreed to the experimental values of Cd 2+ adsorbed.

Utilization of agricultural waste adsorbent for the removal of lead ions from aqueous solutions

“…This observation was due to the same number of adsorption sites, which were available for the increasing adsorbate concentration. It could be deduced that at a higher concentration of Pb 2+ ions, the sorption sites on the CMOSW surface for the electrostatic attraction were occupied by more contaminants, thus leading to an increase in equilibrium uptake capacity of the CMOSW adsorbent and a decrease in the removal percentage of the adsorbate [29]. Similar observations were also reported for an adsorptive removal of heavy metals by Moringa stenopetala bark powder [30], prawn shells [31] and paper mill sludge activated carbon [10].…”

Adsorption Performance of Modified Fly Ash for Copper Ion Removal from Aqueous Solution

“…A kinetic model is a mathematical representation of the rate at which a physical or chemical process takes place [43]. The kinetic study indicates the adsorption rate and the efficiency of the adsorbent.…”

Eco-Friendly Materials Obtained by Fly Ash Sulphuric Activation for Cadmium Ions Removal

“…Adsorbent dose should be a parameter studied in the adsorption technique of different pollutants from wastewaters since it has an important role in terms of process economy [38,39]. Determining the optimal dose of the adsorbent was carried out by increasing the FA/H 2 SO 4 dose from 0.2 g/25 mL to 0.5 g/25 mL at an initial concentration of 70 mg/L.…”