Langmuir adsorption model

Engineering

Adsorption

Specific surface area

Fourier transform infrared spectroscopy

Catalysis

Desorption

Organic chemistry

Inorganic chemistry

Aqueous solution

Chemistry

Endothermic process

Activated carbon

BET theory

Chemical engineering

Mesoporous material

Journal of Hazardous Materials

Activated carbon (ENAC) was prepared by NaOH activation, using macroalgae (Enteromorpha clathrate) as raw material. The prepared activated carbon has a large surface area (1238.491 m2 g-1) and its total pore volume and average pore size are 0.6823 cm3g-1 and 2.2038 nm, respectively. The ENAC was characterized by SEM, FTIR, BET and XPS. The effects of contact time (0-960 min), initial tetracycline (TC) concentration (50-500 mg L-1), temperature (30-50 °C) and initial pH (2-11) on TC adsorption were evaluated. The adsorption isotherm and adsorption kinetics were discussed. Results showed that the adsorption isotherm was the Langmuir model, and the adsorption process can be described by the pseudo-second-order model. The N2 adsorption-desorption isotherm was type IV, indicating that the activated carbon had mesoporous structure. Thermodynamic analysis showed that the adsorption process was endothermic and spontaneous. The maximum adsorption capacity of TC was 381.584 mg g-1. Density functional theory (DFT) was used to simulate and analyze the adsorption process, and the influence of different types of N on the adsorption was expounded. The results showed that there are electrostatic interactions, π-π interactions and hydrogen bonding between the adsorbent and TC. These results indicated that the prepared ENAC had a great application prospect in the removal of antibiotics from aqueous solution.

Adsorption modeling, thermodynamics, and DFT simulation of tetracycline onto mesoporous and high-surface-area NaOH-activated macroalgae carbon