Pore creation nanoarchitectonics from non-porous metal-organic framework to porous carbon for adsorptive elimination of sulfanilamide and chloroxylenol from aqueous solution

Highly enhanced chloramphenicol adsorption performance of MIL-53-NH2(Al)-derived porous carbons modified with tannic acid

The worldwide demand for antibiotics has experienced a notable surge, propelled by the repercussions of the COVID-19 pandemic and advancements in the global healthcare sector. A prominent challenge confronting humanity is the unregulated release of antibiotic-laden wastewater into the environment, posing significant threats to public health. The adoption of affordable carbon-based adsorbents emerges as a promising strategy for mitigating the contamination of antibiotic wastewater. Here, we report the synthesis of novel porous carbons (MPC) through a direct pyrolysis of MIL-53-NH2(Al) and tannic acid (TANA) under N2 atmosphere at 800 °C for 4 h. The effect of TANA amount ratios (0%-20%, wt wt-1) on porous carbon structure and adsorption performance was investigated. Results showed that TANA modification resulted in decreased surface area (1,600 m2 g-1-949 m2 g-1) and pore volume (2.3 cm3 g-1-1.7 cm3 g-1), but supplied hydroxyl functional groups. Adsorption kinetic, intraparticle diffusion, and isotherm were examined, indicating the best fit of Elovich and Langmuir models. 10%-TANA-MPC obtained an ultrahigh adsorption capacity of 564.4 mg g-1, which was approximately 2.1 times higher than that of unmodified porous carbon. 10%-TANA-MPC could be easily recycled up to 5 times, and after reuse, this adsorbent still remained highly stable in morphology and surface area. The contribution of H bonding, pore-filling, electrostatic and π-π interactions to chloramphenicol adsorption was clarified. It is recommended that TANA-modified MIL-53-NH2(Al)-derived porous carbons act as a potential adsorbent for removal of pollutants effectively.

Effect of pyrolysis temperature on characteristics and chloramphenicol adsorption performance of NH2-MIL-53(Al)-derived amine-functionalized porous carbons

Several activities such as aquaculture, human and feedstock therapies can directly release antibiotics into water. Due to high stability, low hydrolysis and non-biodegradation, they can accumulate in the aqueous environment and transport to aquatic species. Here, we synthesized amine-functionalized porous carbons (ANC) by a direct-pyrolysis process of NH2-MIL-53(Al) as a sacrificial template at between 600 and 900 °C and utilized them to eliminate chloramphenicol antibiotic from water. The NH2-MIL-53(Al)-derived porous carbons obtained high surface areas (304.7-1600 m2 g-1) and chloramphenicol adsorption capacities (148.3-261.5 mg g-1). Several factors such as hydrogen bonding, Yoshida hydrogen bonding, and π-π interaction, hydrophobic interaction possibly controlled adsorption mechanisms. The ANC800 could be reused four cycles along with high stability in structure. As a result, NH2-MIL-53(Al)-derived porous carbons are recommended as recyclable and efficient adsorbents to the treatment of antibiotics in water.

An Eco-Friendly Adsorbent Based on Bacterial Cellulose and Vermiculite Composite for Efficient Removal of Methylene Blue and Sulfanilamide

In this work, a novel composite of bacterial cellulose (BC) and expanded vermiculite (EVMT) composite was used to adsorb dyes and antibiotics. The pure BC and BC/EVMT composite were characterized using SEM, FTIR, XRD, XPS and TGA. The BC/EVMT composite exhibited a microporous structure, providing abundant adsorption sites for target pollutants. The adsorption performance of the BC/EVMT composite was investigated for the removal of methylene blue (MB) and sulfanilamide (SA) from an aqueous solution. The adsorption capacity of BC/ENVMT for MB increased with increasing pH, while the adsorption capacity for SA decreased with increasing pH. The equilibrium data were analyzed using the Langmuir and Freundlich isotherms. As a result, the adsorption of MB and SA by the BC/EVMT composite was found to follow the Langmuir isotherm well, indicating a monolayer adsorption process on a homogeneous surface. The maximum adsorption capacity of the BC/EVMT composite was found to be 92.16 mg/g for MB and 71.53 mg/g for SA, respectively. The adsorption kinetics of both MB and SA on the BC/EVMT composite showed significant characteristics of a pseudo-second-order model. Considering the low cost and high efficiency of BC/EVMT, it is expected to be a promising adsorbent for the removal of dyes and antibiotics from wastewater. Thus, it can serve as a valuable tool in sewage treatment to improve water quality and reduce environmental pollution.