HKUST-1-Derived Cu@Cu(I)@Cu(II)/Carbon adsorbents for ciprofloxacin removal with high adsorption performance

Towards sorptive eradication of pharmaceutical micro-pollutant ciprofloxacin from aquatic environment: A comprehensive review

Antibiotics are widely prioritized pharmaceuticals frequently adopted in medication for addressing numerous ailments of humans and animals. However, the non-judicious disposal of ciprofloxacin (CIP) with concentration levels exceeding threshold limit in an aqueous environment has been the matter of growing concern nowadays. CIP is found in various waterways with appreciable mobility due to its limited decay in solidified form. Hence, the effective eradication strategy of this non-steroidal anti-inflammatory antibiotic from aqueous media is pivotal for preventing the users and the biosphere from their hazardous impacts. Reportedly several customary techniques like reverse osmosis, precipitation, cross-filtration, nano-filtration, ion exchange, microbial remediation, and adsorption have been employed to eliminate CIP from water. Out of them, adsorption is ascertained to be a potential method because of lesser preliminary investment costs, ease of operation, greater efficiency, less energy usage, reduced chemical and biological slurry production, and ready availability of precursor materials. Towards remediation of ciprofloxacin-laden water, plenty of researchers have used different adsorbents. However, the present-day challenge is opting the promising sorbent and its application towards industrial scale-up which is vital to get reviewed. In this article, adsorbents of diverse origins are reviewed in terms of their performances in CIP removal. The review stresses the impact of various factors on sorptive assimilation of CIP, adsorption kinetics, isotherms, mechanism of ionic interaction, contrivances for CIP detection, cost estimation and reusability assessments of adsorbents also that may endorse the next-generation investigators to decide the efficacious, environmental appealing and cost-competitive adsorbents for effective riddance of CIP from wastewater.

Production of MgFe2O4/activated carbons derived from a harmful grass Cynodon dactylon and their utilization for ciprofloxacin removal

Cynodon dactylon, an invasive species, exhibits its robust adaptability, reproduction and nutrient regime against the local species. Taking advantage of this harmful grass as a raw precursor to produce valuable materials for wastewater treatment has paid much attention. Herein, we report on the fabrication of Cynodom dactylon derived MgFe2O4@AC with a main goal of effective removal of ciprofloxacin antibiotic from water. Our findings showed that MgFe2O4@ACK1 composites attained mesoporous textures, high specific surface areas (884.3-991.6 m2 g-1), and MgFe2O4-20%@ACK1 was the most effective with a very high removal efficiency of 96.7%. The Elovich model was suitable for describing the kinetic of adsorption with (Radj)2 of 0.9988. Meanwhile, the isotherm data obeyed the Langmuir model corresponding to (Radj)2 of 0.9993. Qmax value of MgFe2O4-20%@ACK1 was determined at 211.67 mg g-1. The proposed adsorption mechanism primarily comprises five routes as follows, (i) pore-filling, (ii) π-π interaction, (iii) electrostatic interaction, (iv) hydrogen bonding, and (v) hydrophobic interaction. MgFe2O4-20%@ACK1 adsorbent could reuse with three cycles. We recommend that MgFe2O4/ACs derived from Cynodom dactylon could be high-efficiency adsorbents for the elimination of antibiotics.

Metal-Organic Frameworks/Graphdiyne/Copper Foam Composite Membranes for Catalytic Applications

Graphdiyne (GDY) with a three-dimensional network structure was synthesized on a copper foam (CF) via an in situ Glaser-Hay coupling reaction. A metal-organic framework/GDY composite membrane was designed and synthesized for the first time. CF serves as a template and catalyst for the directed polymerization of GDY membranes. The catalytic activities of HKUST-1/GDY/CF membrane in wet peroxide oxidation of phenol, oxidation of benzyl alcohol, and ring opening of epoxide were studied. The composite membrane has the advantages of appropriateness for continuous operation, simple use process, easy recycling, high catalytic efficiency, etc. It was found that the incorporation of GDY can facilitate electron transfer and effectively improve the catalytic activity of HKUST-1 in membrane catalysis.

Label free dual-mode sensing platform for trace level monitoring of ciprofloxacin using bio-derived carbon dots and evaluation of its antioxidant and antimicrobial potential

Being a persuasive antibiotic, ciprofloxacin is widely administered to patients and its excessive discharge has generated a keen interest among researchers for its detection in water resources. Therefore, the current work utilizes the virtues of carbon dots synthesized from the leaves of Ocimum sanctum as an economical and convenient bimodal stratagem for the detection of ciprofloxacin via an electrochemical and fluorometric approach. The insight into photostability, size, morphology, and optical studies of the carbon dots was tested to enhance their scope in sensing. The excellent photoluminescence-based excitation-dependent behavior with a quantum yield of 46.7% and non-requirement of any kind of labeled surface variations for amending their fluorescence and electrochemical properties have further supported the utilization of as-prepared carbon dots in trace-level monitoring of ciprofloxacin. The fluorescence emission intensity and peak current were enhanced by many folds via the application of Ocimum sanctum-derived carbon dots. The synergetic effect of carbon dots has possessed a linear relationship between the peak current/emission intensity within the range of 0 to 250 μM of ciprofloxacin and the lowest detection limit value was found to be 0.293 and 0.0822 μM with fluorometric and electrochemical methods, respectively. The sensor demonstrated excellent applicability for the estimation of ciprofloxacin and acts as a high-performance dual sensor for further applications.

Enhanced Visible-Light-Responsive Photocatalytic Degradation of Ciprofloxacin by the CuxO/Metal-Organic Framework Hybrid Nanocomposite

Ciprofloxacin (CIP) is a commonly used antibiotic, however, once in the environment, it is highly toxic with a poor biodegradability. Given these attributes, an effective strategy for the removal of CIP is urgently needed for the protection of water resources. Herein, a novel copper metal-organic framework (CuxO/MOF) multifunctional material has been produced, in this work, by the calcination of Cu-MOF urea at 300 °C, in the presence of a 5% H2 atmosphere. The morphological, structural, and thermal properties of the prepared CuxO/MOF were determined through various techniques, and its photocatalytic behavior was investigated for the degradation of CIP under visible-light irradiation. The prepared CuxO/MOF bifunctional material is presented as a graphitic carbon-layered structure with a particle size of 9.2 ± 2.1 nm. The existence of CuO-Cu2O-C, which was found on the CuxO/MOF surface, enhanced the adsorption efficiency and increased the photosensitivity of CuxO/MOF, towards the degradation of CIP in aqueous solutions. The tailored CuxO/MOF, not only shows an excellent CIP degradation efficiency of up to 92% with a constant kinetic rate (kobs) of 0.048 min−1 under visible light, but it can also retain the stable photodegradation efficiency of >85%, for at least six cycles. In addition, CuxO/MOF has an excellent adsorption capacity at pH 6.0 of the maximum Langmuir adsorption capacity of 34.5 mg g−1 for CIP. The results obtained in this study demonstrate that CuxO/MOF is a reliable integrated material and serves as an adsorbent and photocatalyst, which can open a new pathway for the preparation of visible-light-responsive photocatalysts, for the removal of antibiotics and other emerging pollutants.