Agriculture is one of the economic activities with the most potential in Colombia, given its climatic and geographical conditions. Bean cultivation is classified as climbing, which grows in a ...branched way, and bushy, whose growth occurs up to 70 cm. The objective of this research was to study zinc and iron sulfates in different concentrations as fertilizers capable of increasing the nutritional value of kidney beans (
L.), whose strategy is known as biofortification, and thus determine the most effective sulfate. The methodology details the sulfate formulations, their preparation, the application of additives, sampling and quantification methods of total iron, total zinc, °Brix, carotenoids, chlorophylls a, b, and antioxidant capacity using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method in leaves and pods. As for the results, it was found that biofortification with iron sulfate and zinc sulfate is a strategy that favors the country's economy and human health, because it allows the increase of minerals, antioxidant capacity and total soluble solids.
The presence of emerging contaminants in wastewater poses a global environmental challenge, requiring the development of innovative materials or methods for their treatment. This study focused on the ...production of green functionalized carbon nanotubes (CNTs) and using them in the adsorption of the pharmaceuticals Losartan (LOS) and Diclofenac (DIC). The efficiency of the methodology was verified by characterization techniques. Elemental composition analysis indicated a significant increase in the iron content after the green functionalization, proving the effectiveness of the method. Thermogravimetric analysis showed similar thermal degradation profiles for pristine CNTs and functionalized CNTs, indicating better post-functionalization thermal stability. BET analysis revealed mesoporous characteristics of CNTs, with increased surface area and pore volumes after functionalization. X-Ray diffraction confirmed the preservation of the lattice structure of the CNTs post-functionalization and post-adsorption, with changes in peak broadening suggesting surface modifications. LOS and DIC adsorption were evaluated via kinetic studies at four different concentrations (0.1–0.4 mmol/L) that were best represented by the pseudo-second order model, suggesting chemisorption mechanisms, with faster and higher uptakes for DIC (0.084–0.261 mmol/g; teq = 5 min) when compared to LOS (0.058–0.235 mmol/g; teq = 20 min). The curves were also studied via artificial neural networks (ANN) and revealed that the best ANN architecture for representing the experimental data is a network with 3 5 5 2 neurons trained using the Bayesian-Regularization algorithm and the Log-sigmoid (hidden layers) and Linear (output layer) transfer functions. The desorption study showed that CaCl2 had better performance in CNT regeneration, reaching its removal capacity above 50% up to 3 cycles, for both pharmaceuticals. These findings reveal the potential of the developed material as a promising adsorbent for targeted removal of pollutants, contributing to advances in the remediation of emerging contaminants and the application of artificial intelligence in adsorption research.
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•Green-functionalized carbon nanotubes were used to remove diclofenac and losartan.•The structural analysis confirmed the success of the metal impregnation.•Kinetic investigation revealed that diclofenac has greater uptake than losartan.•ID model best described the LOS kinetics and EMTR model best fitted the DIC data.•Artificial Neural Network accurately predicted adsorption for both contaminants.
This paper investigated the uptake of CIP and OFL in single and multicomponent adsorptive systems using modified carbon nanotubes (CNTs) as adsorbent material. The characterization analyses of the ...pre- and post-process material by XPS, TG/DTG, FT-IR, SEM/EDS, and XRD helped in the elucidation of the mechanisms, indicating greater involvement of n-n and π -π interactions. In the kinetic studies, the simple systems with CIP and OFL were similar, both showed equilibrium time around 20/30 min and increased adsorptive capacity with increasing initial drug concentration. In the multicomponent system, different fractions of CIP and OFL were tested and the time to reach equilibrium also varied between 20 and 30 min. In general, the adsorption capacity of CIP is slightly lower than that of OFL under the conditions tested. The selectivity analysis of the system showed that the selectivity's of the two drugs are identical in equimolar fractions. The mathematical modeling of the kinetic data indicated that in monocomponent systems, the model of pseudo-second order (PSO) adequately described both CIP and OFL kinetics. Furthermore, with the implementation of Artificial Neural Networks (ANN), it was possible to obtain a more assertive prediction of the behavior of single and binary systems.
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•Investigation of single and competitive adsorption of ciprofloxacin and ofloxacin.•Carbon nanotubes were functionalized with iron nanoparticles via the green route.•Ofloxacin showed a greater adsorption preference than ciprofloxacin.•The main adsorption mechanisms were hydrogen bonds, π-π, and n-π interactions.•Artificial neural network successfully predicted single and binary kinetic data.
A clay-based adsorbent (CBA) was purified from a sustainable precursor (raw clay, RC), which was obtained from the Amazon region in Brazil. The CBA was characterized using X-ray diffraction (XRD), ...Fourier Transform Infrared spectroscopy (FTIR), Brunauer-Emmet-Teller surface area (S
BET
, RC = 23.386 m
2
.g
−1
, CBA = 33.020 m
2
.g
−1
), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), thermogravimetric analysis (TGA), cation exchange capacity (CEC, CBA = 44.75 cmol/kg), and point of zero charge analyses (
pH
PZC
, CBA = 2.20). Subsequently, CBA was used to adsorb basic yellow 2 (BY2) dye from aqueous solutions. A CBA dosage (1 g/L), initial concentration of dye (
C
0
= 15 mg/L), and pH (5.6) were ideal conditions for the BY2 dye removal of ~ 98%. The BY2 kinetics was better represented by the pseudo-first-order (PFO) model while the BY2 equilibrium was well represented by the Sips model, with a maximum adsorption capacity of
q
ms
= 18.04 mg/g at 28 °C. The negative values of ΔG° and ΔH° showed that the studied process is spontaneous and exothermic, while the values of isosteric heat (
∆H
st
, -16 to -20 kJ/mol) suggest a predominance of physical interactions. The molecular chemical reactivity of BY2 was investigated using quantum chemical descriptors calculated based on Density Functional Theory (DFT) optimization of the dye molecule, and the results revealed a large energy gap value (4.3900 eV) and considerable chemical hardness (η = 2.1950 eV). Therefore, the correlation between DFT and experimental results consistently sustains that BY2 dye tends to be adsorbed on the CBA surface by electrostatic interactions, thus, this is the possible adsorption mechanism of this process.
Graphical Abstract
Removal of emerging contaminants from aqueous media is a research topic that has become increasingly relevant. These contaminants include pharmaceutical compounds which are frequently found in the ...environment and, even at low concentrations, they may cause a series of adverse effects in humans and animals. The effective removal of pharmaceutical compounds requires advanced treatments, such as adsorption. Carbon nanotubes (CNTs) have been highlighted as excellent nano-adsorbents for drug removal, while functionalization is often performed on carbon nanotubes to add certain properties to the material and improve its adsorptive capacity. There is a growing interest in performing green route synthesis and functionalization of CNTs, as this can significantly reduce the cost of the entire process. This review presents an overview of studies related to the removal of pharmaceutical compounds, focusing on adsorption systems using conventional and green carbon nanotubes published in between 2011 and May/2022. The adsorptive performance of nanotubes functionalized by green routes and by conventional methods was evaluated by the kinetic, equilibrium and thermodynamic results of recent works. The removal of pharmaceutical compounds using nanotubes functionalized by green routes proved to be comparable to the performance of CNTs obtained by conventional processes, confirming the great potential of green CNTs, since they have the advantages of being ecologically friendly and of potentially reducing the process costs. It was found that, in general, the processes of pharmaceuticals adsorption by carbon nanotubes (conventional or green) are exothermic, spontaneous, and have physisorption as their main mechanism. The Langmuir and PSO models best describe the isotherms and adsorption kinetics, respectively. Parameters such as temperature, pH, concentration, adsorbent dosage, and type of functionalization significantly influenced the uptake behavior and the contaminant removal efficiency. There was a lack of studies on adsorption of PHCs by nanotubes synthesized using green routes, as well as few studies on dynamic systems or focusing on the regeneration of CNTs. Therefore, future research may focus on in-depth investigations of the pharmaceuticals adsorption process using nanotubes obtained by green routes, further development of studies in dynamic systems, as well as effective techniques for the desorption/reuse of CNTs.
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•Pharmaceuticals removal in aqueous media by different methods was reported.•Adsorption of pharmaceuticals using carbon nanotubes (CNTs) was highlighted.•Kinetic, equilibrium, and thermodynamic parameters were discussed.•Performance evaluation of CNTs functionalized by green and conventional routes.•Future challenges for green CNTs to remove pharmaceuticals were presented.
The existence of residual concentrations of pharmaceutical substances in wastewater may impact the local ecosystem and human health, thus, it is required to mitigate the occurrence of these ...pollutants in effluents. This study performed the equilibrium adsorption in single and multi-component systems for two drugs (ciprofloxacin-CIP and ofloxacin-OFL) onto multi-walled carbon nanotubes, which were functionalized using a green route. Adsorption analyses were performed in batch aqueous systems in single- and multi-component mixtures at 25, 35, and 50 °C. Moreover, multi-component interaction was evaluated in equimolar (1:1) and non-equimolar (1:3 or 3:1) binaries of CIP with OFL. The results indicated that, for all systems evaluated, temperature did not majority influence the adsorption process. Even so, the adsorbed amount of antibiotics was slightly higher at the highest temperature (single-component systems: 0.433 mmol CIP. g−1 and 0.457 mmol OFL. g−1; and multi-component system: 0.958 mmol. CIP.g−1 and 0.872 mmol. OFL.g−1), indicating an endothermic process. The adjustment of the isothermal models indicated that the Sips and the Langmuir-Freundlich models were those that best fit the isotherms for the studied single-component and multi-component systems, respectively. Finally, artificial intelligence techniques were employed as an alternative to adjust the experimental data and revealed greater accuracy in calculating the observed results than traditional equilibrium models.
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•Single and competitive adsorption of Ciprofloxacin and Ofloxacin was investigated.•Carbon nanotubes were functionalized with iron nanoparticles via the green route.•Sips and Langmuir-Freundlich models better fit the data for single and binary systems.•ANFIS modeling also returned greater accuracy than traditional equilibrium models.•MWCNT-E is very promising for the removal of antibiotics from aqueous media.
Emerging pollutants such as pharmaceuticals and endocrine disruptors are found in sewage systems and wastewater treatment plants in low concentrations. After being discharged into the river, these ...pollutants can contaminate surface and groundwater, causing harms to human health and to the environment. Due to this problem, this study aimed to produce functionalized carbon nanotubes (CNTs) impregnated with iron (Fe) nanoparticles produced from green synthesis for the adsorption of five pharmaceuticals and an endocrine disruptor: ciprofloxacin, diclofenac sodium, losartan, ofloxacin and propranolol, and bisphenol-A. To demonstrate the efficiency of the green synthesis, Fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses were performed. Affinity adsorption tests, molecular simulation via density functional theory, and the construction of an artificial neural network (ANN) were performed to evaluate the adsorbents performance. Characterization analyses indicated that the synthesis process of the green route was successful in the production of solids. The green functionalization of nanotubes previously composed with hydroxyl and carboxyl groups showed the best results in the adsorption tests (>80%), except for bisphenol A, which presented better results with the nanotube constituted by hydroxyl group (100%). Bisphenol A and propranolol molecules proved to be less reactive than the others and the constructed ANN was able to satisfactorily predict the adsorption capacity based on independent variables. Therefore, it can be concluded that carbon nanotubes impregnated with iron nanoparticles prepared by green synthesis are promising for the removal of pharmaceuticals and endocrine disruptors from aqueous media.
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•Functionalized multi-walled carbon nanotubes were modified by green synthesis.•Several plant extracts were used to reduce the metal on the nanotube surface.•Functionalized and modified nanotubes show promise in removing emerging contaminants.•Molecular modeling was used to analyze the reactivity of adsorbate molecules.•An Artificial Neural Network could satisfactorily predict the adsorption capacity.
Large studies on bedaquiline used to treat multidrug-resistant (MDR-) and extensively drug-resistant tuberculosis (XDR-TB) are lacking. This study aimed to evaluate the safety and effectiveness of ...bedaquiline-containing regimens in a large, retrospective, observational study conducted in 25 centres and 15 countries in five continents.428 culture-confirmed MDR-TB cases were analysed (61.5% male; 22.1% HIV-positive, 45.6% XDR-TB). MDR-TB cases were admitted to hospital for a median (interquartile range (IQR)) 179 (92-280) days and exposed to bedaquiline for 168 (86-180) days. Treatment regimens included, among others, linezolid, moxifloxacin, clofazimine and carbapenems (82.0%, 58.4%, 52.6% and 15.3% of cases, respectively).Sputum smear and culture conversion rates in MDR-TB cases were 63.6% and 30.1%, respectively at 30 days, 81.1% and 56.7%, respectively at 60 days; 85.5% and 80.5%, respectively at 90 days and 88.7% and 91.2%, respectively at the end of treatment. The median (IQR) time to smear and culture conversion was 34 (30-60) days and 60 (33-90) days. Out of 247 culture-confirmed MDR-TB cases completing treatment, 71.3% achieved success (62.4% cured; 8.9% completed treatment), 13.4% died, 7.3% defaulted and 7.7% failed. Bedaquiline was interrupted due to adverse events in 5.8% of cases. A single case died, having electrocardiographic abnormalities that were probably non-bedaquiline related.Bedaquiline-containing regimens achieved high conversion and success rates under different nonexperimental conditions.
•Treating MDR-TB is complicated, long and expensive.•Bedaquiline (BQ) is a new active drug to treat MDR-TB.•No study evaluated safety and effectiveness of surgery in BQ-treated patients.•57 ...BQ-exposed cases resistant to 7 drugs (median) underwent surgery in 9 countries.•60% of cases initiated BQ after surgery, 36.4% before and completed it afterwards.•90% culture-converted and 69.1% achieved treatment success at the end of treatment.
No study evaluated the contribution of adjunctive surgery in bedaquiline-treated patients. This study describes treatment outcomes and complications in a cohort of drug-resistant pulmonary tuberculosis (TB) cases treated with bedaquiline-containing regimens undergoing surgery.
This retrospective observational study recruited patients treated for TB in 12 centres in 9 countries between January 2007 and March 2015.
Patients who had surgical indications in a bedaquiline-treated programme-based cohort were selected and surgery-related information was collected. Patient characteristics and surgical indications were described together with type of operation, surgical complications, bacteriological conversion rates, and treatment outcomes. Treatment outcomes were evaluated according to the time of surgery.
57 bedaquiline-exposed cases resistant to a median of 7 drugs had indication for surgery (52 retreatments; 50 extensively drug-resistant (XDR) or pre XDR-TB). Sixty percent of cases initiated bedaquiline treatment following surgery, while 36.4% underwent the bedaquiline regimen before surgery and completed it after the operation. At treatment completion 90% culture-converted with 69.1% achieving treatment success; 21.8% had unfavourable outcomes (20.0% treatment failure, 1.8% lost to follow-up), and 9.1% were still undergoing treatment.
The study results suggest that bedaquiline and surgery can be safely and effectively combined in selected cases with a specific indication.
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