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This research aims to know the influence of suspension compared to its crude extract on antibacterial activity, especially for Escherichia coli and Staphylococcus aureus. An independent t-test was used as statistical analysis. The yield of the thick extract obtained was 11.153 % ± 1.032 % and it gave an inhibition zone of 7.878 mm ± 0.301 mm for Escherichia coli and 7.484 mm ± 0.636 mm for Staphylococcus aureus. While the suspensions gave an inhibitory zone of 6.293 mm ± 0.754 mm and 5.140 mm ± 0.121 mm for Escherichia coli and Staphylococcus aureus in sequence. The extract’s particle size followed by suspension was 951.167 mm ± 113.662 nm and 474.000 mm ± 38.500 nm. The independent t-test results showed that the extract and suspension significantly influenced the growth of Staphylococcus aureus and Escherichia coli with sig values of 0.012 and 0.028. In conclusion, the extract had a greater effect than the suspension on the growth of Staphylococcus aureus and Escherichia coli.

Simple electrochemical detection of the antibiotic amoxicillin (AMX) in water is crucial to mitigate health and environmental risks; however, the process requires single-use electrodes, which can increase the waste generated as well as the cost. Cellulose nanofibers (CNFs) are biodegradable materials that can be used as electrode frameworks. In this study, a sensitive single-use CNF-based printed electrode modified with polybenzimidazole (PBI)-wrapped multi-walled carbon nanotubes (MWCNTs) is developed for AMX detection. The CNF-based printed electrode achieved a detection limit of 0.3 μM and exhibited a wider detection range of 0.3–500 μM compared with electrodes developed in previous studies. In addition, the electrode reactions of AMX were electrochemically investigated and found to primarily involve the adsorbed species at low AMX concentrations and be diffusion-controlled at high AMX concentrations. Finally, the printed electrodes were used for the easy and practical determination of AMX in seawater and tap water by a soaking method. Satisfactory results were obtained, and the final concentrations of AMX were determined using simple calibration equations. Therefore, this CNF-based electrode exhibits great potential for practical real-time AMX detection in the field. [ABSTRACT FROM AUTHOR]

This study investigated the biotransformation of methylene blue (MB) by mixed fungal cultures of Gloeophyllum trabeum and Aspergillus oryzae. Equal volumes of A. oryzae and G. trabeum cultures were applied to Erlenmeyer containing MB and incubated at 30°C for 7 days. The change in absorbance of the MB control solution and the solution after application, measured with a UVVisible spectrophotometer, was used to calculate the decolorization. The addition of A. oryzae to G. trabeum cultures showed MB biodecolorization reaching 69.34%, greater than single cultures of G. trabeum and A. oryzae, which were 31.50% and 36.82%, respectively. Metabolite identification from MB biodecolorization by mixed culture using LC-QTOF-MS found the following metabolites: C16H20N3S, C19H22N3SO4, C31H48N3S+. The results of this study showed that the addition of A. oryzae enhanced the percentage of MB decolorization from G. trabeum culture. [ABSTRACT FROM AUTHOR]

A clear understanding of the solubility of gas in ionic liquids (ILs) is important for assessing the feasibility of this fluid as an alternative solvent in gas capture and separation processes. In this work, the solubility of ethane in 16 commercial ILs was measured and predicted using the conductor-like screening model for real solvents (COSMO-RS) at four different temperatures and at pressures up to 2 MPa. Henry's law constants were calculated from the obtained experimental data. The broad range of the chosen set of ILs permits a systematic exploration of the impacts of cation, anion, and alkyl chain length on the solubility of ethane in these fluids. The results showed that the solubility of ethane in ILs could be increased by increasing pressure and decreasing temperature. The obtained experimental and COSMO-RS results showed that (i) the solubility of ethane could be enhanced by increasing the nonpolar character of ionic liquids, such as the alkyl chain length of both cation and anion, (ii) fluorination of the anion reduced the solubility of ethane due to preferential solvation of the solute in ILs, and (iii) the increase of ethane solubility in the series [CnC1im][Tf2N] is not linear with increasing alkyl chain length, which can be explained based on the nano-structural organization of the ILs. Finally, computational modelling using COSMO-RS showed that the increase in the solubility of ethane in ILs could be attributed to more favorable electrostatic–misfit interactions between the gas and the nonpolar region of the fluids. [ABSTRACT FROM AUTHOR]

Ionic liquids are considered as emergent pollutants as these compounds possess high persistence in aqueous solution and toxicity toward aquatic organisms. In this work, the adsorption equilibrium of 27 ionic liquids, with different cation head groups, alkyl chain lengths, and anions, onto ZSM-5 was measured experimentally at several compositions and at temperature 298.15 K and 0.1 MPa. The extensive number of ionic liquids studied allows a comprehensive study on the impact of adsorbate chemical structures toward their adsorption process. The gathered experimental results show that the anions have a dominant effect, when compared to the cation head group and the alkyl chain length, in ruling the adsorption of ionic liquids from aqueous solution onto ZSM-5. The adsorption isotherms reveal that the adsorption process is a combination between Langmuir and Freundlich behaviors, with the latter leading the general process. Moreover, computational modelling using COSMO-RS demonstrates the existence of several molecular forces that rule the adsorption process, reinforcing the idea that the ionic liquid anion rules the adsorption. The results collected in the present work provide new understanding on the molecular mechanism for the development of efficient adsorbents for removal and recovery of ionic liquids from aqueous solution. [ABSTRACT FROM AUTHOR]

Medan orange peel (Mopl), which has been modified using cetyltrimethylammonium bromide (CTAB), has the potential to adsorb methyl orange (MO), and thus it can be used as a supporting material for ZnO. The ZnO is a photocatalytic material that is environmentally friendly, inexpensive, non-toxic, and has a wide band gap value. This study aims to determine the effect of calcination temperature on ZnO and ZnO characteristics due to modification using Mopl-CTAB and its effect on the degradation of MO. This research was carried out by synthesizing ZnO and ZnO/Mopl-CTAB materials using impregnation method and varying the calcination temperatures at 150, 250, 350, and 450 °C. The solid material powder obtained was characterized by using Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX), Brunauer-Emmett-Teller (BET), Fourier Transform Infra Red (FTIR), X-ray Diffraction (XRD), and Diffuse Reflectance Spectroscopy (DRS). Based on the results of the characterization, greater calcination temperature can affect the characteristics of the photocatalyst, including its morphology, functional groups, crystal structure, crystal lattice, crystallinity, surface area, pore size, pore volume, and energy band gap. The MO photodegradation activity test using the synthesized material was conducted under dark and light conditions. The results of the test revealed that the best or optimum material to be used in degrading MO is a calcined material at 450 °C under light conditions. ZnO material using Mopl-CTAB is better in degrading ZnO/Mopl-CTAB 450 °C than ZnO 450 °C. This study found that ZnO material using Mopl-CTAB had a percent removal of 78% in 50 min, while ZnO 450 °C only had a percent removal of 53% in 40 min. The reaction kinetics in dark and light conditions follow the pseudo-second-order kinetic model. [ABSTRACT FROM AUTHOR]