scholarly journals Development of Cellulose Acetate Microcapsules with Cyanex 923 for Phenol Removal from Aqueous Media

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Irma Pérez-Silva ◽  
Israel S. Ibarra ◽  
A. Castañeda-Ovando ◽  
C. A. Galán-Vidal ◽  
Ma. Elena Páez-Hernández
Keyword(s):  
Cellulose Acetate ◽  
Aqueous Media ◽  
Textile Wastewater ◽  
Phenol Removal ◽  
Batch Mode ◽  
Promising Alternative ◽  
Phenol Adsorption ◽  
Phenol Extraction ◽  
Cyanex 923 ◽  
Removal Technologies

Microcapsules of cellulose acetate with Cyanex 923 were prepared and used in this study for phenol removal from water and synthetic textile wastewater. The influence of several factors on the microcapsules extraction efficiency was studied, as well as characterization and phenol adsorption isotherm. Microcapsules characterization demonstrated the extractant reagent encapsulation, while in a batch mode procedure, good adsorption of phenol (ca. 5.5 × 10−3 mol Kg−1) has been reached. A slight decrease in phenol extraction percentage was obtained when synthetic textile wastewater was used (ca. 4.955 × 10−3 mol Kg−1), although a decrease in color was observed due to dye microcapsule extraction. Results indicate that this method is a promising alternative to conventional phenol removal technologies for aqueous samples of low phenol concentrations or in textile effluents.

Efficient trace-scale extraction method of reactor produced 199Au adequate for nuclear medicine applications

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed F. Attallah ◽  
Ahmed M. Shahr El-Din ◽  
Mohamed A. Gizawy ◽  
Amal M. I. Ali
Keyword(s):  
Aqueous Media ◽  
Selective Extraction ◽  
Extraction Process ◽  
High Yield ◽  
High Recovery ◽  
Rapid Separation ◽  
Efficient Separation ◽  
Liquid Liquid Extraction ◽  
Cyanex 302 ◽  
Cyanex 923

Abstract Production of no carrier-added (NCA) 199Au through natPt(n, γ) reaction and subsequent purification using liquid-liquid extraction from other radioisotopes is studied in the context of theranostic application. Comparative separation of NCA 199Au after dissolution of activated Pt target using three Cyanex compounds (Cyanex-272, Cyanex-302 and Cyanex-923) is evaluated. The extraction process is optimized in terms of the type of extractant, the concentration of extractant, extraction time and aqueous media (HNO3, NH4OH). Among these extractants, the Cynaex-923 is efficient and promising for rapid separation and production of NCA 199Au from HNO3 by high extraction %. Selective extraction of 199Au from other Pt and Ir radioisotopes is observed. High recovery of 199Au was obtained in the case of Cyanex-923 using 0.05 M thiourea dissolved in HCl or 2 M NaOH. Our results find the Cyanex-923 as a promising extractant for efficient separation of 199Au from irradiated Pt target with high yield (99%).

scholarly journals Functional Modification of Cellulose Acetate Microfiltration Membranes by Supercritical Solvent Impregnation

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 411
Author(s):  
Irena Zizovic ◽  
Marcin Tyrka ◽  
Konrad Matyja ◽  
Ivana Moric ◽  
Lidija Senerovic ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Ion Beam ◽  
Antibacterial Properties ◽  
Cross Flow ◽  
Batch Mode ◽  
Impregnation Process ◽  
Supercritical Solvent ◽  
Cross Flow Filtration ◽  
Microfiltration Membranes ◽  
The Impact

This study investigates the modification of commercial cellulose acetate microfiltration membranes by supercritical solvent impregnation with thymol to provide them with antibacterial properties. The impregnation process was conducted in a batch mode, and the effect of pressure and processing time on thymol loading was followed. The impact of the modification on the membrane’s microstructure was analyzed using scanning electron and ion-beam microscopy, and membranes’ functionality was tested in a cross-flow filtration system. The antibiofilm properties of the obtained materials were studied against Staphyloccocus aureus and Pseudomonas aeruginosa, while membranes’ blocking in contact with bacteria was examined for S. aureus and Escherichia coli. The results revealed a fast impregnation process with high thymol loadings achievable after just 0.5 h at 15 MPa and 20 MPa. The presence of 20% of thymol provided strong antibiofilm properties against the tested strains without affecting the membrane’s functionality. The study showed that these strong antibacterial properties could be implemented to the commercial membranes’ defined polymeric structure in a short and environmentally friendly process.

scholarly journals Removal of Chromium (VI) cation metal using Poly (N-vinyl-2-pyrrolidone)/Magnetite nanocomposite from aqueous media

2017 ◽  
Vol 13 (10) ◽  
pp. 5886-5891
Author(s):  
Padmalaya G ◽  
Sreeja BS ◽  
Radha S ◽  
Raamdheep G ◽  
Saranya J
Keyword(s):  
Magnetite Nanoparticles ◽  
Infrared Absorption Spectrum ◽  
Aqueous Media ◽  
Polyvinyl Pyrrolidone ◽  
Human Society ◽  
Promising Alternative ◽  
Chromium Vi ◽  
Ir Studies ◽  
Vis Spectroscopy ◽  
Co Precipitation

Groundwater contamination with heavy metals is considered as serious environmental hazard that affect the human society. Nano adsorbents incorporating magnetite nanoparticles provides promising alternative to facilitate removal of heavy metal ions from wastewater. The present work focuses on removal of chromium (VI) cationic metals from aqueous media using Polyvinyl Pyrrolidone (PVP)/Magnetite (Fe3O4) Nanocomposite (MNC). Magnetite nanoparticles are synthesized using chemical co-precipitation and grafted using polyvinyl pyrrolidone to form a magnetite nanocomposite. MNC were characterized with X-ray diffraction (XRD) and Infrared absorption spectrum (FT-IR) studies to affirm the formation and presence of polymeric functional groups of PVP/Magnetite nanocomposite. Batch experiments are carried out at exclusive concentration intervals to study about the adsorption efficiency of MNC on chromium (VI) cationic metal using U-Vis spectroscopy. The results obtained through adsorption studies shows the synthesized PVP/Magnetite nanocomposites has a removal efficiency of 94%.

scholarly journals Evaluation of Fixed-Bed Cultures with Immobilized Lactococcus Lactis ssp. Lactis on Different Scales

2017 ◽  
Vol 11 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Rebecca Faschian ◽  
Ilyas Eren ◽  
Steven Minden ◽  
Ralf Pörtner
Keyword(s):  
Dilution Rate ◽  
Lactococcus Lactis ◽  
Scale Up ◽  
Fixed Bed ◽  
Pilot Scale ◽  
Fixed Bed Reactor ◽  
Batch Mode ◽  
Promising Alternative ◽  
Fixed Beds ◽  
Pilot Scale Reactor

Fixed-bed processes, where cells are immobilized within macroporous carriers, are a promising alternative to processes with suspended cells. A scale-up concept is presented in order to evaluate the performance as part of process design of fixed-bed processes. Therefore,Lactococcus lactiscultivation in chemostat and batch mode was compared to fixed bed cultures on three different scales, the smallest being the downscaledMultifermwith 10 mL fixed bed units, the second a 100 mL fixed-bed reactor and the third a pilot scale reactor with 1 L fixed bed volume. As expected, the volume specific lactate productivity of all cultivations was dependent on dilution rate. In suspension chemostat culture a maximum of 2.3 g·L-1·h-1was reached. Due to cell retention in the fixed-beds, productivity increased up to 8.29 g·L-1·h-1at a dilution rate of D = 1.16 h-1(corresponding to 2.4·µmax) on pilot scale. For all fixed bed cultures a common spline was obtained indicating a good scale-up performance.

Cellulose acetate/poly(vinyl alcohol) hybrid fibrous mat containing tetracycline hydrochloride and phenytoin sodium: Morphology, drug release, antibacterial, and cell culture studies

2018 ◽  
Vol 33 (6) ◽  
pp. 597-611 ◽  
Author(s):  
Hamed Souriyan-Reyhani pour ◽  
Ramin Khajavi ◽  
Mohammad Esmaeil Yazdanshenas ◽  
Payam Zahedi ◽  
Mohammad Mirjalili
Keyword(s):  
Drug Release ◽  
Cellulose Acetate ◽  
Vinyl Alcohol ◽  
Aqueous Media ◽  
Tetracycline Hydrochloride ◽  
Diameter Distribution ◽  
Poly Vinyl Alcohol ◽  
Release Kinetic ◽  
Phenytoin Sodium ◽  
20 Nm

The objective of this study was to introduce an electrospun hybrid fibrous mat (a dual-fiber drug delivery system) based on cellulose acetate and poly(vinyl alcohol) containing tetracycline hydrochloride and phenytoin sodium, respectively. Characterization of samples was carried by morphology, drug release, cell cytotoxicity, adhesion, antibacterial property, and wettability investigations. The results showed a uniform shape and a narrow diameter distribution of fibers (between 160 ± 20 nm) for fabricated cellulose acetate/poly(vinyl alcohol) hybrid fibrous mat. The tetracycline hydrochloride release from cellulose acetate significantly decreased due to gel formation of poly(vinyl alcohol) in aqueous media. The best fit for drug release kinetic of hybrid sample was Higuchi model. Sample with tetracycline hydrochloride and phenytoin sodium drugs showed improved cell growth, viability, and antibacterial activity against Escherichia coli (~89%) and Staphylococcus aureus (~98%) in comparison with sample without drugs. The hydrophilic property of cellulose acetate/poly(vinyl alcohol) fibrous sample containing the drugs was also remarkable (~45°). To consider the obtained results, the presented hybrid fibrous mat shows a high potent for biomedical applications.

Granular activated algae for wastewater treatment

2015 ◽  
Vol 71 (6) ◽  
pp. 832-839 ◽  
Author(s):  
O. Tiron ◽  
C. Bumbac ◽  
I. V. Patroescu ◽  
V. R. Badescu ◽  
C. Postolache
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Transformation Rate ◽  
Batch Mode ◽  
Promising Alternative ◽  
Ph Variation ◽  
Microalgae Harvesting ◽  
Cost Efficient

The study used activated algae granules for low-strength wastewater treatment in sequential batch mode. Each treatment cycle was conducted within 24 h in a bioreactor exposed to 235 μmol/m2/s light intensity. Wastewater treatment was performed mostly in aerobic conditions, oxygen being provided by microalgae. High removal efficiency of chemical oxygen demand (COD) was achieved (86–98%) in the first hours of the reaction phase, during which the indicator's removal rate was 17.4 ± 3.9 mg O2/g h; NH4+ was removed during organic matter degradation processes with a rate of 1.8 ± 0.6 mg/g h. After almost complete COD removal, the NH4+ remaining in the liquor was removed through nitrification processes promoted by the increase of the liquor's oxygen saturation (O2%), the transformation rate of NH4+ into NO3− increasing from 0.14 ± 0.05 to 1.5 ± 0.4 mg NH4+/g h, along with an O2% increase. A wide removal efficiency was achieved in the case of PO43– (11–85%), with the indicator's removal rate being 1.3 ± 0.7 mg/g h. In the provided optimum conditions, the occurrence of the denitrifying activity was also noticed. A large pH variation was registered (5–8.5) during treatment cycles. The granular activated algae system proved to be a promising alternative for wastewater treatment as it also sustains cost-efficient microalgae harvesting, with microalgae recovery efficiency ranging between 99.85 and 99.99% after granules settling with a velocity of 19 ± 3.6 m/h.

Adsorption of Phenol in Wastewater Using Nano Grapheme Oxide-Chitosan-Bentonite Absorbent

2020 ◽  
Vol 11 (4) ◽  
pp. 368-380
Author(s):  
Alireza Jadid ◽  
Shadab Shahsavari ◽  
Aliakbar Seifkordi ◽  
Ali Vaziri Yazdi
Keyword(s):  
Graphene Oxide ◽  
Adsorption Process ◽  
Removal Rate ◽  
Physical Adsorption ◽  
Phenol Removal ◽  
Phenol Adsorption ◽  
Absorption Isotherm ◽  
Optimum Formulation ◽  
Nano Graphene ◽  
Kinetics Of

Background and Objectives: Contamination of surface and groundwater sources with aromatic compounds such as phenolic compounds is one of the newest environmental problems that humans encountered it today. One of the ways to remove these pollutants is the use of polymeric adsorbents. In this study, chitosan-bentonite-nano-graphene oxide nanosorbent was synthesized to investigate the phenol adsorption. Material and Methods: In this research, experimental design was performed using Design-Expert 7.0 software to investigate the effect of independent variables including nano graphene oxide, chitosan and bentonite on the dependent variable (phenol removal rate). Moreover, phenol absorption isotherm, kinetics and thermodynamics, were also examined. Results: Eventually, the optimum formulation of nano-adsorbent with specifications of 0.1 g of chitosan, 0.18 g of bentonite and 0.07 g of nano-graphene oxide was investigated. Optimal adsorption conditions were also obtained at a concentration of 100 ppm, pH=5 and 45 minutes of absorption time. Conclusion: Finally, it was found that the synthesized nanosorbent follows the Langmuir isotherm, which represents physical adsorption, and also the kinetics of the adsorption process is the diffusion between particles. As a result, it was found that the optimal application of this nano-adsrbent is in wastewaters with a temperature of less than 400 °C.

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