scholarly journals Optimization of the adsorption of diclofenac by activated carbon and the acidic regeneration of spent activated carbon

2020 ◽  
Author(s):  
Nevim Genç ◽  
Elif Durna ◽  
Ezgi Erkişi
Keyword(s):  
Activated Carbon ◽  
Diclofenac Sodium ◽  
Operating Cost ◽  
Effective Parameter ◽  
Adsorptive Capacity ◽  
Infrared Spectrometry ◽  
Low Concentrations ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Regeneration Processes

Abstract Diclofenac sodium (DCF) is a non-steroidal anti-inflammatory drug. It has been classified as ecotoxic even at low concentrations. In this study, adsorption of DCF on coconut shell-based granular activated carbon (GAC) and regeneration of spent GAC with hydrochloric acid (HCl) were investigated. The results showed that GAC with heterogeneous surface structure adsorbs DCF endothermically with both chemical and physical forces. Adsorption and regeneration processes were optimized with Taguchi Experimental Design. The effects of all parameters affecting the adsorption and regeneration processes were determined by analysis of variance and Pareto analyses. DCF removal of 79.80% was obtained at optimum conditions and the most effective parameter was evaluated as GAC size. At optimum regeneration conditions, 6.85 mg DCF/g GAC adsorption capacity was found with an operating cost of €0.05 g GAC. The amount of HCl was the most effective parameter. It was determined that the regenerated GAC had an adsorptive capacity higher than the adsorptive capacity of the raw GAC during at least three regeneration cycles. Raw, spent and regenerated GACs were characterized by Fourier transform infrared spectrometry and scanning electron microscopy analysis.

scholarly journals Optimization of the Spent Activated Carbon Regeneration with the Radical Based Advanced Oxidation Processes: Preference of the Most Suitable Process by PROMETHEE Approach

2021 ◽  
Author(s):  
Nevim Genç ◽  
Elif Durna ◽  
Esin KACIRA
Keyword(s):  
Activated Carbon ◽  
Advanced Oxidation Processes ◽  
Operating Cost ◽  
Advanced Oxidation ◽  
Operating Conditions ◽  
Regeneration Process ◽  
Adsorptive Capacity ◽  
Optimum Conditions ◽  
Oxidation Processes ◽  
Regeneration Processes

Abstract In this study, regeneration of spent granular activated carbon (GAC) with reactive dye by hydroxyl and sulfate radical based advanced oxidation processes (Microwave (MW) + Persulfate (PS)), (Fe(II) + PS), and (O3 + H2O2) were evaluated. The adsorption of the dye to the GAC surface was characterized by chemisorption and Langmuir isotherm. Regeneration processes have been optimized by the Response Surface Methodology to determine the operating conditions that will provide the highest adsorptive capacity. The optimum conditions of (MW + PS), (Fe (II) + PS), and (O3 + H2O2) processes were (process PS anion of 45.52 g/L, pH of 11.4, MW power of 126 W, duration of 14.56 min), ( Fe (II) of 3.58 g/L, PS anion of 73.5 g/L, duration of 59.8 min, pH of 10.9) and (H2O2 of 2.8 mole/L, ozone dose of 98%, duration of 32.8 min, pH of 5.3), respectively. For (MW + PS), (Fe (II) + PS), and (O3 + H2O2) processes, the adsorptive capacity under optimum conditions were found as 4.36, 8.89 and 8.12 mg dye / g GAC respectively. For (Fe (II) + PS) and (O3 + H2O2) processes these values are approximately equal to the adsorptive capacity of raw GAC (8.01 mg dye / g GAC). The predicted values of the adsorption capacities by the obtained models were in good agreement with the actual experimental results. PROMETHEE approach was used in the preference of the appropriate regeneration process. The adsorptive capacity of regenerated GAC, operating cost of the regeneration process, change in the adsorptive capacity during the regeneration cycle and carbon mass loss criteria were taken into account. The order of preference of regeneration processes was determined as (Fe (II) + PS)> (MW + PS)> (O3 + H2O2) considering all criteria.

Study on Invalidation and Regeneration of TGV Manganese Sand Filter

2011 ◽  
Vol 233-235 ◽  
pp. 554-560
Author(s):  
Jie Zhu ◽  
Dong Zhang ◽  
Hong Bin Chen
Keyword(s):  
Physical Adsorption ◽  
Adsorptive Capacity ◽  
Manganese Ions ◽  
Sand Filter ◽  
Manganese Removal ◽  
Water Plant ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Scale Experiment ◽  
The Cost

Because the manganese removal ability of TGV manganese sand filter decreases a lot in A water plant, in this study full-scale experiment and electron microscopy analysis were conducted to evaluate the actual manganese removal ability and explore a method for regeneration in production. The results showed that the manganese sand had lost the manganese removal ability, and the principle of manganese removal was physical adsorption. The maximum adsorptive capacity was measured to be 7.2 (mg manganese ions)/ (g manganese sand) through bench scale experiments, that meant the sand filter could work effectively for 7-8 months, and then the manganese sand would become invalidate. It was recommended to dip 1 litre manganese sand in 500 ml sodium hypochlorite with 0.35% effective chlorine to achieve regeneration, and the cost was acceptable.

Material analysis techniques using the ion mill

1996 ◽  
Vol 54 ◽  
pp. 1034-1035
Author(s):  
J. P. Benedict ◽  
R. M. Anderson ◽  
S. J. Klepeis
Keyword(s):  
Polished Surface ◽  
Surface Material ◽  
Analysis Techniques ◽  
Material Analysis ◽  
Optical Inspection ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Argon Ions ◽  
The Impact ◽  
Scanning Electron

Ion mills equipped with flood guns can perform two important functions in material analysis; they can either remove material or deposit material. The ion mill holder shown in Fig. 1 is used to remove material from the polished surface of a sample for further optical inspection or SEM ( Scanning Electron Microscopy ) analysis. The sample is attached to a pohshing stud type SEM mount and placed in the ion mill holder with the polished surface of the sample pointing straight up, as shown in Fig 2. As the holder is rotating in the ion mill, Argon ions from the flood gun are directed down at the top of the sample. The impact of Argon ions against the surface of the sample causes some of the surface material to leave the sample at a material dependent, nonuniform rate. As a result, the polished surface will begin to develop topography during milling as fast sputtering materials leave behind depressions in the polished surface.

Effects of Various Antioxidant Pretreatment Modalities on Adhesion to Sound and Caries-Affected Dentin: An In Vitro Study

2021 ◽  
pp. 232020682199798
Author(s):  
Beyza Unalan Degirmenci ◽  
Alperen Degirmenci ◽  
Emine Kara
Keyword(s):  
Bond Strength ◽  
In Vitro Study ◽  
Natural Antioxidants ◽  
Microtensile Bond Strength ◽  
Mandibular Molar ◽  
Electron Microscopy Analysis ◽  
Molar Teeth ◽  
Microscopy Analysis ◽  
Two Parameters

Aim: Natural antioxidants were offered as the answer of dentin adhesion issue. The aim of this study is to investigate the effects of proanthocyanidin and lycopene as pretreatment agents on the sound and caries-affected dentin surface on microtensile bond strength and microleakage. Materials and Methods: This study was designed as in vitro because of that 84 mandibular molar teeth were collected. Forty-two of the included teeth were carious teeth, while the other 42 were without caries. Sixty of them were used for microleakage and 24 for microtensile bond strength testing and scanning electron microscopy analysis. The samples were divided into six subgroups randomly according to dentin pretreatments: 5% proanthocyanidin, 5% lycopene, and no antioxidant application. After the restorative procedures, samples were attached to the microtensile tester. Samples were subjected to tensile stress in the load cell until they broke at a speed of 0.5 mm per min. Microtensile bond strength (µTBS) and microleakage test data were analyzed with two-way analysis of variance, Bonferroni correction, and Tamhane’s T2 tests. Results: Two-way variance analysis showed that dentin pretreatment applications, dentin substrate, and the interaction between these two parameters had statistically significant effects on µTBS values ( P < .001). There was no difference between dentin pretreatment applications in terms of microleakage scores ( P > .05). Conclusion: The application of dentin pretreatment with proanthocyanidin is a successful procedure that increases the bond strength in both dentin substrate, while pretreatment with lycopene in caries-affected dentin reduces it.

scholarly journals Antiparasitic Properties of Cardiovascular Agents against Human Intravascular Parasite Schistosoma mansoni

2021 ◽  
Vol 14 (7) ◽  
pp. 686
Author(s):  
Raquel Porto ◽  
Ana C. Mengarda ◽  
Rayssa A. Cajas ◽  
Maria C. Salvadori ◽  
Fernanda S. Teixeira ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Screening Strategy ◽  
Early Infection ◽  
Global Public Health ◽  
Parasitic Worm ◽  
Electron Microscopy Analysis ◽  
Health Significance ◽  
Microscopy Analysis

The intravascular parasitic worm Schistosoma mansoni is a causative agent of schistosomiasis, a disease of great global public health significance. Praziquantel is the only drug available to treat schistosomiasis and there is an urgent demand for new anthelmintic agents. Adopting a phenotypic drug screening strategy, here, we evaluated the antiparasitic properties of 46 commercially available cardiovascular drugs against S. mansoni. From these screenings, we found that amiodarone, telmisartan, propafenone, methyldopa, and doxazosin affected the viability of schistosomes in vitro, with effective concentrations of 50% (EC50) and 90% (EC90) values ranging from 8 to 50 µM. These results were further supported by scanning electron microscopy analysis. Subsequently, the most effective drug (amiodarone) was further tested in a murine model of schistosomiasis for both early and chronic S. mansoni infections using a single oral dose of 400 mg/kg or 100 mg/kg daily for five consecutive days. Amiodarone had a low efficacy in chronic infection, with the worm and egg burden reduction ranging from 10 to 30%. In contrast, amiodarone caused a significant reduction in worm and egg burden in early infection (>50%). Comparatively, treatment with amiodarone is more effective in early infection than praziquantel, demonstrating the potential role of this cardiovascular drug as an antischistosomal agent.

scholarly journals Impact Resistance of Epoxy Composites Reinforced with Amazon Guaruman Fiber: A Brief Report

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2264
Author(s):  
Raphael H. M. Reis ◽  
Fabio C. Garcia Filho ◽  
Larissa F. Nunes ◽  
Veronica S. Candido ◽  
Alisson C. R. Silva ◽  
...  
Keyword(s):  
Fiber Composite ◽  
Impact Resistance ◽  
Fiber Composites ◽  
Epoxy Composites ◽  
Impact Performance ◽  
Electron Microscopy Analysis ◽  
Ballistic Properties ◽  
Microscopy Analysis ◽  
Izod Impact ◽  
The Impact

Fibers extracted from Amazonian plants that have traditionally been used by local communities to produce simple items such as ropes, nets, and rugs, are now recognized as promising composite reinforcements. This is the case for guaruman (Ischinosiphon körn) fiber, which was recently found to present potential mechanical and ballistic properties as 30 vol% reinforcement of epoxy composites. To complement these properties, Izod impact tests are now communicated in this brief report for similar composites with up to 30 vol% of guaruman fibers. A substantial increase in impact resistance, with over than 20 times the absorbed energy for the 30 vol% guaruman fiber composite, was obtained in comparison to neat epoxy. These results were statistically validated by Weibull analysis, ANOVA, and Tukey’s test. Scanning electron microscopy analysis disclosed the mechanisms responsible for the impact performance of the guaruman fiber composites.

scholarly journals Electron microscopy analysis of biofilms produced by Staphylococcus aureus exposed to UV-light on the surface of SnO2 thin films

2021 ◽  
Vol 27 (S1) ◽  
pp. 3168-3170
Author(s):  
Hazel Jaynelle Morales-Rodriguez ◽  
Javier Camarillo-Cisneros ◽  
María Alejandra Favila-Pérez ◽  
Alva Rocío Castillo-González ◽  
Celia María Quiñonez-Flores ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Staphylococcus Aureus ◽  
Uv Light ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Sno2 Thin Films
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