scholarly journals Adsorptive removal of azithromycin from aqueous solutions using raw and saponin-modified nano diatomite

2019 ◽  
Vol 80 (5) ◽  
pp. 939-949
Author(s):  
Siavash Davoodi ◽  
Behnaz Dahrazma ◽  
Nasser Goudarzi ◽  
Hajar Ghasemian Gorji
Keyword(s):  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Low Cost ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Low Concentrations ◽  
Intra Particle Diffusion ◽  
High Concentrations

Abstract This study aims to investigate the performance and mechanism of raw (R-ND) and saponin-modified nano diatomite (M-ND) in the removal of azithromycin from aqueous solutions. Adsorbent characterization was performed using X-ray fluorescence, Brunauer–Emmett–Teller (BET), scanning electron spectroscopy, dynamic light scattering and energy-dispersive X-ray analyses. It was shown that the specific surface area of R-ND was 119.5 m2/g, 14-fold higher than that for raw diatomite, and for M-ND it was 90.1 m2/g. Various adsorption conditions, i.e. adsorbent dosage, pH, initial concentration and contact time were investigated. According to the results, despite reducing the specific surface area by 25%, modification of nano diatomite by saponin markedly enhanced its performance in the removal of azithromycin. The maximum adsorption capacity of R-ND and M-ND in the removal of azithromycin was 68 and 91.7 mg/g, respectively. Fourier transform infrared spectroscopy results revealed that azithromycin was adsorbed by O-H groups on the diatomite surface. Weber–Morris intra-particle diffusion (IPD) model suggested that while IPD is not the rate-controlling step in high concentrations of azithromycin, it is the only step that controls the rate of adsorption in low concentrations. In comparison to R-ND, M-ND showed a higher efficiency in the removal of azithromycin and, therefore, it can be used as a promising low-cost adsorbent to remove azithromycin from aqueous solutions.

Synthesis of Novel Core-Shell Structured Hydroxyapatite/Meso-Silica for Removal of Methylene Blue from Aqueous Solutions

2012 ◽  
Vol 463-464 ◽  
pp. 543-547 ◽  
Author(s):  
Cheng Feng Li ◽  
Xiao Lu Ge ◽  
Shu Guang Liu ◽  
Fei Yu Liu
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
Precipitation Method ◽  
Core Shell ◽  
Adsorption Desorption

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.

scholarly journals Efficient Removal of Methylene Blue from Aqueous Solutions Using a High Specific Surface Area Porous Carbon Derived from Soybean Dreg

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1754
Author(s):  
Zhiwei Ying ◽  
Lu Huang ◽  
Lili Ji ◽  
He Li ◽  
Xinqi Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
Carbon Material ◽  
High Specific Surface Area ◽  
Maximum Adsorption Capacity ◽  
X Ray

Porous carbon material with high specific surface area was prepared from soybean dreg by a simple and effective two-step method (high temperature pyrolysis and activation). The structural characteristics of the synthesized carbon were evaluated by Brunauer–Emmett–Teller (BET), N2 adsorption/desorption measurements/techniques, an elemental analyzer (EA), scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), an X-ray diffractometer (XRD), Raman spectroscopy (Raman), a Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). The specific surface area of SDB-6-K was 2786 m2 g−1, the pore volume was 2.316 cm3 g−1, and the average pore size was 3.326 nm. The high specific surface area and effective functional groups of carbon material promoted the adsorption of methylene blue. The maximum adsorption capacity of SDB-6-K to methylene blue was 2636 mg g−1 at 318 K. The adsorption kinetic and isotherm data were most suitable for pseudo-second-order and Langmuir equations. The results showed that the adsorbent had excellent adsorptive ability and had good practical application potential in the field of dye wastewater treatment in the future.

scholarly journals Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić
Keyword(s):  
Chemical Modification ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Natural Zeolite ◽  
Contact Time ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

scholarly journals Nanocomposite Materials Based on Electrochemically Synthesized Graphene Polymers: Molecular Architecture Strategies for Sensor Applications

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 149
Author(s):  
André Olean-Oliveira ◽  
Gilberto A. Oliveira Brito ◽  
Celso Xavier Cardoso ◽  
Marcos F. S. Teixeira
Keyword(s):  
Conducting Polymers ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Electrochemical Sensors ◽  
Structural Characteristics ◽  
Low Cost ◽  
Large Specific Surface Area ◽  
Molecular Architecture ◽  
Sensor Applications

The use of graphene and its derivatives in the development of electrochemical sensors has been growing in recent decades. Part of this success is due to the excellent characteristics of such materials, such as good electrical and mechanical properties and a large specific surface area. The formation of composites and nanocomposites with these two materials leads to better sensing performance compared to pure graphene and conductive polymers. The increased large specific surface area of the nanocomposites and the synergistic effect between graphene and conducting polymers is responsible for this interesting result. The most widely used methodologies for the synthesis of these materials are still based on chemical routes. However, electrochemical routes have emerged and are gaining space, affording advantages such as low cost and the promising possibility of modulation of the structural characteristics of composites. As a result, application in sensor devices can lead to increased sensitivity and decreased analysis cost. Thus, this review presents the main aspects for the construction of nanomaterials based on graphene oxide and conducting polymers, as well as the recent efforts made to apply this methodology in the development of sensors and biosensors.

scholarly journals Hybrid Monolith of Graphene/TEMPO-Oxidized Cellulose Nanofiber as Mechanically Robust, Highly Functional, and Recyclable Adsorbent of Methylene Blue Dye

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Asif Hussain ◽  
Jiebing Li ◽  
Jun Wang ◽  
Fei Xue ◽  
Yundan Chen ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Specific Surface ◽  
Charge Density ◽  
Surface Charge ◽  
Surface Area ◽  
Specific Surface Area ◽  
Surface Charge Density ◽  
Cellulose Nanofibers ◽  
Maximum Adsorption Capacity ◽  
Assembly Method

Herein we demonstrate first report on fabrication, characterization, and adsorptive appraisal of graphene/cellulose nanofibers (GO/CNFs) monolith for methylene blue (MB) dye. Series of hybrid monolith (GO/CNFs) were assembled via urea assisted self-assembly method. Hybrid materials were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction patterns, Raman spectroscopy, elemental analysis, thermogravimetric curve analysis, specific surface area, surface charge density measurement, and compressional mechanical analysis. It was proposed that strong chemical interaction (mainly hydrogen bonding) was responsible for the formation of hybrid assembly. GO/CNFs monolith showed mechanically robust architecture with tunable pore structure and surface properties. GO/CNFs adsorbent could completely remove trace to moderate concentrations of MB dye and follow pseudo-second-order kinetics model. Adsorption isotherm behaviors were found in the following order: Langmuir isotherm > Freundlich isotherm > Temkin isotherm model. Maximum adsorption capacity of 227.27 mg g−1 was achieved which is much higher than reported graphene based monoliths and magnetic adsorbent. Incorporation of nanocellulose follows exponential relationship with dye uptake capacities. High surface charge density and specific surface area were main dye adsorptive mechanism. Regeneration and recycling efficiency was achieved up to four consecutive cycles with cost-effective recollection and zero recontamination of treated water.

scholarly journals Structural and Morphological Quantitative 3D Characterisation of Ammonium Nitrate Prills by X-Ray Computed Tomography

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1230
Author(s):  
Fabien Léonard ◽  
Zhen Zhang ◽  
Holger Krebs ◽  
Giovanni Bruno
Keyword(s):  
Computed Tomography ◽  
Specific Surface ◽  
Ammonium Nitrate ◽  
Surface Area ◽  
Specific Surface Area ◽  
Volume Fraction ◽  
Fuel Oil ◽  
X Ray ◽  
Oil Retention ◽  
X Ray Computed

The mixture of ammonium nitrate (AN) prills and fuel oil (FO), usually referred to as ANFO, is extensively used in the mining industry as a bulk explosive. One of the major performance predictors of ANFO mixtures is the fuel oil retention, which is itself governed by the complex pore structure of the AN prills. In this study, we present how X-ray computed tomography (XCT), and the associated advanced data processing workflow, can be used to fully characterise the structure and morphology of AN prills. We show that structural parameters such as volume fraction of the different phases and morphological parameters such as specific surface area and shape factor can be reliably extracted from the XCT data, and that there is a good agreement with the measured oil retention values. Importantly, oil retention measurements (qualifying the efficiency of ANFO as explosives) correlate well with the specific surface area determined by XCT. XCT can therefore be employed non-destructively; it can accurately evaluate and characterise porosity in ammonium nitrate prills, and even predict their efficiency.

scholarly journals Preparation of Zirconia Nanofibers by Electrospinning and Calcination with Zirconium Acetylacetonate as Precursor

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1067 ◽  
Author(s):  
Vyacheslav V. Rodaev ◽  
Svetlana S. Razlivalova ◽  
Andrey O. Zhigachev ◽  
Vladimir M. Vasyukov ◽  
Yuri I. Golovin
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Heterogeneous Catalysts ◽  
Tetragonal Zirconia ◽  
Nitrogen Adsorption ◽  
Average Diameter ◽  
High Specific Surface Area ◽  
X Ray ◽  
Adsorption Analysis

For the first time, zirconia nanofibers with an average diameter of about 75 nm have been fabricated by calcination of electrospun zirconium acetylacetonate/polyacrylonitrile fibers in the range of 500–1100 °C. Composite and ceramic filaments have been characterized by scanning electron microscopy, thermogravimetric analysis, nitrogen adsorption analysis, energy-dispersive X-ray spectroscopy, and X-ray diffractometry. The stages of the transition of zirconium acetylacetonate to zirconia have been revealed. It has been found out that a rise in calcination temperature from 500 to 1100 °C induces transformation of mesoporous tetragonal zirconia nanofibers with a high specific surface area (102.3 m2/g) to non-porous monoclinic zirconia nanofibers of almost the same diameter with a low value of specific surface area (8.3 m2/g). The tetragonal zirconia nanofibers with high specific surface area prepared at 500 °C can be considered, for instance, as promising supports for heterogeneous catalysts, enhancing their activity.

Study of Heating Effect on Specific Surface Area, and Changing Optical Properties of ZnO Nanocrystals

2011 ◽  
Vol 403-408 ◽  
pp. 1205-1210
Author(s):  
Jaleh Babak ◽  
Ashrafi Ghazaleh ◽  
Gholami Nasim ◽  
Azizian Saeid ◽  
Golbedaghi Reza ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Energy Gap ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zno Nanocrystals ◽  
Transmission Electron ◽  
Zno Nanocrystal

In this work ZnO nanocrystal powders have been synthesized by using Zinc acetate dehydrate as a precursor and sol-gel method. Then the products have been annealed at temperature of 200-1050°C, for 2 hours. The powders were characterized using X-ray diffraction (XRD), UV-vis absorption and photoluminescence (PL) spectroscopy. The morphology of refrence ZnO nanoparticles have been studied using Transmission Electron Microscope (TEM). During the annealing process, increase in nanocrystal size, defects and energy gap quantitative, and decrease in specific surface area have been observed.

Facile Preparation of Iron-Manganese Oxide@Diatomite Composite for Effective Removal of Vanadium from Wastewater

2019 ◽  
Vol 72 (9) ◽  
pp. 717
Author(s):  
Junying Song ◽  
Zhanbin Huang ◽  
Fengzhi Yang
Keyword(s):  
Specific Surface ◽  
Manganese Oxide ◽  
Surface Area ◽  
Specific Surface Area ◽  
Photoelectron Spectroscopy ◽  
Pore Volume ◽  
Low Cost ◽  
Order Kinetic ◽  
Environmental Friendliness ◽  
Iron Manganese

Excess pentavalent vanadium(v) has severely degraded water quality and posed a huge threat to human health over the past several decades. Hence, it’s urgent and significant to explore a novel adsorbent which is low cost and efficient to treat vanadium pollution. In this work, a novel iron-manganese oxide@diatomite (MnFe2O4@DE) adsorbent with superior removal performance for simulated vanadium(v) wastewater was synthesised via a facile hydrothermal method. The as-prepared MnFe2O4@DE composite was characterised through different characterisation techniques. The results indicated that the MnFe2O4 nanoparticles were uniformly deposited on the surface of diatomite, resulting in a larger specific surface area and pore volume of the composite. In addition, the MnFe2O4@DE adsorbent exhibited the highest adsorption capacity for vanadium(v) (18.37mgg−1±0.5%), which was up to around 13.24 and 1.33 times as much as that of pure diatomite and MnFe2O4, respectively. This is mainly attributed to the enhanced specific surface area and pore volume. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis demonstrated vanadium(v) could be reduced to low valence vanadium with low toxicity by the MnFe2O4@DE composite which could exist as VO2+ and VO+ cations in solution. The adsorption process was better fitted with a pseudo-second-order kinetic model and Langmuir model, which is spontaneous and endothermic. Overall, the novel MnFe2O4@DE composite could be applied as a promising adsorbent in addressing vanadium pollution issues due to its properties of low cost, effectiveness, and environmental friendliness.

scholarly journals Investigation on the adsorption of antibiotics from water by metal loaded sewage sludge biochar

2020 ◽  
Author(s):  
Xiulei Fan ◽  
Zheng Qian ◽  
Jiaqiang Liu ◽  
Nan Geng ◽  
Jun Hou ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Adsorption Process ◽  
Low Cost ◽  
Particle Diffusion ◽  
Surface Functionality ◽  
Intra Particle Diffusion ◽  
Adsorption Amount

Abstract Application of sewage sludge biochar as an adsorbent for antibiotics treatment has obtained special attention owning to their low cost and surface functionality. Three metal ions were selected to modify sewage sludge biochar through the pyrolysis with the metal loaded method. Fe loaded sewage sludge biochar (BC-Fe), Al loaded sewage sludge biochar (BC-Al) and Mn loaded sewage sludge biochar (BC-Mn) were characterized and used to explore the performance of adsorbing tetracycline (TC), sulfamethoxazole (SMZ) and amoxicillin (AMC). BC-Fe, BC-Al and BC-Mn possessed rougher surfaces, larger specific surface area and better pore structure. Intra-particle diffusion and Langmuir models were more suitable to describe the adsorption process. The maximum adsorption amount of TC, SMZ and AMC could reach 123.35, 99.01 and 109.89 mg/g by BC-Fe. Furthermore, the main mechanism of antibiotics adsorption by metal loaded sewage sludge biochars might be pores filling, Van der Waals forces and H-bonding. The study can not only solve the problems associated with the pollution of antibiotics from wastewater, but also reduced the treatment press of sewage sludge effectively.

Sign in / Sign up

Export Citation Format

Share Document