Nanopowders of Yttria-Stabilized Zirconia Doped with Rare Earth Elements as Adsorbents of Humic Acids

The aim of the investigations was to use, for the first time, zirconia nanopowders stabilized with yttria (YSZ) and rare element oxides (YSZ-Nd, YSZ-Gd) for removal of humic acids (HA) from aqueous solutions. Nanopowders were synthesized by means of hydrothermal crystallization and characterized using scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) methods and analysis of zeta potential. The adsorption processes analysis was carried out in a series of experiments depending on: initial concentration of humic acids, contact time, pH and mass of the used adsorbent. It was found, that the YSZ-Nd exhibits strong and much higher effectiveness of HA adsorption than YSZ and YSZ-Gd. The HA adsorption rate reached 96.8% for YSZ-Nd dosage of 100 mg, pH 4, and 15 min reaction time and for HA initial concentration equal to 25 mg/L. According to the Langmuir model simulation, the maximum adsorption capacity of HA on YSZ-Nd at pH 4 was calculated to be 2.95 mg/g. Changes in the FT-IR spectra of YSZ-Nd confirmed humic acids’ adsorption on the tested nanopowders, by the presence of additional bands representing carboxylic, alcohol, carbonyl and amino groups in humic acid structure. These functional groups could represent humic acids binding on the YSZ, YSZ-Nd or YSZ-Gd surfaces.

Download Full-text

Removal of Phosphorus from Wastewater by Different Morphological Alumina

Molecules ◽

10.3390/molecules25133092 ◽

2020 ◽

Vol 25 (13) ◽

pp. 3092

Author(s):

Jianchuan Sun ◽

Awang Gao ◽

Xuhui Wang ◽

Xiangyu Xu ◽

Jiaqing Song

Keyword(s):

Adsorption Capacity ◽

Maximum Adsorption Capacity ◽

X Ray Diffraction ◽

Phosphorus Adsorption ◽

X Ray ◽

Transmission Electron ◽

Ft Ir ◽

Series Of Experiments ◽

Level 1 ◽

Adsorption Desorption

In this work, an organic-free method was used to synthesize different morphological boehmite by controlling the crystallization temperature, and alumina adsorbents were obtained by baking the boehmites at 500 °C. The alumina adsorbents were characterized by X-ray diffraction (XRD), High resolution transmission electron microscope (HRTEM), Fourier transform infrared (FT-IR), N2 adsorption/desorption analysis, and their phosphorus adsorption properties were comparatively investigated by a series of experiments. The results showed that the self-prepared alumina adsorbents were lamellar and fibrous material, while the industrial adsorbent was a granular material. The lamellar alumina adsorbents had the largest specific surface area and showed better phosphorus adsorption capacity. The maximum adsorption capacity could reach up to 588.2 mg·g−1; and only 0.8 g·L−1 of lamellar alumina adsorbent is needed to treat 100 mg·L−1 phosphorus solution under the Chinese level 1 discharge standard (0.5 mg·L−1). Further investigation suggests that the lamellar alumina adsorbent kept high adsorption capacity in various solution environments.

Download Full-text

Efficient adsorption of chlorpyrifos onto modified activated carbon by gamma irradiation; a plausible adsorption mechanism

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2020-1765 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Mohamed S. Yahia ◽

Ahmed S. Elzaref ◽

Magdy B. Awad ◽

Ahmed M. Tony ◽

Ahmed S. Elfeky

Keyword(s):

Gamma Irradiation ◽

Area Measurement ◽

Maximum Adsorption Capacity ◽

X Ray Diffraction ◽

X Ray ◽

First Order ◽

Pseudo Second Order ◽

Ft Ir ◽

Pseudo First Order ◽

Kinetics Of

Abstract Commercial Granulated Active Carbon (GAC) has been modified using 10 Gy dose Gamma irradiation (GAC10 Gy) for increasing its ability of air purification. Both, the raw and treated samples were applied for removing Chlorpyrifos pesticide (CPF) from ambient midair. Physicochemical properties of the two materials were characterized by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. The phase formation and microstructure were monitored using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), supported with Energy-Dispersive X-ray (EDX). The Surface area measurement was detected using BET particle size prosometry. Obtained outcomes showed that, the maximum adsorption capacity, given by Langmuir equations, was greatly increased from 172.712 to 272.480 mg/g for GAC and GAC10 Gy, respectively, with high selectivity. The overall removal efficiency of GAC10 Gy was notably comparable to that of the original GAC-sorbent. The present study indicated that, gamma irradiation could be a promising technique for treating GAC and turned it more active in eliminating the pesticides pollutants from surrounding air. The data of equilibrium has been analyzed by Langmuir and Freundlich models, that were considerably better suited for the investigated materials than other models. The process kinetics of CPF adsorbed onto both tested carbon versions were found to obey the pseudo first order at all concentrations with an exception at 70 mg/l using GAC, where, the spontaneous exothermic adsorption of Chlorpyrifos is a strong function for the pseudo-first order (PFO) and pseudo second order (PSO) kinetics.

Download Full-text

Removal of Chromium(III) and Cadmium(II) Heavy Metal Ions from Aqueous Solutions Using Treated Date Seeds: An Eco-Friendly Method

Molecules ◽

10.3390/molecules26123718 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3718

Author(s):

Mohammad Azam ◽

Saikh Mohammad Wabaidur ◽

Mohammad Rizwan Khan ◽

Saud I. Al-Resayes ◽

Mohammad Shahidul Islam

Keyword(s):

Metal Ions ◽

Adsorption Capacity ◽

Low Cost ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

Surface Analysis Techniques ◽

Adsorption Processes ◽

Ft Ir ◽

Metal Elution ◽

Date Pits

The aim of the research was to prepare low-cost adsorbents, including raw date pits and chemically treated date pits, and to apply these materials to investigate the adsorption behavior of Cr(III) and Cd(II) ions from wastewater. The prepared materials were characterized using SEM, FT-IR and BET surface analysis techniques for investigating the surface morphology, particle size, pore size and surface functionalities of the materials. A series of adsorption processes was conducted in a batch system and optimized by investigating various parameters such as solution pH, contact time, initial metal concentrations and adsorbent dosage. The optimum pH for achieving maximum adsorption capacity was found to be approximately 7.8. The determination of metal ions was conducted using atomic adsorption spectrometry. The experimental results were fitted using isotherm Langmuir and Freundlich equations, and maximum monolayer adsorption capacities for Cr(III) and Cd(II) at 323 K were 1428.5 and 1302.0 mg/g (treated majdool date pits adsorbent) and 1228.5 and 1182.0 mg/g (treated sagai date pits adsorbent), respectively. It was found that the adsorption capacity of H2O2-treated date pits was higher than that of untreated DP. Recovery studies showed maximal metal elution with 0.1 M HCl for all the adsorbents. An 83.3–88.2% and 81.8–86.8% drop in Cr(III) and Cd(II) adsorption, respectively, were found after the five regeneration cycles. The results showed that the Langmuir model gave slightly better results than the Freundlich model for the untreated and treated date pits. Hence, the results demonstrated that the prepared materials could be a low-cost and eco-friendly choice for the remediation of Cr(III) and Cd(II) contaminants from an aqueous solution.

Download Full-text

A facile method to fabricate AC/CuO for efficient removal of organic pollutants by adsorption and persulfate-based advanced oxidation processes

Journal of Water Supply Research and Technology—AQUA ◽

10.2166/aqua.2020.094 ◽

2020 ◽

Author(s):

Youlin Li ◽

Yu Hu ◽

Wenqiao You ◽

Guangming Zhou ◽

Guilong Peng

Keyword(s):

Catalytic Performance ◽

Catalytic Degradation ◽

Maximum Adsorption Capacity ◽

Efficient Removal ◽

X Ray ◽

One Step ◽

Ft Ir ◽

Degradation Reaction ◽

The Relationship ◽

Insight Into

Abstract Activated carbon/CuO (AC/CuO) composites was prepared through a facile one-step hydrothermal method and used as a bifunctional material for adsorption and catalysis degradation of bisphenol A (BPA). The composite was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). The obtained AC/CuO exhibited excellent adsorption and catalytic performance. The maximum adsorption capacity of BPA on the AC/CuO was 319.03 mg/g according to the Langmuir fitting. At an initial BPA concentration of 20 mg/L, the BPA degradation efficiencies were maintained above 96% for 15 min by using 20 mg/L AC/CuO and 2 mM peroxymonosulfate (PMS). Moreover, the relationship between adsorption and catalytic degradation was also investigated. The results indicated that the pre-adsorption disfavored the degradation reaction. This work not only provides a novel preparation method for AC/CuO catalyst, but also gives a deeper insight into the mechanisms between adsorption and catalytic degradation.

Download Full-text

Adsorption of Hexavalent Chromium Using Banana Pseudostem Biochar and Its Mechanism

Sustainability ◽

10.3390/su10114250 ◽

2018 ◽

Vol 10 (11) ◽

pp. 4250 ◽

Cited By ~ 12

Author(s):

Shuang Xu ◽

Weiguang Yu ◽

Sen Liu ◽

Congying Xu ◽

Jihui Li ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Pyrolysis Temperature ◽

Low Cost ◽

Surface Adsorption ◽

Maximum Adsorption Capacity ◽

X Ray ◽

Adsorption Processes ◽

Different Temperatures ◽

Pseudo Second Order ◽

Porosity Analysis

A low-cost biochar was prepared through slow pyrolysis of banana pseudostem biowaste at different temperatures, and characterized by surface area and porosity analysis, scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). It was shown that the biochar prepared at low pyrolysis temperature was rich in oxygen-containing groups on the surface. Adsorption experiments revealed that the biochar prepared at 300 °C (BB300) was the best adsorbent for Cr(VI) with 125.44 mg/g maximum adsorption capacity at pH 2 and 25 °C. All the adsorption processes were well described by pseudo-second-order and Langmuir models, indicating a monolayer chemiadsorption. Furthermore, it was demonstrated that adsorption of Cr(VI) was mainly attributed to reduction of Cr(VI) to Cr(III) followed by ion exchange and complexation with the biochar.

Download Full-text

Synthesis, Characterization, and Adsorptive Properties of Fe3O4/GO Nanocomposites for Antimony Removal

Journal of Analytical Methods in Chemistry ◽

10.1155/2017/3012364 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

Xiuzhen Yang ◽

Tengzhi Zhou ◽

Bozhi Ren ◽

Zhou Shi ◽

Andrew Hursthouse

Keyword(s):

Photoelectron Spectroscopy ◽

Adsorption Process ◽

Maximum Adsorption Capacity ◽

X Ray ◽

Number Of Factors ◽

Infrared Spectrometer ◽

Pseudo Second Order ◽

Ft Ir ◽

Solid Liquid ◽

Solid Liquid Separation

A magnetic Fe3O4/GO composite with potential for rapid solid-liquid separation through a magnetic field was synthesized using GO (graphene oxide) and Fe3O4 (ferriferous oxide). Characterization of Fe3O4/GO used scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FT-IR), and Vibrating Sample Magnetometer (VSM). A number of factors such as pH and coexisting ions on adsorbent dose were tested in a series of batch experiments. The results showed that GO and Fe3O4 are strongly integrated. For pH values in the range of 3.0~9.0, the removal efficiency of Sb(III) using the synthesized Fe3O4/GO remained high (95%). The adsorption showed good fit to a pseudo-second-order and Langmiur model, with the maximum adsorption capacity of 9.59 mg/g maintained across pH 3.0–9.0. Thermodynamic parameters revealed that the adsorption process was spontaneous and endothermic. Analysis by X-ray photoelectron spectroscopy (XPS) showed that the adsorption process is accompanied by a redox reaction.

Download Full-text

Synthesis of a magnetic polystyrene-based cation-exchange resin and its utilization for the efficient removal of cadmium (II)

Water Science & Technology ◽

10.2166/wst.2018.239 ◽

2018 ◽

Vol 2017 (3) ◽

pp. 770-781 ◽

Cited By ~ 1

Author(s):

Zhaohe Wang ◽

Shilei Ding ◽

Zhixia Li ◽

Fuwei Li ◽

Tingting Zhao ◽

...

Keyword(s):

Cation Exchange ◽

Exchange Resin ◽

Cation Exchange Resin ◽

Freundlich Isotherm ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Initial Concentration ◽

Adsorption Processes ◽

Order Kinetic Model ◽

Styrene Divinylbenzene

Abstract A magnetic cation-exchange resin (MCER) was prepared by copolymerization of oleic acid-grafted magnetite with styrene, divinylbenzene (DVB), and triallylisocyanurate (TAIC) for removing Cd(II) from wastewater. A non-magnetic cation-exchange polystyrene resin (CEPR) was also prepared as a reference. Structural and morphological analyses revealed that the MCER and CEPR were mesoporous microspheres; the MCER contained about 25% Fe3O4. The influence of temperature, pH, contact time, and the initial concentration of Cd(II) on the adsorption of Cd(II) was investigated. The maximum adsorption capacity of the MCER reached 88.56 mg/g, which was achieved at 343 K using a Cd(II) initial concentration of 200 mg/L. The adsorption processes attained equilibrium within 120 min for the MCER and 300 min for the CEPR, and were well described by a pseudo-second-order kinetic model. Furthermore, the equilibrium adsorption data fitted the Freundlich isotherm model better than the Langmuir model. The superior magnetic response and regeneration of the MCER make it a good candidate as an adsorbent for removing Cd(II) from wastewater.

Download Full-text

Adsorption and Removal of Congo Red Dye from Aqueous Solution by Using Nano-Fe3O4

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.503-504.262 ◽

2012 ◽

Vol 503-504 ◽

pp. 262-265 ◽

Cited By ~ 4

Author(s):

Zhu Xing Tang ◽

Yin Chen ◽

Jun Xue ◽

Shuang Yue

Keyword(s):

Aqueous Solution ◽

Congo Red ◽

Adsorption Properties ◽

Nano Particles ◽

Maximum Adsorption Capacity ◽

X Ray ◽

Congo Red Dye ◽

Ft Ir ◽

Nano Fe3o4 ◽

Red Dye

In this paper, nano-Fe3O4 as sorbent was used to remove Congo red dye from aqueous solution, in order to investigate its adsorption properties. Fe3O4 nano-particles were synthesized by hydrothermal method, and were characterized by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Powder Diffraction (XRD) to examine their size, morphology and property. The adsorption and removal of Congo red dye from aqueous solution on nano-Fe3O4 was studied in batch equilibrium experiments. These results showed an excellent adsorption capability for Congo red with a maximum adsorption capacity of 1395mg•g-1 at 20°C and pH2.0. It indicates that Fe3O4 nano-particles can be effectively used to remove color from wastewater containing dyes.

Download Full-text

X-ray microanalysis of thin specimens in the transmission electron microscope at voltages up to 1000 Kv.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109847 ◽

1978 ◽

Vol 36 (1) ◽

pp. 540-541

Author(s):

G. Cliff ◽

M.J. Nasir ◽

G.W. Lorimer ◽

N. Ridley

Keyword(s):

Electron Microscope ◽

Transmission Electron Microscope ◽

Weight Fraction ◽

Present Series ◽

Constant Independent ◽

X Ray ◽

Transmission Electron ◽

Series Of Experiments ◽

Image Position ◽

X Ray Absorption

In a specimen which is transmission thin to 100 kV electrons - a sample in which X-ray absorption is so insignificant that it can be neglected and where fluorescence effects can generally be ignored (1,2) - a ratio of characteristic X-ray intensities, I1/I2 can be converted into a weight fraction ratio, C1/C2, using the equationwhere k12 is, at a given voltage, a constant independent of composition or thickness, k12 values can be determined experimentally from thin standards (3) or calculated (4,6). Both experimental and calculated k12 values have been obtained for K(11<Z>19),kα(Z>19) and some Lα radiation (3,6) at 100 kV. The object of the present series of experiments was to experimentally determine k12 values at voltages between 200 and 1000 kV and to compare these with calculated values.The experiments were carried out on an AEI-EM7 HVEM fitted with an energy dispersive X-ray detector.

Download Full-text

Synthesis and Evaluation of Levulinic Ester as Biodiesel Additives

Revista de Chimie ◽

10.37358/rc.20.8.8275 ◽

2020 ◽

Vol 71 (8) ◽

pp. 21-26

Author(s):

Elena-Emilia Oprescu ◽

Cristina-Emanuela Enascuta ◽

Elena Radu ◽

Vasile Lavric

Keyword(s):

Maximum Yield ◽

Strength Distribution ◽

Point Of View ◽

Reaction Parameters ◽

X Ray ◽

Ethyl Levulinate ◽

Ft Ir ◽

Ir Analysis ◽

Biodiesel Blend ◽

Acid Strength Distribution

In this study, the SO42-/TiO2-La2O3-Fe2O3 catalyst was prepared and tested in the conversion of fructose to ethyl levulinate . The catalyst was characterized from the point of view of the textural analysis, FT-IR analysis, acid strength distribution, X-ray powder diffraction and pyridine adsorption IR spectra. The influence of the reaction parameters on the ethyl levulinate yield was study. The maximum yield of 37.95% in levulinate esters was obtained at 180 �C, 2 g catalyst and 4 h reaction time. The effect of ethyl levulinate addition to diesel-biodiesel blend in different rates, i.e, 0.5, 1, 2.5, 5 (w.t %) on density, kinematic viscosity and flash point was evaluated and compared with the European specification.

Download Full-text