scholarly journals Removal of Cesium from Radioactive Waste Liquids Using Geomaterials

2021 ◽  
Vol 11 (18) ◽  
pp. 8407
Author(s):  
Haixin Zhang ◽  
Mingze Zhu ◽  
Xiaoyu Du ◽  
Sihan Feng ◽  
Naoto Miyamoto ◽  
...  
Keyword(s):  
Fly Ash ◽  
Radioactive Waste ◽  
Adsorption Capacity ◽  
Raw Materials ◽  
Energy Dispersive Spectrometer ◽  
Bet Surface Area ◽  
Size Analysis ◽  
Experimental Conditions ◽  
Pore Size Analysis ◽  
Contaminated Waste

In this study, we investigated the removal of Cs from aqueous solutions using geomaterials. Adsorption was chosen as an effective method to develop for the removal of Cs from radioactive waste liquids. Geomaterials, including fly ash and slag as raw materials, were prepared as adsorbents using an alkali activator. The materials were characterized by X-ray diffraction (XRD); scanning electron microscopy with energy dispersive spectrometer (SEM-EDS); and BET surface area, pore volume, and pore size analysis. The effects of various parameters, such as pH, contact time, and adsorbent dosage on the adsorption of the Cs were studied. The partition coefficient (PC) as well as the adsorption capacity were evaluated to assess the true performance of the adsorbent in this work. The fly ash-based geomaterials showed a maximum Cs adsorption capacity of 89.32 mg·g−1 and a high PC of 31.02 mg·g−1·mM−1 for the Cs under our experimental conditions. From this work, this method can be regarded being practical for use as a potential adsorbent for treating Cs in wastewater. Furthermore, the immobilization of Cs in geomaterials was explored from a chemical perspective. In conclusion, fly ash-based geomaterials may be a promising option for the treatment and disposal of nuclear-contaminated waste.

Adsorption characteristics of benzene on biosolid adsorbent

2003 ◽  
Vol 47 (1) ◽  
pp. 83-87
Author(s):  
C. Hung-Lung ◽  
T.-C. Chen ◽  
M.-C. Tsai ◽  
Y.-L. Chen
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Pore Diameter ◽  
Treatment Plant ◽  
Raw Material ◽  
Bet Surface Area ◽  
Size Analysis ◽  
Average Pore ◽  
Pore Size Analysis ◽  
Different Temperatures

This study selected biosolids from a petrochemical wastewater treatment plant as the raw material. The sludge was immersed in 0 to 5 mol l-1 of ZnCl2 solutions and pyrolyzed at different temperatures. When the sludge was pyrolyzed for 30 min at temperatures of 400, 500, 600, and 700°C, the corresponding surface area of the biosolid adsorbent was 46, 401, 921, and 727 m2/g, respectively. Pore size analysis indicated that the mesopore (20 to 500 Å) contributed more than the macropore and micropore in the sludge pyrolytic residue. When the benzene influent concentration was 800 ppmv, the adsorption capacity ranged from 59 to 164 mg/g for different biosolid adsorbents. A larger BET surface area and smaller average pore diameter yielded a larger benzene adsorption capacity.

scholarly journals Fly Ash Coated with Magnetic Materials: Improved Adsorbent for Cu (II) Removal from Wastewater

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 63
Author(s):  
Maria Harja ◽  
Gabriela Buema ◽  
Nicoleta Lupu ◽  
Horia Chiriac ◽  
Dumitru Daniel Herea ◽  
...  
Keyword(s):  
Fly Ash ◽  
Adsorption Capacity ◽  
Copper Ions ◽  
Synthetic Wastewater ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Copper Adsorption ◽  
X Ray

Fly ash/magnetite material was used for the adsorption of copper ions from synthetic wastewater. The obtained material was characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area, and vibrating sample magnetometer (VSM). Batch adsorption experiments were employed in order to investigate the effects of adsorbent dose, initial Cu (II) concentration and contact time over adsorption efficiency. The experimental isotherms were modeled using Langmuir (four types of its linearization), Freundlich, Temkin, and Harkins–Jura isotherm models. The fits of the results are estimated according to the Langmuir isotherm, with a maximum adsorption capacity of 17.39 mg/g. The pseudo-second-order model was able to describe kinetic results. The data obtained throughout the study prove that this novel material represents a potential low-cost adsorbent for copper adsorption with improved adsorption capacity and magnetic separation capability compared with raw fly ash.

Preparation of lignin-based mesoporous biochar nano- and microparticles, and their adsorption properties for hexavalent chromium

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6363-6377
Author(s):  
Yu Hu ◽  
Meng Ling ◽  
Xianfa Li
Keyword(s):  
Adsorption Capacity ◽  
Functional Groups ◽  
Pyrolysis Temperature ◽  
Waste Water Treatment ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Contaminated Waste ◽  
Mesoporous Biochar

The removal performance and mechanism of Cr(VI) from aqueous solution was studied for a novel micro-nano particle kraft lignin biochar (BC) pyrolyzed at 400 to 700 °C. The physicochemical properties of BC were determined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption-desorption isotherms. The results illustrated that the BC had irregular micro- and nanoparticles with abundant pore structure and high BET surface area (111.1 m2/g). The FT-IR results showed that the lower pyrolysis temperature resulted in more oxygen-containing functional groups. The Cr(VI) adsorption capacity decreased with the pyrolysis temperature increasing from 400 to 700 °C, and the maximum percentage removal of Cr(VI) for BC obtained at 400 °C was 100% at pH 2, which suggested that the removal efficiency was mainly dependent on functional groups. Kinetic analysis demonstrated that Cr(VI) adsorption on BC fit well to the pseudo-second-order kinetic model. The adsorption data was well fitted with the Langmuir isotherm models, and the maximum adsorption capacity was 37.2 mg/g at 298K. The BC could be reused twice with Cr(VI) removal of 63.91% and was suitable for Cr(VI) contaminated waste-water treatment.

Preparation of Mullite Nanocomposites Powders from Coal Fly Ash via Hydrothermal Crystallization

2011 ◽  
Vol 250-253 ◽  
pp. 3313-3319 ◽  
Author(s):  
Lin Xin Tong ◽  
Jin Hong Li ◽  
Jie Shen ◽  
Xiao Qian Jiang
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Mas Nmr ◽  
Bet Surface Area ◽  
Growth Unit ◽  
Size Analysis ◽  
Powder Size ◽  
Hydrothermal Crystallization ◽  
Tem Analysis ◽  
X Ray

Mullite nanocomposites powders have been successfully synthesized from high-aluminium coal fly ash via hydrothermal crystallization process. The mullite nanocomposites powders are investigated and charactered by laser particle size analysis, BET surface area analysis, X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) analysis, selected area electron diffraction (SAED) analysis and energy-dispersive X-ray (EDX) analysis. Moreover, the reaction mechanism is speculated according to MAS-NMR results. The experimental results show that mullite nanocomposites powders can be prepared at 80-90 °C for 3 h with NaOH concentration of 2-4 mol/L and L/S ratio (liquid/solid ratio in mass) of 10 mL/g. The powder size of D50is about 1.88-3.27 mm. Mullite nanocomposites are mainly rod-like, acicular and fibroid in shape with an range of 30-80 nm in length and an range of 4.5-30 nm in diameter. MAS-NMR analysis indicates that the nano-size mullite grow around the central atom-Al, Si of [AlSi]O4tetrahedral and the growth unit Al[OH]4-is existed in this process definitely.

Synthesis of Hydroxyapatite in Microemulsion and its Adsorption Properties for Human Serum Albumin

2009 ◽  
Vol 79-82 ◽  
pp. 51-54
Author(s):  
Xian Peng Zheng ◽  
Yan Liu ◽  
Yan Ming Yang ◽  
Dong Wei ◽  
Yuan Yuan Xu ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Adsorption Capacity ◽  
Serum Protein ◽  
Ph Value ◽  
Energy Dispersive Spectrometer ◽  
High Surface ◽  
Size Analysis ◽  
Human Serum Protein

Hydroxyapatite (HAP) was synthesized in Triton X-100 microemulsion and was characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS). Particle size analysis results showed that the particles has nanometer size, high surface area and loose structure. The prepared HAP had high adsorption capacity to human serum protein and the adsorption of human serum protein on the surface of HAP was confirmed by SEM. The factors which influenced the adsorption capacity such as the acidity, reaction time and the concentration of adsorbent were investigated in detail and the adsorption isothermal was also obtained. The adsorption capacity reduced while the pH value increased, and the adsorption reached equilibrium when shaking time was up to 40 min. The adsorption isotherm could be fitted by the pseudo-Langmuir type. The adsorption of human serum albumin on HAP was investigated, and the influences of adsorption on the conformation of human serum albumin were studied by infrared and ultraviolet spectroscopy. It can be seen from the FT-IR spectra that the intensity of flex vibration of C=O, N-C bonds all weakened. The calculation results of ultraviolet spectrum indicated that the quantity of α spiral structure reduced from 44% to 17.12%.

scholarly journals EFFECT OF THE CARBONIZATION AND ACTIVATION PROCESS ON THE ADSORPTION CAPACITY OF RICE HUSK ACTIVATED CARBON

2017 ◽  
Vol 55 (4) ◽  
pp. 494 ◽  
Author(s):  
Hoa Thai Ma ◽  
Hung Cam Ly ◽  
Van Thi Thanh Ho ◽  
Nguyen Bao Pham ◽  
Dat Chi Nguyen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Rice Husk ◽  
Raw Materials ◽  
Internal Surface ◽  
Surface Characteristics ◽  
Bet Surface Area ◽  
Adsorptive Capacity ◽  
Physical Activation ◽  
Activation Process

In this study, rice husk was used as a precursor to prepare activated carbon using steam as a physical activation agent. Steam for activation can be used to activate almost all raw materials. A variety of methods have been developed but all of these share the same basic principle of initial carbonization followed by an activation step with steam. The study also investigates the effects of preparation parameters on the surface characteristics of the carbon. These parameters include the range of temperature and time in the carbonization and activation. The initial carbonization, done at temperatures up to 500°C in 60 min, is a highly exothermic process where the temperature is strictly controlled. The creation of the internal surface is done during the activation step with steam at temperatures 800°C in 30 min., for which the BET surface area is up to 710.8m2/g. Besides, the iodine and methylene blue adsorption capacity of rice-husk carbon are the best that reach 865.98±6.5 and 217.86±1.0 (mg/g), respectively. The entire synthetic procedure was simple, environmental-friendly and economical-effectively. The application prospect of the activated carbon prepared in this work was much more promising due to its high adsorptive capacity.

scholarly journals Adsorption Performance of Modified Fly Ash for Copper Ion Removal from Aqueous Solution

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 207
Author(s):  
Gabriela Buema ◽  
Maria Harja ◽  
Nicoleta Lupu ◽  
Horia Chiriac ◽  
Loredana Forminte ◽  
...  
Keyword(s):  
Fly Ash ◽  
Adsorption Capacity ◽  
Copper Ions ◽  
Alkali Treatment ◽  
Copper Ion ◽  
Ion Concentration ◽  
Bet Surface Area ◽  
X Ray ◽  
Ion Removal ◽  
New Material

The initial characteristics of Romanian fly ash from the CET II Holboca power plant show the feasibility of its application for the production of a new material with applicability in environmental decontamination. The material obtained was characterized using standard techniques: scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), instrumental neutron activation analysis (INAA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), the Brunauer–Emmett–Teller (BET) surface area, and thermogravimetric differential thermal analysis (TG-DTA). The adsorption capacity of the obtained material was evaluated in batch systems with different values of the initial Cu(II) ion concentration, pH, adsorbent dose, and contact time in order to optimize the adsorption process. According to the experimental data presented in this study, the adsorbent synthesized has a high adsorption capacity for copper ions (qmax = 27.32–58.48 mg/g). The alkali treatment of fly ash with NaOH improved the adsorption capacity of the obtained material compared to that of the untreated fly ash. Based on the kinetics results, the adsorption of copper ions onto synthesized material indicated the chemisorption mechanism. Notably, fly ash can be considered an important beginning in obtaining new materials with applicability to wastewater treatment.

Simple and efficient ion imprinted polymer for recovery of uranium from environmental samples

2012 ◽  
Vol 65 (4) ◽  
pp. 728-736 ◽  
Author(s):  
V. E. Pakade ◽  
E. M. Cukrowska ◽  
J. Darkwa ◽  
G. Darko ◽  
N. Torto ◽  
...  
Keyword(s):  
Contact Time ◽  
Uranyl Ion ◽  
Bet Surface Area ◽  
Size Analysis ◽  
Ion Imprinted Polymer ◽  
Imprinted Polymer ◽  
Solution Ph ◽  
Retention Capacity ◽  
Pore Size Analysis ◽  
Ion Imprinted

Ion imprinted polymer material (IIP) was prepared by forming ternary complexes of uranyl imprint ion with 1-(prop-2-en-1-yl)-4-(pyridin-2-ylmethyl)piperazine and methacrylic acid followed by thermal copolymerization with ethylene glycol dimethacrylate as the cross-linking monomer in the presence of 1,1′-azobis(cyclohexanecarbonitrile) initiator and 2-methoxy ethanol porogenic solvent. HCl solution (5 mol/L) was used to leach out the uranyl template ion from the IIP particles. Similarly, the control polymer (CP) material was also prepared exactly under the same conditions as the IIP but without the uranyl ion template. Various parameters such as solution pH, initial concentration, aqueous phase volume, sorbent dosage, contact time and leaching solution volumes were investigated. SEM, IR and BET-surface area and pore size analysis were used for the characterization of IIP and CP materials. The extraction efficiency of the IIP and CP was compared using a batch and SPE mode of extraction. The optimal pH for quantitative removal is 4.0–8.0, sorbent amount is 20 mg, contact time is 20 min and the retention capacity is 120 mg of uranyl ion per g of IIP. The IIP prepared demonstrated superior selectivity towards coexisting cations and therefore it can be used for selective removal of uranium from complex matrices.

In Vitro Compatibility of Hydroxyapatite Nanoparticles (HAp-NPs) for Restoration Purposes of Archaeological Lime-Based Plasters

2019 ◽  
Vol 60 ◽  
pp. 162-173
Author(s):  
Hussein Marey Mahmoud
Keyword(s):  
Calcium Nitrate ◽  
Ammonium Hydroxide ◽  
Experimental Tests ◽  
Bet Surface Area ◽  
Size Analysis ◽  
Hydroxyapatite Nanoparticles ◽  
Pore Size Analysis ◽  
The Stability ◽  
Present Trial

For a number of years, nanomaterials have been considered as a perfect solution to maintain the stability of different cultural heritage materials. In the present trial, hydroxyapatite nanoparticles (HAp-NPs) have been synthesized via the wet chemical reaction of calcium nitrate and ammonium hydroxide. Then, the possible efficiency of HAp-nanoparticles was evaluated to improve restoration formulas for some archaeological lime-based plasters. A broad series of analytical methods, namely OM, FE-SEM, TEM, AFM, XRD and BET surface area-pore size analysis, was selected for characterizing the archaeological samples and to rate the experimental tests. Further, the physical-mechanical behavior of samples was measured. The emulated modifications induced by the HAp-NPs treatment have been evaluated and discussed.

IDENTIFICATION OF ABNORMAL PHASE AND ITS FORMATION MECHANISM IN SYNTHESIZING CHALCOGENIDE FILMS

2016 ◽  
Vol 23 (01) ◽  
pp. 1550081 ◽  
Author(s):  
KEGAO LIU ◽  
NIANJING JI ◽  
YONG XU ◽  
HONG LIU
Keyword(s):  
Raw Materials ◽  
Water Immersion ◽  
Energy Dispersive Spectrometer ◽  
Soda Lime ◽  
Preferred Orientation ◽  
Water Soluble ◽  
Soda Lime Glass ◽  
Photoelectric Conversion ◽  
Experimental Conditions ◽  
Chalcogenide Films

Chalcogenide films can be used in thin-film solar cells due to their high photoelectric conversion efficiencies. It was difficult to identify one abnormal phase with high X-ray diffraction (XRD) intensity and preferred orientation in the samples for preparing chalcogenide films by spin-coating and co-reduction on soda-lime glass ([Formula: see text]) substrates. The raw materials and reductant are metal chlorides and hydrazine hydrate respectively. In order to identify this phase, a series of experiments were done under different conditions. The phases of obtained products were analyzed by XRD and the size and morphology were characterized by scanning electron microscope (SEM) and atomic force microscopy (AFM). From the experimental results, first it was proved that the abnormal phase was water-soluble by water immersion experiment, then it was identified as NaCl crystal through XRD, energy dispersive spectrometer (EDS) and SEM. The cubic NaCl crystals have high crystallinity with size lengths of about 0.5–2[Formula: see text][Formula: see text]m and show a [Formula: see text]100[Formula: see text] preferred orientation. The reaction mechanism of NaCl crystal was proposed as follows: The NaCl crystal was formed by reaction of Na2O and HCl in a certain experimental conditions.

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