scholarly journals A Biosorption-Pyrolysis Process for Removal of Pb from Aqueous Solution and Subsequent Immobilization of Pb in the Char

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2381
Author(s):  
Yue Wang ◽  
Jinhong Lü ◽  
Dongqing Feng ◽  
Sen Guo ◽  
Jianfa Li
Keyword(s):  
Heavy Metals ◽  
Pyrolysis Temperature ◽  
Acidic Solution ◽  
Potential Solution ◽  
Pyrolysis Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Pretreated Biomass ◽  
Pb Immobilization

The application of biosorption in the removal of heavy metals from water faces a challenge of safe disposal of contaminated biomass. In this study, a potential solution for this problem was proposed by using a biosorption-pyrolysis process featured by pretreatment of biomass with phosphoric acid (PA). The PA pretreatment of biomass increased the removal efficiency of heavy metal Pb from water by sorption, and subsequent pyrolysis helped immobilize Pb in the residual char. The results indicate that most (>95%) of the Pb adsorbed by the PA-pretreated biomass was retained in the char, and that the lower pyrolysis temperature (350 °C) is more favorable for Pb immobilization. In this way, the bioavailable Pb in the char was hardly detected, while the Pb leachable in acidic solution decreased to <3% of total Pb in the char. However, higher pyrolysis temperature (450 °C) is unfavorable for Pb immobilization, as both the leachable and bioavailable Pb increased to >28%. The reason should be related to the formation of elemental Pb and unstable Pb compounds during pyrolysis at 450 °C, according to the X-ray diffraction study.

Removal of Heavy Metals from Aqueous Solution by Hydroxyapatite/Chitosan Composite

2013 ◽  
Vol 789 ◽  
pp. 176-179 ◽  
Author(s):  
Eny Kusrini ◽  
Nofrijon Sofyan ◽  
Dwi Marta Nurjaya ◽  
Santoso Santoso ◽  
Dewi Tristantini
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Metal Ions ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Sem Micrograph ◽  
Pseudo Second Order ◽  
Chitosan Composite

Hydroxyapatite/chitosan (HApC) composite has been prepared by precipitation method and used for removal of heavy metals (Cr6+, Zn2+and Cd2+) from aqueous solution. The HAp and 3H7C composite with HAp:chitosan ratio of 3:7 (wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray spectroscopy. The SEM results showed that HAp is spherical-shaped and crystalline, while chitosan has a flat structure. SEM micrograph of 3H7C composite reveals crystalline of HAp uniformly spread over the surface of chitosan. The crystal structure of HAp is maintained in 3H7C composite. Chitosan affects the adsorption capacity of HAp for heavy metal ions; it binds the metal ions as well as HAp. The kinetic data was best described by the pseudo-second order. Surface adsorption and intraparticle diffusion take place in the mechanism of adsorption process. The binding of HAp powder with chitosan made the capability of composite to removal of Cr6+, Zn2+and Cd2+from aqueous solution effective. The order of removal efficiency (Cr6+> Cd2+> Zn2+) was observed.

scholarly journals Conversion of fisheries waste as magnetic hydroxyapatite bionanocomposite for the removal of heavy metals from groundwater

2017 ◽  
Vol 18 (4) ◽  
pp. 1406-1419
Author(s):  
F. Elmi ◽  
R. Chenarian Nakhaei ◽  
H. Alinezhad
Keyword(s):  
Heavy Metals ◽  
Freundlich Isotherm ◽  
Spectroscopic Techniques ◽  
Order Kinetic ◽  
Fish Scale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Order Kinetic Model ◽  
Ir Spectroscopic

Abstract This study is the first report of its type demonstrating the synthesis of mHAP on the basis of magnetic functionalization with nHAP, which were synthesized using Rutilus frisii kutum fish scale as a benign fishery waste by-product. The mHAP was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray diffraction (EDX), and Fourier transform infrared (FT-IR) spectroscopic techniques. The XRD pattern confirmed the formation of a single-phase nHAP without any extra steady phases. It was also found that the pseudo-second-order kinetic model gave a satisfactory fit to the experimental data (R2 = 0.99). The maximum removal percentages of Cu and Zn ions in optimal conditions (adsorbent dosage at 0.1 g, 30 min contact time at 25 ± 1 °C and pH = 5 ± 0.1) by mHAP were 97.1% and 93.8%, respectively. Results also demonstrated that mHAP could be recycled for up to five cycles in the case of copper and zinc. The Langmuir isotherm was proved to have a better correlation compared with that of the Freundlich isotherm. The thermodynamic parameters indicated that it was a spontaneously endothermic reaction. In conclusion, mHAP could be regarded as a powerful candidate for efficient biosorbent, capable of adsorbing heavy metals from aqueous solutions.

Coordination of Lead (II) and Cadmium (II) Ions to Nylon 6/flax Linum Composite as a Route of Removal of Heavy Metals

2021 ◽  
Author(s):  
NT Moja ◽  
SB Mishra ◽  
SS Hwang ◽  
TY Tsai ◽  
Ajay Kumar Mishra
Keyword(s):  
Heavy Metals ◽  
Cell Size ◽  
Nylon 6 ◽  
Injection Technique ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Langmuir Isotherm Model ◽  
Thermographic Analysis ◽  
Emission Microscopy

Abstract Nylon 6 (PA6) reinforced Flax Linum composites were synthesized by melt mix extrusion and molded through Mucell\ ® injection technique for adsorption application for removal of Cd(II) and Pb(II) metal ions. The structural morphologies of all samples were evaluated using X-ray diffraction (XRD), Transmittance emission microscopy (TEM) and Scanning emission microscopy (SEM), indicating crystallized materials with pore-like cells and Thermographic analysis (TGA) illustrated the thermally stable., Microscopic PA6 revealed the effects of Flax content on both cell density and cell size of the foamed samples. The cell size of neat PA6 (48 μm) changed to 36, 17, and 15 μm after incorporation of Flax compositions for 1.0, 3.0 and 5.0 wt%. The removal of Cd(II)and Pb(II) with PA6/Flax 1.0 wt% composite was found to follow the Langmuir isotherm model. The results indicated that PA6 1.0 wt% composite can be efficiently used as a superabsorbent for the removal of Cd(II) and Pb(II) from aqueous solution.

scholarly journals Heavy metals removal by thiol modified oak charcoal: Adsorption efficiency and selectivity

2021 ◽  
Vol 10 (3) ◽  
pp. 227
Author(s):  
Zeinab Ezzeddine ◽  
Batoul Solh ◽  
Hussein Hamad
Keyword(s):  
Heavy Metals ◽  
Metal Ions ◽  
Adsorption Efficiency ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Capacities ◽  
Metals Removal ◽  
Granulometric Analysis ◽  
Adsorbent Surface ◽  
Removal Of Heavy Metals

<p>Herein, the removal of heavy metals on thiol modified oak charcoal was investigated. The modified charcoal was characterized by X-ray diffraction, granulometric analysis and infrared spectroscopy. Then, its adsorption efficiency for the removal of Cd2+, Cu2+ and Pb2+ from water was tested. The effects of several conditions on metals adsorption were investigated such as contact time, pH, electrolytes and the initial metal ions concentration. The adsorption capacities were high (197, 250 and 214 mg g-1 for Cd2+, Pb2+ and Cu2+ respectively). The selectivity was also dependent on the metal ions nature and the functional group used. The mechanism of adsorption is complex where several types of interaction between metal ions and the adsorbent surface are involved.</p>

scholarly journals Synthesis and Characterization of Iron Oxide Nanoparticles and Applications in the Removal of Heavy Metals from Industrial Wastewater

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Zuolian Cheng ◽  
Annie Lai Kuan Tan ◽  
Yong Tao ◽  
Dan Shan ◽  
Kok Eng Ting ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Industrial Wastewater ◽  
Maghemite Nanoparticles ◽  
X Ray Diffraction ◽  
Toxic Heavy Metals ◽  
Solution Ph ◽  
X Ray ◽  
Adsorption Data ◽  
Removal Of Heavy Metals

This study investigated the applicability of maghemite (γ-Fe2O3) nanoparticles for the selective removal of toxic heavy metals from electroplating wastewater. The maghemite nanoparticles of 60 nm were synthesized using a coprecipitation method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX). Batch experiments were carried out for the removal of Pb2+ions from aqueous solutions by maghemite nanoparticles. The effects of contact time, initial concentration of Pb2+ions, solution pH, and salinity on the amount of Pb2+removed were investigated. The adsorption process was found to be highly pH dependent, which made the nanoparticles selectively adsorb this metal from wastewater. The adsorption of Pb2+reached equilibrium rapidly within 15 min and the adsorption data were well fitted with the Langmuir isotherm.

scholarly journals Evaluation of Hydrogen Yield Evolution in Gaseous Fraction and Biochar Structure Resulting from Walnut Shells Pyrolysis

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6359
Author(s):  
Elena David
Keyword(s):  
Heating Rate ◽  
Pyrolysis Temperature ◽  
Walnut Shell ◽  
Hydrogen Yield ◽  
X Ray Diffraction ◽  
Fast Heating ◽  
X Ray ◽  
Walnut Shells ◽  
Water Vapors ◽  
Gaseous Fraction

Conversion experiments of wet and dry walnut shells were performed, the influence of moisture content on the hydrogen yield in the gas fraction was estimated and the resulted biochar structure was presented. Measurements of the biochar structures were performed using X-ray diffraction and scanning electron microscopy methods. The results demonstrate that heating rate played a key role in the pyrolysis process and influenced the biochar structure. Under fast heating rate, the interactions between the water vapors released and other intermediate products, such as biochar was enhanced and consequently more hydrogen was generated. It could also be observed that both biochar samples, obtained from wet and dry walnut shells, had an approximately smooth surface and are different from the rough surface of the raw walnut shell, but there are not obvious differences in shape and pores structure between the two biochar samples. The increasing of the biochar surface area versus pyrolysis temperature is due tothe formation of micropores in structure. The biochar shows a surface morphology in the form of particles with rough, compact and porous structure. In addition the biochar structure confirmed that directly pyrolysis of wet walnut shells without predried treatment has enhanced the hydrogen content in the gas fraction.

XRD (X-Ray Diffraction) Analysis of the Stabilized Ash

2013 ◽  
Vol 459 ◽  
pp. 7-10
Author(s):  
Hai Ying Zhang ◽  
Shu Zhen Li
Keyword(s):  
Heavy Metals ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Waste Incineration ◽  
Municipal Solid Waste Incineration ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Leaching Toxicity ◽  
Mineralogical Compositions

MSWI (municipal solid waste incineration) fly ash, generated in incineration process of municipal solid waste, contains lots of heavy metals, which will do harm do the environment if extracted. In this work, the ash is stabilized by cement to reduce leaching toxicity of heavy metals. Besides, mineralogical compositions of the product of different cement / ash ratios after conservation for different period were analyzed by means of XRD (X-ray diffraction). It was found that major mineralogical compositions CaCO3, Ca (0H)2 and C-H-S hydration products. Content of Ca (0H)2 and C-H-S rises with increase of conservation period and cement / ash ratio.

Preparation of epitaxial La1−xSrxMnO3 films on SrTiO3(001) by dipping-pyrolysis process

1997 ◽  
Vol 12 (2) ◽  
pp. 541-545 ◽  
Author(s):  
T. Manabe ◽  
I. Yamaguchi ◽  
W. Kondo ◽  
S. Mizuta ◽  
T. Kumagai
Keyword(s):  
Heat Treatment ◽  
Single Crystals ◽  
Space Mapping ◽  
Reciprocal Space ◽  
Pyrolysis Process ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
X Ray ◽  
Metallic Conduction ◽  
Conduction Behavior

La1−xSrxMnO3 (LSMO) (x = 0−0.3) films were prepared on SrTiO3(001) substrates by the dipping-pyrolysis process using metal naphthenates as starting materials. Epitaxially grown LSMO films were obtained by heat treatment at 800–1200 °C; the fluctuation of alignment of these films, evaluated by reciprocal-space mapping of asymmetric x-ray diffraction, was markedly small, as comparable to that of the substrates. The LSMO films with x = 0.1−0.3 showed metallic conduction behavior at 25–300 K, and the resistivity was as low as that of LSMO single crystals, e.g., 4.5 × 10−4 Ω · cm at 150 K for the film with x = 0.3.

Potential Evaluation of Gray Clay as Adsorbent of Heavy Metals Zinc (II) and Lead (II)

2014 ◽  
Vol 798-799 ◽  
pp. 622-627
Author(s):  
Wellington Siqueira Lima ◽  
José Vanderley Nascimento Silva ◽  
Aline Cadigna Lima Patrício ◽  
Guilherme Costa Oliveira ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Heavy Metals ◽  
Factorial Design ◽  
Metal Removal ◽  
Physical Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Capacity ◽  
Adsorption Of Nitrogen ◽  
Potential Evaluation ◽  
Good Percentage

The problems caused by contamination of heavy metals generate a growing need to implement technologies to reduce or eliminate them. This work aims to evaluate the potential of gray clay, the process of removal of zinc and lead from synthetic effluents in finite bath system. The clay was characterized by: X-ray diffraction, X-ray Spectroscopy Energy Dispersive and Physical Adsorption of Nitrogen. The tests were performed finite bath following a 22 factorial design, with the variables: pH and initial concentrations of metal. The clays were evaluated for their removal capacity and rate of metal removal. After the characterization and evaluation, it was found that the gray clay comprises clay of the groups of kaolinite and mica. The results of the factorial design shown that the adsorption of the metals zinc and lead can be developed with good percentage of removal.

Immobilization of ASH by Microwave Melting

1992 ◽  
Vol 269 ◽  
Author(s):  
Kazuki Morita ◽  
Vinh Q. Nguyen ◽  
Ron Nakaoka ◽  
John D. Mackenzie
Keyword(s):  
Electron Microscopy ◽  
Lithium Carbonate ◽  
Microwave Oven ◽  
Toxicity Characteristic Leaching Procedure ◽  
Leaching Rate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Leaching Procedure ◽  
Pb Immobilization ◽  
Scanning Electron

ABSTRACTNon-radioactive ash was immobilized via microwave melting. The ash composed mainly of silica (SiO2), titania (TiO2), calcia (CaO), alumina (Al2O3), and carbon (C). The ash was melted with various additives, such as magnetite (Fe3O4), lithium carbonate (Li2CO3), sodium carbonate (Na2CO3), and boron oxide (B2O3) by using a 2.45 GHz, 750 W microwave oven. Samples with different ash and additive concentrations were melted when subjected to microwave radiation. Ease of melting was dependent on the carbon and magnetite concentrations. Melted samples were characterized by X-ray diffraction and scanning electron microscopy (SEM), and subjected to the Toxicity Characteristic Leaching Procedure in regard to lead (Pb) immobilization. Melted samples with more than 30 wt% additives has an undetectable leaching rate of less than 0.1 ppm of lead for TCLP test, which was found to be due to the reduction and evaporation of the lead during melting. More than 80 % of the lead was lost through evaporation leaving less than 0.1 wt% Pb in the melted glass.

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