scholarly journals Application of raw volcanic rock found in Etna valley as an adsorbent of chromates, arsenates and selenates

10.30544/366 ◽  
2018 ◽  
Vol 24 (2) ◽  
pp. 133-144
Author(s):  
Mladen Dobrivoje Bugarčić ◽  
Milan Milivojević ◽  
Aleksandar Marinković ◽  
Branislav Marković ◽  
Miroslav Sokić ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Volcanic Rock ◽  
Adsorption Capacity ◽  
Gravimetric Analysis ◽  
Adsorption Efficiency ◽  
Chemical Methods ◽  
Physical Methods ◽  
Physicochemical Methods ◽  
Equilibrium Adsorption Capacity

This paper aims to determine the potential of volcanic rock found in Etna valley as an adsorbent of heavy metals in anionic form (chromates, arsenates, and selenates). Characterization of the volcanic rock was done with chemical methods (AAS, AES, gravimetric analysis, XRF), physicochemical methods (XRD, FTIR, SEM, DTA, DTG) and physical methods (porosity measurement, Microscopy in transmitted light). Also, equilibrium adsorption capacity was determined. All the results of adsorption capacity were satisfying considering the mineral composition, granulation, and porosity. The removal efficiency of chromates was the biggest (above 30 %) with adsorption capacity of 15.6 mg Cr g-1. The lowest adsorption efficiency was with the selenates, approximately 18 %.

scholarly journals Metals recovery from acid mine drainage

2021 ◽  
Vol 10 (1) ◽  
pp. 23-32
Author(s):  
Alena Luptáková ◽  
Magdaléna Bálintová ◽  
Jana Jenčárová ◽  
Eva Mačingová ◽  
Mária Praščáková
Keyword(s):  
Heavy Metals ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Chemical Methods ◽  
Acid Mine ◽  
Metals Recovery ◽  
Metals Removal ◽  
Iron Sulphides ◽  
Physicochemical Methods ◽  
Reducing Bacteria

The objectives of the present work give the results view of some physicochemical, chemical and biological-chemical methods for the heavy metals removal from Acid Mine Drainage (AMD). The background of the studied physicochemical methods was the adsorption by turf, chemical methods the heavy metals precipitation by the neutralization with NaOH. The principles of the biological-chemical methods were the bioprecipitation by the applications of sulphate-reducing bacteria (SRB), the sorption by the bacterially produced iron sulphides and sorption by brown coal bio-modified by micromycetes.

scholarly journals Characteristics of Heavy Metals Adsorption Cu, Pb and Cd Using Synthetics Zeolite Zsm-5

2016 ◽  
Vol 20 (2) ◽  
pp. 77 ◽  
Author(s):  
. Priyadi ◽  
. Iskandar ◽  
. Suwardi ◽  
Rino Rakhmata Mukti
Keyword(s):  
Heavy Metals ◽  
Adsorption Capacity ◽  
Negative Charge ◽  
Total Pore Volume ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Heavy Metal Adsorption ◽  
Batch System ◽  
Adsorption Data

It is generally known that zeolite has potential for heavy metal adsorption. The  objectives of this study were to synthesize and characterize zeolite ZSM-5 and to figure out the adsorption capacity of zeolite ZSM-5 for heavy metals of Cu2+, Pb2+ and Cd2+. Characterization of zeolite ZSM-5 included some variables i.e. crystal structure (XRD), morphology (SEM), specific surface area and total pore volume (N2 physisorption). Adsorption capacity of zeolite ZSM-5 was analysed using a batch system with heavy metals of Cu2+, Pb2+ and Cd2+ in various concentrations (50, 100, 150, 200 and 250 ppm) with contact times 30, 60, 90, 120 and 250 minutes. Adsorption data was calculated by Langmuir and Freundlich isotherm. The results showed that the maximum adsorption capacity of zeolite ZSM-5 against heavy metals of Pb2+, Cu2+, and Cd2+, were 74.07, 69.93 and 60.24 mg g-1, respectively. These indicated that synthetic zeolite ZSM-5 had potential to adsorb heavy metals. The results also suggested that the adsorption capacity was affected by the pore size of zeolite, negative charge of zeolite, diameter of hydrated and electronegative ion.

Coordination Compounds of Some 3d-Transition Metal Ions with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)- thiosemicarbazide

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Madalina Angelusiu ◽  
Maria Negoiu ◽  
Stefania-Felicia Barbuceanu ◽  
Tudor Rosu
Keyword(s):  
Coordination Compounds ◽  
Magnetic Moments ◽  
Thermo Gravimetric Analysis ◽  
Electronic Spectroscopy ◽  
Transition Metal Ions ◽  
Synthesis And Characterization ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
New Compounds

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.

Mercury Removal from Wastewater by Steamed Hoof Powder

1999 ◽  
Vol 40 (7) ◽  
pp. 109-116 ◽  
Author(s):  
M. H. Ansari ◽  
A. M. Deshkar ◽  
P. S. Kelkar ◽  
D. M. Dharmadhikari ◽  
M. Z. Hasan ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Light Metal ◽  
Mercury Removal ◽  
High Adsorption ◽  
Surface Sites ◽  
Ph Values ◽  
High Adsorption Capacity

Steamed Hoof Powder (SHP), size < 53μ, was observed to have high adsorption capacity for Hg(II) with >95% removal from a solution containing 100 mg/L of Hg(II) with only 0.1% (W/V) concentration of SHP. The SHP has good settling properties and gives clear and odour free effluent. Studies indicate that pH values between 2 and 10 have no effect on the adsorption of Hg(II) on SHP. Light metal ions like Na+, K+, Ca2+ and Mg2+ up to concentrations of 500 mg/L and heavy metals like Cu2+, Zn2+, Cd2+, Co2+, Pb2+, Ni2+, Mn2+, Cr3+, Cr6+, Fe2+ and Fe3+ up to concentrations of 100 mg/L do not interfere with the adsorption process. Anions like sulphate, acetate and phosphate up to concentrations of 200 mg/L do not interfere. Chloride interferes in the adsorption process when Hg(II) concentration is above 9.7 mg/L. The adsorption equilibrium was established within two hours. Studies indicate that adsorption occurs on the surface sites of the adsorbent.

Mn-Mo-O Catalysts for Methanol Oxidation. I. Preparation and Characterization of the Catalysts

1992 ◽  
Vol 57 (12) ◽  
pp. 2529-2538 ◽  
Author(s):  
Krasimir Ivanov ◽  
Penka Litcheva ◽  
Dimitar Klissurski
Keyword(s):  
Methanol Oxidation ◽  
Solution Concentration ◽  
Alkaline Media ◽  
Acidic Media ◽  
Chemical Methods ◽  
X Ray ◽  
Ph Values ◽  
Precipitate Composition

Mn-Mo-O catalysts with a different Mo/Mn ratio have been prepared by precipitation. The precipitate composition as a function of solution concentration and pH was studied by X-ray, IR, thermal and chemical methods. Formation of manganese molybdates with MnMoO4.1.5H2O, Mn3Mo3O12.2.5H2O, and Mn3Mo4O15.4H2O composition has been supposed. It is concluded that pure MnMoO4 may be obtained in both acid and alkaline media, the pH values depending on the concentration of the initial solutions. The maximum Mo/Mn ratio in the precipitates is 1.33. The formation of pure Mn3Mo4O15.4H2O is possible in weakly acidic media. This process is favoured by increasing the concentration of initial solutions.

Development and Characterization of Amine-Clay Hybrid Adsorbents for CO2 Capture

2016 ◽  
Vol 1133 ◽  
pp. 547-551 ◽  
Author(s):  
Ali E.I. Elkhalifah ◽  
Mohammad Azmi Bustam ◽  
Azmi Mohd Shariff ◽  
Sami Ullah ◽  
Nadia Riaz ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Surface Properties ◽  
Molar Mass ◽  
Adsorption Ability ◽  
Stepwise Increase ◽  
Inverse Effect ◽  
Bet Method ◽  
Sodium Form

The present work aims at a better understanding of the influences of the intercalated mono-, di- and triethanolamines on the characteristics and CO2 adsorption ability of sodium form of bentonite (Na-bentonite). The results revealed that the molar mass of intercalated amines significantly influenced the structural and surface properties as well as the CO2 adsorption capacity of Na-bentonite. In this respect, a stepwise increase in the d-spacing of Na-bentonite with the molar mass of amine was recorded by XRD technique. However, an inverse effect of the molar mass of amine on the surface area was confirmed by BET method. CO2 adsorption experiments on amine-bentonite hybrid adsorbents showed that the CO2 adsorption capacity inversly related to the molar mass of amine at 25 ͦC and 101 kPa. Accordingly, Na-bentonite modified by monoethanolammonium cations adsorbed as high as 0.475 mmol CO2/g compared to 0.148 and 0.087 mmol CO2/g for that one treated with di- and triethanolammonium cations, respectively.

scholarly journals Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1757
Author(s):  
Yesica Vicente-Martínez ◽  
Manuel Caravaca ◽  
Antonio Soto-Meca ◽  
Miguel Ángel Martín-Pereira ◽  
María del Carmen García-Onsurbe
Keyword(s):  
Magnetic Nanoparticles ◽  
Nitrate Content ◽  
Adsorption Efficiency ◽  
Experimental Conditions ◽  
Dependent Behavior ◽  
Before And After ◽  
Naoh Solution ◽  
High Concentrations ◽  
Interference Studies

This paper presents a novel procedure for the treatment of contaminated water with high concentrations of nitrates, which are considered as one of the main causes of the eutrophication phenomena. For this purpose, magnetic nanoparticles functionalized with silver (Fe3O4@AgNPs) were synthesized and used as an adsorbent of nitrates. Experimental conditions, including the pH, adsorbent and adsorbate dose, temperature and contact time, were analyzed to obtain the highest adsorption efficiency for different concentration of nitrates in water. A maximum removal efficiency of 100% was reached for 2, 5, 10 and 50 mg/L of nitrate at pH = 5, room temperature, and 50, 100, 250 and 500 µL of Fe3O4@AgNPs, respectively. The characterization of the adsorbent, before and after adsorption, was performed by energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller analysis and Fourier-transform infrared spectroscopy. Nitrates can be desorbed, and the adsorbent can be reused using 500 µL of NaOH solution 0.01 M, remaining unchanged for the first three cycles, and exhibiting 90% adsorption efficiency after three regenerations. A deep study on equilibrium isotherms reveals a pH-dependent behavior, characterized by Langmuir and Freundlich models at pH = 5 and pH = 1, respectively. Thermodynamic studies were consistent with physicochemical adsorption for all experiments but showed a change from endothermic to exothermic behavior as the temperature increases. Interference studies of other ions commonly present in water were carried out, enabling this procedure as very selective for nitrate ions. In addition, the method was applied to real samples of seawater, showing its ability to eliminate the total nitrate content in eutrophized waters.

scholarly journals Stormwater Runoff Treatment Using Pervious Concrete Modified with Various Nanomaterials: A Comprehensive Review

2021 ◽  
Vol 13 (15) ◽  
pp. 8552
Author(s):  
Vahid Alimohammadi ◽  
Mehdi Maghfouri ◽  
Delaram Nourmohammadi ◽  
Pejman Azarsa ◽  
Rishi Gupta ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Compressive Strength ◽  
Adsorption Capacity ◽  
Removal Rate ◽  
Stormwater Runoff ◽  
Infiltration Rate ◽  
Stormwater Treatment ◽  
Adsorption Mechanisms ◽  
Wide Range ◽  
Adsorption Processes

Clean water is a vital need for all living creatures during their lifespan. However, contaminated stormwater is a major issue around the globe. A wide range of contaminants, including heavy metals, organic and inorganic impurities, has been discovered in stormwater. Some commonly utilized methods, such as biological, physical and chemical procedures, have been considered to overcome these issues. However, these current approaches result in moderate to low contaminant removal efficiencies for certain classes of contaminants. Of late, filtration and adsorption processes have become more featured in permeable concretes (PCs) for the treatment of stormwater. As nanoparticles have vast potential and unique characterizations, such as a higher surface area to cure polluted stormwater, employing them to improve permeable concretes’ capabilities in stormwater treatment systems is an effective way to increase filtration and adsorption mechanisms. The present study reviews the removal rate of different stormwater contaminants such as heavy metals, organic and other pollutants using nanoparticle-improved PC. The application of different kinds of nanomaterials in PC as porous media to investigate their influences on the properties of PC, including the permeability rate, compressive strength, adsorption capacity and mix design of such concrete, was also studied. The findings of this review show that different types of nanomaterials improve the removal efficiency, compressive strength and adsorption capacity and decrease the infiltration rate of PC during the stormwater treatment process. With regard to the lack of comprehensive investigation concerning the use of nanomaterials in PC to treat polluted stormwater runoff, this study reviews 242 published articles on the removal rate of different stormwater contaminants by using PC improved with nanoparticles.

scholarly journals Fabrication and characterization of hexadecyl acrylate cross-linked phase change microspheres

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 69-75
Author(s):  
Haoran Yun ◽  
Xingxiang Zhang
Keyword(s):  
Phase Change ◽  
Smooth Surface ◽  
Bone Conduction ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Orthopedic Implant ◽  
Thermal Gravimetric ◽  
Fabrication And Characterization ◽  
Fast Release

AbstractMicrospheres with phase change properties were fabricated by polymerization of hexadecyl acrylate (HA) and different cross-linking agents. The samples were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA). The results show that, the samples that added cross-linking agents have a smooth surface and the latent heat of them is different. The experiments show that all of the cross-linked copolymer shells can be made into temperature controlled release microspheres. These materials can be potentially applied in the field of thermal energy storage. β-tricalcium phosphate was encapsulated in microspheres to obtain one with a fast release effect. It will effectively promote bone conduction when these microspheres were implanted into a bone defect. This microsphere can be used for orthopedic implant or coating of instrument in the future.

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