Effect of Temperature on the Physical, Electro-Chemical and Adsorption Properties of Carbon Micro-Spheres Using Hydrothermal Carbonization Process

This research deals with the effect of the temperature on the physical, thermal, electrochemical, and adsorption properties of the carbon micro-spheres using hydrothermal carbonization (HTC). Until recently, limited research has been conducted regarding the effects of delignification during the HTC process of biomass residues especially Dimocarpus longan. In this regard, lignin was first extracted from the lingo-cellulosic waste of Longan fruit peel (Dimocarpus longan). The holocellulose (HC) separated from lignin and raw biomass substrates (Longan fruit exocarp/peel powder, LFP) were carbonized at different temperatures using water as the green catalyst. Hydrothermal carbonization (HTC) was performed for both of the samples (LFP and HC) at 200 °C, 250 °C, and 300 °C for 24 h each. The surface morphological structures, the porosity, and the Brunauer-Emmett-Teller (BET) surface area of the prepared micro-spherical carbon were determined. The BET surface areas obtained for HC-based carbon samples were lower than that of the raw LFP based carbon samples. The carbon obtained was characterized using ultimate and proximate analyses. The surface morphological features and phase transformation of the synthesized micro-spherical carbon was characterized by a field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analysis. The results demonstrated that the extraction of lignin could significantly alter the end properties of the synthesized carbon sample. The carbon spheres derived from LFP showed a higher carbon content than the HC-based carbon. The absence of lignin in the holo-cellulose (HC) made it easy to disintegrate in comparison to the raw, LFP-based carbon samples during the HTC process. The carbonaceous samples (LFP-300 and HC-300) prepared at 300 °C were selected and their adsorption performance for Pb (II) cations was observed using Langmuir, Freundlich, and Temkin linear isotherm models. At 30 °C, the equilibrium data followed the Langmuir isotherm model more than the Freundlich and Temkin model for both the LFP-300 sample and the HC-300 sample. The potential of the synthesized carbon microspheres were further analyzed by thermodynamic characterizations of the adsorption equilibrium system.

Download Full-text

Green Biosynthesis of Silver Nanoparticles Using Leaf Extract of Carissa carandas L. and Their Antioxidant and Antimicrobial Activity against Human Pathogenic Bacteria

Biomolecules ◽

10.3390/biom11020299 ◽

2021 ◽

Vol 11 (2) ◽

pp. 299

Author(s):

Reetika Singh ◽

Christophe Hano ◽

Gopal Nath ◽

Bechan Sharma

Keyword(s):

Silver Nanoparticles ◽

Pathogenic Bacteria ◽

Leaf Extract ◽

Room Temperature ◽

Xrd Analysis ◽

Antibacterial Activities ◽

Effect Of Temperature ◽

Human Pathogenic Bacteria ◽

Carissa Carandas ◽

Antioxidant And Antimicrobial Activity

Carissa carandas L. is traditionally used as antibacterial medicine and accumulates many antioxidant phytochemicals. Here, we expand this traditional usage with the green biosynthesis of silver nanoparticles (AgNPs) achieved using a Carissa carandas L. leaf extract as a reducing and capping agent. The green synthesis of AgNPs reaction was carried out using 1mM silver nitrate and leaf extract. The effect of temperature on the synthesis of AgNPs was examined using room temperature (25 °C) and 60 °C. The silver nanoparticles were formed in one hour by stirring at room temperature. In this case, a yellowish brown colour was developed. The successful formation of silver nanoparticles was confirmed by UV–Vis, Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analysis. The characteristic peaks of the UV-vis spectrum and XRD confirmed the synthesis of AgNPs. The biosynthesised AgNPs showed potential antioxidant activity through DPPH assay. These AgNPs also exhibited potential antibacterial activity against human pathogenic bacteria. The results were compared with the antioxidant and antibacterial activities of the plant extract, and clearly suggest that the green biosynthesized AgNPs can constitute an effective antioxidant and antibacterial agent.

Download Full-text

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

Materials ◽

10.3390/ma14010063 ◽

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.

Download Full-text

CHARACTERISTICS AND ADSORPTION PERFORMANCE OF FORMULATED TRIKOTAC FILTER AIDS

Jurnal Teknologi ◽

10.11113/jt.v81.12662 ◽

2019 ◽

Vol 81 (3) ◽

Author(s):

N. Masdiana ◽

M. Rashid ◽

S. Hajar ◽

M. R. Ammar

Keyword(s):

Particle Size ◽

Activated Carbon ◽

Particle Density ◽

Adsorption Properties ◽

The Other ◽

Bet Surface Area ◽

Adsorption Performance ◽

Filtration System ◽

Filter Aids ◽

The Relationship

TrikotAC filter aids is a combination of a pre-coating material PreKot™ with two adsorbents; activated carbon and lime and their characteristics were investigated in this study. TrikotAC was formulated into three different weight ratios of 5:1:94, 10:1:89 and 10:5:85, respectively. The relationship between adsorption properties and characteristics of the formulated materials particle size distribution, particle density, bulk density, and BET surface area were investigated. The results showed that the adsorption capacity for TrikotAC 10:5:85 (11.88 mg/g) was higher than for the other formulated filter aids samples, and the formulated filter aids material TrikotAC showed promising characteristic as a filter aids and adsorbent for organic compound in fabric filtration system.

Download Full-text

Oxidized BPL Carbons

Adsorption Science & Technology ◽

10.1177/0263617499010001-407 ◽

1993 ◽

Vol 10 (1-4) ◽

pp. 75-84 ◽

Cited By ~ 15

Author(s):

S.S. Barton ◽

M.J.B. Evans ◽

J.A.F. Macdonald

Keyword(s):

Nitric Acid ◽

Surface Area ◽

Water Adsorption ◽

Adsorption Properties ◽

Bet Surface Area ◽

Adsorption Sites ◽

A Value ◽

Nitrogen Desorption ◽

Oxidized Carbon ◽

Increasing Temperature

A series of oxidized carbons has been prepared by treatment of the carbon with concentrated nitric acid at various temperatures, and the surface and adsorption properties of the prepared carbons studied. Water adsorption was modelled using a recently derived equation capable of predicting a value for the primary adsorption sites on the surface of a microporous carbon while fitting the experimentally determined isotherm at high relative pressures. The concentration of primary sites was seen to increase with increasing temperature of oxidation. The very highly oxidized carbon samples were found to have a significantly lower BET surface area determined from nitrogen desorption at 77 K and higher apparent density measured from mercury displacement.

Download Full-text

Effective Removal of Malachite Green from Aqueous Solutions Using Magnetic Nanocomposite: Synthesis, Characterization, and Equilibrium Study

Adsorption Science & Technology ◽

10.1155/2021/2359110 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Ali Q. Alorabi

Keyword(s):

Surface Area ◽

Malachite Green ◽

Chemical Activation ◽

Aqueous Media ◽

Kinetic Studies ◽

Cost Effective ◽

Magnetic Nanocomposite ◽

Bet Surface Area ◽

Isotherm Models ◽

Order Kinetic

In this work, magnetized activated Juniperus procera leaves (Fe3O4@AJPL) were successfully prepared via chemical activation of JPL and in situ coprecipitation with Fe3O4. A Fe3O4@AJPL nanocomposite was successfully applied for the elimination of malachite green (MG) dye from aqueous media. The prepared Fe3O4@AJPL adsorbent was characterized by SEM, EDX, TEM, XRD, FTIR, TGA, and BET surface area analyses. The BET surface area and pore size of the Fe3O4@AJPL nanocomposite were found to be 38.44 m2/g and 10.6 nm, respectively. The XRD and FTIR results indicated the formation of a Fe3O4@AJPL nanocomposite. Different parameters, such as pH of the solution (3–8), adsorbent dosage (10–100 mg), temperature (25–45°C), contact time (5-240 min), and initial MG concentrations (20–350 mg/L), for the elimination of the MG dye using Fe3O4@AJPL were optimized and found to be 7, 50 mg, 45°C, 120 min, and 150 mg/L, respectively. The nonlinear isotherm and kinetic studies exhibited a better fitting to second-order kinetic and Langmuir isotherm models, with a maximum monolayer adsorption capacity of 318.3 mg/g at 45°C, which was highly superior to the previously reported magnetic nanocomposite adsorbents. EDX analyses confirmed the presence of nitrogen on the Fe3O4@AJPL surface after MG adsorption. The calculated thermodynamic factors indicated endothermic and spontaneous processes. The desorption of MG dye from Fe3O4@AJPL was performed using a solution of 90% ethanol. Finally, it could be concluded that the designed Fe3O4@AJPL magnetic nanocomposite will be a cost-effective and promising adsorbent for the elimination of MG from aqueous media.

Download Full-text

A study of adsorption isotherms for the removal of herbicide Atlantis WG from aqueous solutions by using Bentonite clay

Baghdad Science Journal ◽

10.21123/bsj.12.1.148-156 ◽

2015 ◽

Vol 12 (1) ◽

pp. 148-156

Author(s):

Baghdad Science Journal

Keyword(s):

Aqueous Solutions ◽

Adsorption Process ◽

Equilibrium Concentration ◽

Bentonite Clay ◽

Langmuir Model ◽

Effect Of Temperature ◽

Isotherm Models ◽

Sorption Data ◽

Freundlich Model ◽

The Subject

The subject of this research involves studying adsorption to removal herbicide Atlantis WG from aqueous solutions by bentonite clay. The equilibrium concentration have been determined spectra photometry by using UV-Vis spectrophotometer. The experimental equilibrium sorption data were analyzed by two widely, Langmuir and Freundlish isotherm models. The Langmuir model gave a better fit than Freundlich model The adsorption amount of (Atlantis WG) increased when the temperature and pH decreased. The thermodynamic parameters like ?G, ?H, and ?S have been calculated from the effect of temperature on adsorption process, is exothermic. The kinetic of adsorption process was studied depending on Lagergren ,Morris ? Weber and Rauschenberg equations.

Download Full-text

3D Porous Graphene/Polyvinyl Alcohol Composites: The Effect of Modification on the Adsorption Properties

NANO ◽

10.1142/s1793292016501253 ◽

2016 ◽

Vol 11 (11) ◽

pp. 1650125 ◽

Cited By ~ 3

Author(s):

Shuang Sun ◽

Xiaofei Ma

Keyword(s):

Polyvinyl Alcohol ◽

Graphene Nanosheets ◽

Adsorption Properties ◽

Isotherm Models ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Porous Structures ◽

Edta Solution ◽

Pseudo Second Order

Polyvinyl alcohol (PVA) was grafted on graphene nanosheets (GN) in the reduction of graphene oxide with hydrazine hydrate. The obtained GN-PVA (GP) suspension was treated with the freezing–thawing cycle to fabricate 3D porous monolithic GP materials, which were modified with carbon disulfide to introduce xanthan groups on the wall of porous materials, marked as GPCs. The characterization of GPCs confirmed that PVA was attached on the surface of GNs, and xanthan groups were effectively functionalized on the porous structures, which were composed of randomly oriented GNs. The Pb[Formula: see text] adsorption pattern for GPC materials was investigated. The kinetic adsorption and isotherm data fit the pseudo second-order kinetic and the Langmuir isotherm models, respectively. The maximum adsorption capacity of Pb[Formula: see text] reached 242.7[Formula: see text]mg/g. And GPCs for Pb[Formula: see text] adsorption could be regenerated with ethylenediamine tetracetic acid (EDTA) solution for repetitious adsorption.

Download Full-text

Effect of Temperature on the Hydrothermal Carbonization of Organic Fertilizers with the Production of Carbon Fuel

Solid Fuel Chemistry ◽

10.3103/s0361521919020071 ◽

2019 ◽

Vol 53 (2) ◽

pp. 105-107

Author(s):

K. O. Krysanova ◽

V. M. Zaichenko ◽

G. A. Sychev ◽

R. L. Is’emin ◽

A. Yu. Krylova

Keyword(s):

Hydrothermal Carbonization ◽

Organic Fertilizers ◽

Effect Of Temperature

Download Full-text

Investigation of Properties Alternation during Super-Critical CO2 Injection in Shale

Applied Sciences ◽

10.3390/app9081686 ◽

2019 ◽

Vol 9 (8) ◽

pp. 1686 ◽

Cited By ~ 3

Author(s):

Sai Wang ◽

Kouqi Liu ◽

Juan Han ◽

Kegang Ling ◽

Hongsheng Wang ◽

...

Keyword(s):

Oil Recovery ◽

Supercritical Co2 ◽

Indentation Test ◽

Nitrogen Adsorption ◽

Xrd Analysis ◽

Bet Surface Area ◽

Co2 Injection ◽

Co2 Flooding ◽

Recovery Method ◽

Injection Process

The low recovery of oil from tight liquid-rich formations is still a major challenge for a tight reservoir. Thus, supercritical CO2 flooding was proposed as an immense potential recovery method for production improvement. While up to date, there have been few studies to account for the formation properties’ variation during the CO2 Enhanced Oil Recovery (EOR) process, especially investigation at the micro-scale. This work conducted a series of measurements to evaluate the rock mechanical change, mineral alteration and the pore structure properties’ variation through the supercritical CO2 (Sc-CO2) injection process. Corresponding to the time variation (0 days, 10 days, 20 days, 30 days and 40 days), the rock mechanical properties were analyzed properly through the nano-indentation test, and the mineralogical alterations were quantified through X-ray diffraction (XRD). In addition, pore structures of the samples were measured through the low-temperature N2 adsorption tests. The results showed that, after Sc-CO2 injection, Young’s modulus of the samples decreases. The nitrogen adsorption results demonstrated that, after the CO2 injection, the mesopore volume of the sample would change as well as the specific Brunauer–Emmett–Teller (BET) surface area which could be aroused from the chemical reactions between the CO2 and some authigenic minerals. XRD analysis results also indicated that mesopore were altered due to the chemical reaction between the injected Sc-CO2 and the minerals.

Download Full-text

Interconnected Micro, Meso, and Macro Porous Activated Carbon from Bacterial Nanocellulose for Superior Adsorption Properties and Effective Catalytic Performance

Molecules ◽

10.3390/molecules25184063 ◽

2020 ◽

Vol 25 (18) ◽

pp. 4063

Author(s):

Arnon Khamkeaw ◽

Tatdanai Asavamongkolkul ◽

Tianpichet Perngyai ◽

Bunjerd Jongsomjit ◽

Muenduen Phisalaphong

Keyword(s):

Activated Carbon ◽

Reaction Temperature ◽

Mass Transfer Rate ◽

Catalyst Support ◽

Catalytic Performance ◽

Adsorption Properties ◽

Bet Surface Area ◽

Ethanol Conversion ◽

Bacterial Nanocellulose ◽

Effective Performance

The porous carbon (bacterial cellulose (BC)-activated carbon (AC)(BA)) prepared via two-step activation of bacterial nanocellulose by treatments with potassium hydroxide (KOH) and then phosphoric acid (H3PO4) solutions showed superior adsorption properties and effective performance as catalyst support. BC-AC(BA) had an open and interconnected multi-porous structure, consisting of micropores (0.23 cm3/g), mesopores (0.26 cm3/g), and macropores (4.40 cm3/g). The BET surface area and porosity were 833 m2/g and 91.2%, respectively. The methylene blue adsorption test demonstrated that BC-AC(BA) was superior in its mass transfer rate and adsorption capacities. Moreover, BC-AC(BA) modified by H3PO4 treatment showed a significant enhancement of catalytic performance for dehydration of ethanol. At the reaction temperature of 250–400 °C, 30P/BC-AC(BA) gave ethanol conversion at 88.4–100%, with ethylene selectivity of 82.6–100%, whereas, high selectivity for diethyl ether (DEE) at 75.2%, at ethanol conversion of 60.1%, was obtained at the reaction temperature of 200 °C.

Download Full-text