scholarly journals Carbonaceous Adsorbent Derived from Sulfur-Impregnated Heavy Oil Ash and Its Lead Removal Ability from Aqueous Solution

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1484
Author(s):  
Takaaki Wajima
Keyword(s):  
Heavy Oil ◽  
Potassium Hydroxide ◽  
Maximum Adsorption Capacity ◽  
Lead Removal ◽  
Lead Adsorption ◽  
Freundlich Model ◽  
N2 Atmosphere ◽  
Potassium Sulfide ◽  
Better Than ◽  
Carbonaceous Adsorbent

A novel carbonaceous adsorbent was prepared from sulfur-impregnated heavy oil ash via pyrolysis using potassium sulfide (K2S) solution, and its ability to remove lead (Pb2+) from aqueous solutions was examined. It was compared with an adsorbent synthesized by conventional pyrolysis using potassium hydroxide (KOH) solution. Specifically, the raw ash was immersed in 1 M K2S solution or 1 M KOH solution for 1 day and subsequently heated at 100–1000 °C in a nitrogen (N2) atmosphere. After heating for 1 h, the solid was naturally cooled in N2 atmosphere, and subsequently washed and dried to yield the product. Regardless of the pyrolysis temperature, the product generated using K2S (Product-K2S) has a higher sulfur content than that obtained using KOH (Product-KOH). Moreover, Product-K2S has a higher lead removal ability than Product-KOH, whereas the specific surface area of the former is smaller than that of the latter. Product-K2S obtained at 300 °C (Product-K2S-300) achieves the highest lead adsorption and a high selective lead removal from a ternary Pb2+–Cu2+–Zn2+ solution. The equilibrium capacity of Product-K2S-300 was found to fit the Langmuir model better than the Freundlich model, and its calculated maximum adsorption capacity is 0.54 mmol/g. From the ternary Pb2+–Cu2+–Zn2+ solution, the order of adsorption by Product-K2S-300 is Pb2+ > Cu2+ > Zn2+, and the removal of Pb2+ and Cu2+ increases as the pH of the solution increases.

scholarly journals Adsorption Equilibrium of a Herbicide (Pendimethalin) onto Natural Clay

2005 ◽  
Vol 23 (6) ◽  
pp. 437-453 ◽  
Author(s):  
M.S. El-Geundi ◽  
T.E. Farrag ◽  
H.M. Abd El-Ghany
Keyword(s):  
Particle Size ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Maximum Adsorption Capacity ◽  
Natural Clay ◽  
Freundlich Model ◽  
Adsorption Data ◽  
Effect Of Particle Size ◽  
System Variables ◽  
Better Than

The equilibrium adsorption of a herbicide (pendimethalin) onto natural clay from aqueous solutions was studied experimentally using different system variables. The influence of such variables, such as particle size (dp), pH and temperature, on the adsorption capacity was studied. Equilibrium modelling was carried out using the Langmuir, Freundlich and Redlich—Peterson models with the corresponding constants being calculated for the different system variables. The results indicate that the maximum adsorption capacity (qmax) at an acidic pH value (3.44) was approximately double that observed at an alkaline pH value (9.62). It was also found that the effect of particle size was significant and that the temperature plays an interesting role in the adsorption process. The enthalpy change (ΔH) for adsorption was evaluated as −29.36 kJ/mol. It is clear from the results of this study that the Freundlich model fitted the experimental adsorption data significantly better than the Langmuir or the Redlich—Peterson models.

Adsorption kinetics and thermodynamics of acid Bordeaux B from aqueous solution by graphene oxide/PAMAMs

2015 ◽  
Vol 72 (7) ◽  
pp. 1217-1225 ◽  
Author(s):  
Fan Zhang ◽  
Shengfu He ◽  
Chen Zhang ◽  
Zhiyuan Peng
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Maximum Adsorption Capacity ◽  
Freundlich Model ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Effects Of Media ◽  
Better Than

Graphene oxide/polyamidoamines dendrimers (GO/PAMAMs) composites were synthesized via modifying GO with 2.0 G PAMAM. The adsorption behavior of the GO/PAMAMs for acid Bordeaux B (ABB) was studied and the effects of media pH, adsorption time and initial ABB concentration on adsorption capacity of the adsorbent were investigated. The optimum pH value of the adsorption of ABB onto GO/PAMAMs was 2.5. The maximum adsorption capacity increased from 325.78 to 520.83 mg/g with the increase in temperature from 298 to 328 K. The equilibrium data followed the Langmuir isotherm model better than the Freundlich model. The kinetic study illustrated that the adsorption of ABB onto GO/PAMAMs fit the pseudo-second-order model. The thermodynamic parameters indicated that the adsorption process was physisorption, and also an endothermic and spontaneous process.

scholarly journals Behavior of Reduction Precipitation of Nickel Adsorbed on the Surface of Sulfur-Impregnated Carbonaceous Cotton

2018 ◽  
Vol 2 (5) ◽  
pp. 1-6
Author(s):  
Keyword(s):  
Metallic Nickel ◽  
Maximum Adsorption Capacity ◽  
Reduction Temperature ◽  
Tubular Furnace ◽  
X Ray Diffraction ◽  
Precipitation Behavior ◽  
Freundlich Model ◽  
Reduction Treatment ◽  
N2 Atmosphere ◽  
Langmuir Isotherm Model

In this study, reduction treatment was applied to nickel adsorbed on a sulfur-impregnated carbonaceous cotton prepared using sulfide aqueous solutions, and the precipitation behavior of nickel was determined. Two types of sulfide solutions, K2S and Na2S, were used for preparation of the sulfur-impregnated adsorbent. A cotton immersed in sulfide solution was pyrolyzed in an electric tubular furnace to obtain the fibrous adsorbent. Nickel was adsorbed on the surface of the adsorbent by passing a 10 mM Ni(NO3)2 solution through the obtained adsorbent, and the fibrous adsorbent adsorbed nickel was heated in N2 atmosphere using an electric tubular furnace as reduction treatment. The adsorbents on each process were analyzed by X-ray diffraction (XRD) and observed by scanning electron microscope (SEM), respectively, and the effects of sulfide type, concentration and reduction temperature on the precipitation behavior of nickel adsorbed on the sulfur-impregnated cotton was examined. The adsorption amount of the adsorbent obtained using 1.0 M Na2S was higher than that using 1.0 M K2S. From the analysis of adsorption isotherms using Langmuir and Freundlich model, the Langmuir model matched the data better than the Freundlich model for both adsorbents, and maximum adsorption capacity calculated from the Langmuir isotherm model for the adsorbent obtained using Na2S was 0.43 mmol/g, which was higher than that using K2S (0.27 mmol/g). Ni3S2 was precipitated on the adsorbent prepared using 1.0 M K2S by reduction treatment at more than 800 oC, while metallic nickel was precipitated on the adsorbent prepared using 0.5 M Na2S by reduction treatment at more than 800 oC. The amount and size of the precipitated particles increased with increasing the reduction temperature.

Machinability and Microstructure of SiC/h-BN Nano-Composites

2008 ◽  
Vol 569 ◽  
pp. 45-48
Author(s):  
Hai Yun Jin ◽  
Guan Jun Qiao ◽  
Zong Ren Peng ◽  
Ji Qiang Gao
Keyword(s):  
Fracture Strength ◽  
Nano Composites ◽  
Weak Interface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sic Particles ◽  
N2 Atmosphere ◽  
The Matrix ◽  
Better Than

SiC particles coated with nano-BN were synthesized and the machinable SiC/BN ceramic nano-composites were fabricated by Plasma Active Sintering (PAS) in N2 atmosphere. The existing and distribution of h-BN phase were revealed by X-ray diffraction (XRD), and SEM. For the existing of weak interface between h-BN and SiC grains, the machinability of both SiC/BN micro-composites and nano-composites were improved obviously. Because the nano-sized h-BN crystals were homogeneously dispersed around the SiC grains of the matrix, the fracture strength of the nano-composites was better than the SiC/h-BN micro-composite.

Equilibrium and kinetic studies on biosorption of Pb(II) by common edible macrofungi: a comparative study

2016 ◽  
Vol 62 (4) ◽  
pp. 329-337 ◽  
Author(s):  
Yuan Jiang ◽  
Ruixia Hao ◽  
Shiqin Yang
Keyword(s):  
Kinetic Studies ◽  
Risk Level ◽  
Individual Species ◽  
Lead Removal ◽  
Freundlich Model ◽  
Hypsizygus Marmoreus ◽  
Agrocybe Cylindracea ◽  
Removal Capacity ◽  
Equilibrium Data ◽  
Pseudo Second Order

In this work, we studied the natural bioaccumulation and biosorption of Pb(II) in several common edible macrofungi. The macrofungi include the following species: Lentinus edodes, Pleurotus eryngii, Flammulina velutipes, Hypsizygus marmoreus, and Agrocybe cylindracea. The present analysis of Pb(II) revealed distinct capabilities of metal accumulation among individual species. Moreover, the natural concentrations of lead did not reach a health risk level when cultivated in uncontaminated soil. In the biosorption experiment by edible macrofungi, we found that the equilibrium data of living sporocarp (P. eryngii and H. marmoreus) and the homogenate of L. edodes and F. velutipes fit the Freundlich model well. Other data samples exhibited a better fit to the Langmuir model. The edible macrofungi showed a higher lead removal capacity than did other biosorbents. Furthermore, the pseudo-second-order kinetics model exhibited the best fit to the biosorption processes. The effectiveness of edible macrofungi as biosorbents for Pb(II) was confirmed.

scholarly journals Lead removal from water – dependence on the form of carbon and surface functionalization

RSC Advances ◽  
2018 ◽  
Vol 8 (33) ◽  
pp. 18355-18362 ◽  
Author(s):  
Chun Sing Kam ◽  
Tik Lun Leung ◽  
Fangzhou Liu ◽  
Aleksandra B. Djurišić ◽  
Mao Hai Xie ◽  
...  
Keyword(s):  
Surface Functionalization ◽  
Functional Group ◽  
Carbon Materials ◽  
Lead Removal ◽  
Nanostructured Carbon ◽  
Lead Adsorption ◽  
Adsorption Performance

Functionalization with same functional group results in varied lead adsorption performance for different nanostructured carbon materials.

scholarly journals Valorization of Uncharred Dry Leaves of Ficus benjamina towards Cr (VI) removal from Water: Efficacy Influencing Factors and mechanism

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Preeti S. Kulkarni ◽  
Varuna S. Watwe ◽  
Abubakar J. Hipparge ◽  
Sana I. Sayyad ◽  
Rutika A. Sonawane ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Maximum Adsorption Capacity ◽  
Equilibration Time ◽  
Aqueous Samples ◽  
Sorption Data ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Better Than ◽  
Work Treatment

AbstractThe potential of uncharred biomaterial derived from dry leaves of Ficusbenjamina (Family: Moraceae,local name: Weeping Fig) plant to remove Cr(VI) from aqueous samples was investigated. In the present work, treatment of dilute acids was used for activating the adsorption centres on the biomass instead of cumbersome charring process. The plant material was characterized using FT-IR, FE-SEM and EDX. Various influencing factors such as pH of equilibrating solution, contact time, Cr (VI) concentrations, adsorbent dose and temperature were optimized to obtain maximum sorption efficacy. The interactions among the biomaterial and Cr (VI) in water were studied by fitting the sorption data in four different adsorption isotherms. The data fitting and experimental evidences indicated formation of monolayer of Cr(VI) over the biomass surface. The process followed pseudo-second order kinetics and was thermodynamically spontaneous under laboratory conditions and reached equilibrium in 24 hours. Maximum adsorption capacity of 56.82 mg/g was obtained at the pH 2 when the concentration before adsorption was 200 mg L−1 of Cr(VI) with 24 hours of equilibration time and 2.50 g L−1 of dose of biomaterial at room temperature. The sorption efficiency was found to be better than many charred bio-based materials.

scholarly journals Dysprosium Removal from Water Using Active Carbons Obtained from Spent Coffee Ground

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1372 ◽  
Author(s):  
Lorena Alcaraz ◽  
María Esther Escudero ◽  
Francisco José Alguacil ◽  
Irene Llorente ◽  
Ana Urbieta ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Potassium Hydroxide ◽  
Activated Carbons ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Microporous Material ◽  
Spent Coffee Ground ◽  
Coffee Ground ◽  
Pseudo Second Order

This paper describes the physicochemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. Potassium hydroxide (KOH)-activated carbon is a microporous material with a specific Brunauer–Emmett–Teller (BET) surface area of 2330 m2·g−1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g−1. A significant dependence of the adsorption capacity on the solution pH was found, but it does not significantly depend on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g−1 and 33.52 mg·g−1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better a fit to the Langmuir model and pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption onto both activated carbons is an exothermic, spontaneous, and favorable process.

THE RELATIVE ENTHALPIES OF CONCENTRATED POTASSIUM HYDROXIDE SOLUTIONS

1960 ◽  
Vol 38 (1) ◽  
pp. 57-60 ◽  
Author(s):  
Wendell J. Biermann
Keyword(s):  
Hydrochloric Acid ◽  
Potassium Hydroxide ◽  
Concentrated Solutions ◽  
Relative Enthalpy ◽  
Better Than ◽  
Enthalpy Data

Measurements were made of the heats of neutralization of concentrated solutions of potassium hydroxide with hydrochloric acid, with an estimated accuracy better than one part per thousand. From this information it was possible to calculate relative enthalpy data for potassium hydroxide solutions up to 16 molal.

scholarly journals Mespilus germanica (MG) and Tribulus terrestris (TT) Used as Biosorbents for Lead Removal from Aqueous Solutions: Adsorption Kinetics and Mechanisms

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Majid Ehteshami ◽  
Hamidreza Zolfaghari ◽  
Marjan Salari ◽  
Ehsan Teymouri
Keyword(s):  
Aqueous Solutions ◽  
Correlation Coefficient ◽  
Lead Removal ◽  
Tribulus Terrestris ◽  
Optimum Conditions ◽  
Effective Parameters ◽  
Lead Adsorption ◽  
Proposed Model ◽  
Central Composite ◽  
Solution Volume

Today, most countries around the globe are facing water resources restrictions, and it is predicted freshwater resources will be more valuable than oil wells in the next century. In the present study, the ability of lead removal using both powders of Mespilus germanica (MG) and Tribulus terrestris (TT) seeds and optimization of the adsorption process have been investigated. Four main parameters were selected for experimental design, namely, pH, time of contact, the ratio of adsorbent to solution volume, and initial concentration of lead in solution, and the optimization of effective parameters on lead adsorption was performed based on central composite design (CCD) under response surface methodology (RSM). According to the statistical results, the proposed model for MG and TT is confirmed with 0.95 and 0.96 correlation coefficient and 0.92 and 0.94 adjusted correlation coefficient, respectively. The results of parameter optimization also showed that both adsorbents have the acceptable ability to adsorb lead from aqueous solutions. Under the optimum conditions with the initial lead concentration of 10 mg/l, MG powder had better performance in lead adsorption of 96.04%, and TT powder also had an acceptive performance of 93.20%. Moreover, the MG and TT adsorbents have the most accordance with the Freundlich and D-R isotherms, respectively.

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