Adsorption of Humic Acid from Aqueous Solution onto PVDF Nanofiber: Effect of Temperature

2016 ◽  
Vol 863 ◽  
pp. 123-126 ◽  
Author(s):  
Muhammad Ali Zulfikar

The sorption of humic acid from aqueous solution onto polyvinyl difluoride nanofiber under the influence of temperature has been investigated. Batch adsorption experiments were carried out using humic acid (HA) as an adsorbate. It was observed that the amount of humic acid adsorbed increase with increasing temperature. Thermodynamic parameters data indicated that the humic acid adsorption was non-spontaneous and endothermic under the experimental conditions, with the enthalpy (∆H) and entropy (∆S) of +16.32 kJ mol-1 and +41.92 J mol-1, respectively.

2019 ◽  
Vol 811 ◽  
pp. 99-103
Author(s):  
Muhammad Ali Zulfikar ◽  
D. Maulina ◽  
Henry Setiyanto ◽  
Muhamad Nasir

The potential of polyacrylic acid (PAA) nanofiber prepared by the electrospinning technique for the humic acid (HA) adsorption from aqueous solution was investigated. In this study, the adsorption experiments were carried out to investigate the effect of temperatures in a batch system. From experiment it can be seen that the HA adsorption using PAA nanofiber increased with increasing temperature. Thermodynamic parameters data indicated that the HA adsorption process was non-spontaneous and endothermic under the experimental conditions, with the Gibbs free energy (∆Go) in the range of 1.721-0.980 kJ mol-1, enthalpy (∆Ho) and entropy (∆So) of 7.24 kJ mol-1 and 18.52 J mol-1 K-1, respectively.


2007 ◽  
Vol 28 (2) ◽  
pp. 295-300 ◽  
Author(s):  
Leonardo Vignoli ◽  
Marco Bologna ◽  
Manuela D'Amen

AbstractAmphibian populations are especially sensitive to aquatic parameters, in particular during embryonic and larval life. Our aim was to test for an effect of temperature (T = 13°C, 20°C and 25°C at constant pH = 7) and pH (pH = 5.5, 7 and 8.5 at constant T= 20°C) on embryos of two species of Triturus, T. carnifex carnifex and T. italicus (Amphibia, Salamandridae) using GLM procedure. Trend of embryogenesis processes, time to hatching and rate of development have a similar effect in both species in the used range of temperature and pH. Time to hatching decreased significantly with the increasing temperature. The pH experimental conditions had no effect on T. carnifex embryos survival, while the acidic pH condition raised the mortality rate in T. italicus, whose embryos should be more vulnerable than those of T. carnifex to acidification in nature.


2012 ◽  
Vol 706-709 ◽  
pp. 768-773
Author(s):  
Masahiro Nishida ◽  
Koichi Hayashi ◽  
Junichi Nakagawa ◽  
Yoshitaka Ito

The influence of temperature on crater formation and ejecta composition in thick aluminum alloy targets were investigated for impact velocities ranging from approximately 1.5 to 3.5 km/s using a two-stage light-gas gun. The diameter and depth of the crater increased with increasing temperature. The ejecta size at low temperature was slightly smaller than that at high temperature and room temperature. Temperature did not affect the size ratio of ejecta. The scatter diameter of the ejecta at high temperature was slightly smaller than those at low and room temperatures.


2008 ◽  
Vol 10 (2) ◽  
pp. 43-49 ◽  
Author(s):  
Mohammed Uddin ◽  
Mohammed Islam ◽  
Mohammed Islam ◽  
Mohammed Abedin

Uptake of phenol from aqueous solution by burned water hyacinth The potential of burned water hyacinth (BWH) for phenol adsorption from aqueous solution was studied. Batch kinetic and isotherm studies were carried out under varying experimental conditions of contact time, phenol concentration, adsorbent dosage and pH. The pH at the point of zero charge (pHPZC) of the adsorbent was determined by the titration method and the value of 8.8 ± 0.2 was obtained. The FTIR of the adsorbent was carried out in order to find the potential adsorption sites for the interaction with phenol molecules. The Freundlich and Langmuir adsorption models were used for the mathematical description of adsorption equilibrium and it was found that the experimental data fitted very well to the Langmuir model. Maximum adsorption capacity of the adsorbent was found to be 30.49 mg/g. Batch adsorption models, based on the assumption of the pseudo-first-order and pseudo-second-order models, were applied to examine the kinetics of the adsorption. The results showed that kinetic data closely followed the pseudo-second-order model.


Author(s):  
Jesús E. Hernández ◽  
José Luis Palazón-Fernández ◽  
Gonzalo Hernández ◽  
Juan Bolaños

Larvae of Stenorhynchus seticornis were reared in the laboratory in a factorial experiment employing three temperatures (22, 25 and 28°C) and three salinities (30, 35 and 40‰) to determine the effects of these variables on the survival and duration of the larval stages. Larvae from five females were subdivided in six groups of 10 and reared in glass bowls containing 125 ml filtered and UV-irradiated seawater at different temperature–salinity combinations. Larvae were transferred daily to clean bowls with newly hatched Artemia nauplii, and the number of moults and mortality within each bowl was recorded. Complete larval development of S. seticornis occurred under all experimental conditions, except at temperature 28°C and salinity 35‰. Salinity affected percentage survival of the two zoeal stages, but not that of the megalopa. Survival of the second zoeal stage, the megalopa, and the complete development to the first crab was affected by temperature, with the greatest survival occurring at 25°C. Duration of the two zoeal stages, the megalopa, and development to the first crab stage showed a gradual reduction with increasing temperature. Development from hatching to the first crab stage required 17 to 31 days and was inversely related to temperature, averaging 26.9 days at 22°C, 21.0 days at 25°C and 19.7 days at 28°C. Salinity affected the duration of the first zoeal stage only.


2011 ◽  
Vol 233-235 ◽  
pp. 1972-1980 ◽  
Author(s):  
Yu Bin Tang ◽  
Fang Yu ◽  
Fang Yan Chen ◽  
Cheng Chen

Rectorite (REC), humic acid (HA) and polyvinyl alcohol (PVA) were used to prepare microspheres. Batch adsorption experiments of Pb2+ion on to the microspheres were performed. The results obtained indicate that adsorption time, the microspheres dosage and temperature were the main factors influencing the adsorptive capacities. The adsorption data for Pb2+ion were well described by the Freundlich, Langmuir and Temkin models. The kinetic experimental data properly correlated with the pseudo-first-order model, pseudo-second-order model and Elovich equation. The adsorption process is spontaneous, endothermic and out-of-order. The whole adsorption process is mainly controlled by entropies. The adsorption can be classified as chemical adsorption. The mechanisms for the adsorption of Pb2+ion on to the microspheres involved ion-exchange adsorption of Pb2+or the formation of complex compound. Under the experimental conditions employed, the removal of Pb2+ion attained value of 96.05%.


2015 ◽  
Vol 12 (6) ◽  
pp. 3996-4008
Author(s):  
Hussein A Mohamed ◽  
Magdy A Wassel ◽  
Rabie S Farg ◽  
Hassan A Shehata ◽  
Aamal M Anwar

The object of this study is to assess the removal of Fe(III) ions from aqueous solutions onto modified chitosan. The effect of various parameters has been investigated by the following batch adsorption technique. The various variables studied include initial concentration of the adsorbate, agitation time, adsorbent dosage, kinetics, influence of temperature. The experimental data was fit well to the Freundlich isotherm. Thermodynamic parameters such as ΔH, ΔS and ΔG were calculated, indicating that the adsorption was spontaneous and endothermic nature.


2018 ◽  
Vol 3 (1) ◽  
pp. 13
Author(s):  
Muhammad Ali Zulfikar ◽  
Afdal Bahri ◽  
Muhamad Nasir

<p>The main objective of this study is to investigate the isotherm sorption of humic acid (HA) from aqueous solution onto dual nanofiber PMMA/PVDF. Batch adsorption experiments were carried out using HA solution as an adsorbate under variety of concentration in the range of 50-200 mg/L. The experimental data were analyzed by the Langmuir, Freundlich and Sips models of adsorption. The experimental results indicate that, the adsorption capacity of HA adsorption increases with an increase in the HA concentrations. The adsorption of HA onto dual nanofiber PMMA/PVDF agrees well with the Langmuir isotherm models with the maximum adsorption capacity was found to be 137.40 mg g<sup>-1</sup> at concentration of 100 mg L<sup>-1</sup>.</p>


2016 ◽  
Vol 12 (2) ◽  
pp. 3996-4008
Author(s):  
Hussein A Mohamed ◽  
Magdy A Wassel ◽  
Rabie S Farg ◽  
Hassan A Shehata ◽  
Aamal M Anwar

The object of this study is to assess the removal of Fe(III) ions from aqueous solutions onto modified chitosan. The effect of various parameters has been investigated by the following batch adsorption technique. The various variables studied include initial concentration of the adsorbate, agitation time, adsorbent dosage, kinetics, influence of temperature. The experimental data was fit well to the Freundlich isotherm. Thermodynamic parameters such as ΔH, ΔS and ΔG were calculated, indicating that the adsorption was spontaneous and endothermic nature.


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