Adsorption of o-Nitrophenol (o-Nph), m- Nitrophenol (m-Nph) and p- Nitrophenol (pNph) on the sedimentary sand of the Tigress River which is known locally by “Zemeej†from aqueous solution at 288, 298, 308, 318 and 328 k0 . This study indicates that o-Nph and mNph take multi-layered S type according to Giles classification while p-Nph takes a multilayered L type according to the same classification. The isotherms treated by Freundlich model and show a good response to this model because the heterogeneous nature of the surface. The adsorption for all materials was endothermic as shown from ΔH values and explained through the porous nature of the surface, the remaining thermodynamic functions ΔG and ΔS were also calculated at all temperatures for all adsorbents which indicate that the randomness, finally the results indicate that the orientation on NO2 group to para position acts to decrease the quantity of adsorption
In this article, the adsorption of Cu(ll) ion from aqueous solution into polyacrylic acid
(PAA) hydrogel bead has been investigated using a batch method of different
temperature (10-30 °C) and different contact time (1-48 hr) to reach the equilibrium of
adsorption. Initial concentration and adsorption capacity of the adsorbents is presented,
the time required to reach a maximum capacity of bead was about 24hr. The temperature
effect on adsorption was studied and the experimental data have been analyzed using the
Langmuir and freundlich isotherm models. The adEsorption capacity at equilibrium was
found to be 142.68 mg/g; more than 95% of studied cation was removed by the
adsorbent. The process is very efficient es
Wheat straw was modified with malonic acid in order to get low cost adsorbent have a good ability to remove copper and ferric ions from aqueous solutions, chemical modification temperature was 120°C and the time was 12 h. Parameters that affect the adsorption experiments were studied and found the optimum pH were 6 and 5 for copper and iron respectively and the time interval was 120 min and the adsorbent mass was 0.1 g. The values for adsorption isotherms parameters were determined according to Langmuir [qmax were 54.64 and 61.7 mg/g while b values were 0.234 and 0.22 mg/l] , Freundlich [Kf were 16.07 and 18.89 mg/g and n were 2.77 and 3.16], Temkin [B were 0.063 and 0.074 j/mol and At were 0.143 and 1.658 l/g] and for Dubinin-Radushkev
... Show MoreModified bentonite has been used as effective sorbent material for the removal of acidic dye (methyl orange) from aqueous solution in batch system. The natural bentonite has been modified using cationic surfactant (cetyltrimethyl ammonium bromide) in order to obtain an efficient sorbent through converting the properties of bentonite from hydrophilic to organophilic. The characteristics of the natural and modified bentonite were examined through several analyses such as Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Surface area. The batch study was provided the maximum dye removal efficiency of 88.75 % with a sorption capacity of 555.56 mg/g at specified conditions (150 min, pH= 2, 250 rpm, and 0.
... Show MoreCetyl trimethyl ammonium bromide (CTAB), was used as surfactant to enhance
the removal of Congo- red (C-R) dye from its solution by employing a wood of
buckthorn tree as a low cost and eco-friendly adsorbent. Different factors affecting
the sorption process like, time of adsorption, wood dose, initial (C-R) concentration
and hydrogen ion concentration have been studied for both adsorbent wood (W) and
modified wood (MW). The suitability of the two isotherm models Langmuir and
frundlich to the equilibrium results was mentioned for the adsorption of (C-R) on
both wood and modified wood. From the value of correlation - factor, frundlich
model give a better fit than Langmuir isotherm model. Thermodynamic function
su
mixtures of cyclohexane + n-decane and cyclohexane + 1-pentanol have been measured at 298.15, 308.15, 318.15, and 328.15 K over the whole mole fraction range. From these results, excess molar volumes, VE , have been calculated and fitted to the Flory equations. The VE values are negative and positive over the whole mole fraction range and at all temperatures. The excess refractive indices nE and excess viscosities ?E have been calculated from experimental refractive indices and viscosity measurements at different temperature and fitted to the mixing rules equations and Heric – Coursey equation respectively to predict theoretical refractive indices, we found good agreement between them for binary mixtures in this study. The variation of th
... Show Morecharge transfer complex formed by interaction between the p- aminodiphenylamine (PADPA) as electron donor with iodine as electron acceptor in ethanol at 250C as evidenced by color change and absorption. The spectrum obtained from complex PADPA – Iodine shows absorptions bands at 586 nm. All the variables which affected on the stability of complex were studies such as temperature, pH, time and concentration of acceptor. The linearity of the method was observed within a concentration rang (10–165) mg.L-1 and with a correlation coefficient (0.9996), while the molar absorbitivity and sandell sensitivity were (4643.32) L.mol-1.cm-1 and (0.0943) μg.cm-2, respectively. The adsorption of complex PADPA–I2 was studied using adsorbent surfaces
... Show MoreThis research includes new series of polymers were synthesized starting from polymerization of poly maleic anhydride (3), which were mono esterfication with absolute methanol to give polymer (4 ), then the acid side chlorination with thionyl chloride to give polymer (5) , which was subjected to esterfication with two different protected sugar moiety (1 and 2 ) to afford modified polymers (6 and 7). Furthermore the hydrazide polymers ( 8 and 9) were prepared through addition of hydrazine hydrate to polymers ( 6 and 7 ), which upon condensation with different free mono saccharides to give the target polymers( 10-13) respectively. The prepared polymers identified by physical properties and spectral methods (FT-IR ,1H-NMR,13C-NMR) .
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This work was conducted to study the oxidation of phenol in aqueous solution using copper based catalyst with zinc as promoter and different carrier, i.e. γ-Alumina and silica. These catalysts were prepared by impregnation method.
The effect of catalyst composition, pH (5.6-9), phenol to catalyst concentration ratio (2-0.5), air feed rate (30-50) ml/s, stirring speed (400-800) rpm, and temperature (80-100) °C were examined in order to find the best conditions for phenol conversion.
The best operating conditions which lead to maximum phenol conversion (73.1%) are : 7.5 pH, 4/6 phenol to catalyst concentration, 40 ml/s air feed rate, 600 rpm stirring speed, and 100 °C reaction temperature. The reaction involved an induction period