Adsorption
Adsorption of Diclofenac From Aqueous Solution Using Cyclamen Persicum Tubers based Activated Carbon (CTAC)
Mon, 2015-01-12 14:35 — Shehdeh JodehThis study aims to use the tissues of Cyclamen persicum
tubers to prepare activated carbon (CTAC) by different methods then to set up a
thermodynamic study of the pharmaceutical diclofenac sodium (DCF) adsorption
from aqueous solution onto this activated carbon. Optimum percent of DCF
removal was 72 % when CTAC dosage was 0.25 g and DCF concentration 50 mg/L.
Percentage removal of DCF increases when the concentration of DCF increases as
the maximum percentage removal reached 81 % when DCF concentration was 70 mg/L
and 0.7 g CTAC and pH ranging from 6 to 2.
Freundlich model describes efficiently adsorption isotherm of DCF onto CTAC
with n equal to 1.398 which value indicates a favorable adsorption. This
finding validates the assumption of multilayer physical adsorption process of
DCF. The results showed that DCF was physically adsorbed onto CTAC, as
confirmed by the values of ΔH° minor than 40 Kj/ mol. As ΔG° had negative
charge, the adsorption process is exothermic, and the adsorption process of the
DCF onto CTAC is spontaneous, depending on temperature.
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Treatment of Olive Mill Based Wastewater By Means of Magnetic Nanoparticles: Decolourization, Dephenolization and COD Removal
Tue, 2014-11-25 15:35 — Shadi Husni SawalhaOlive mill wastewater (OMW) is an environmental concern that has been highlighted as a serious environmental problem in the Mediterranean basin countries because of its high organic load and phytotoxic and antibacterial phenolic compounds, which resist biological degradation. Consequently, this type of wastewater represents a huge challenge for the conventional wastewater treatment techniques as it can impact the lifetime of bacteria needed for the treatment. Iron-oxide nanoparticles are attractive for wastewater treatment for two important reasons. First, nanoparticles can remove pollutants from wastewater rapidly. Second, this magnetic type of nanoparticles could be separated easily using a magnet after finishing treatment process. In this study, we aimed at investigating the effectiveness of the magnetic iron oxide nanoparticles in the removal of large organic contaminants from OMW. Batch and continuous mode processes were applied on OMW treatment to determine the effect of contact time, solution pH, coexisting contaminants and the adsorption isotherm.The results showed that the adsorption was fast and the adsorption reached equilibrium within less than 30 min. The adsorption equilibrium data fit very well to the Brunauer–Emmett–Teller (BET) Model, indicating multi-layers adsorption. The adsorption of major pollutants was associated to an efficient removal of coexisting contaminants such as heavy metals and free ions. The adsorption of OMW pollutants was dependent on pH of the solution. Finally, continuous-mode process was tested successfully using a packed bed column that combined sand filtration with magnetic nanoparticles to decolourize OMW effluent. This study will provide valuable insight on the effect of nanoparticles toward the treatment and recyclability of olive mill wastewater, which is crucial for the local olive mill industry. After seeing the successful achievement of integrating nanoparticles with fixed bed filtration, a preliminary process description and cost estimation of stand-alone plant (with a capacity of 4 m3/h) for OMW treatment were considered in this study. Process capital and annual operating costs were estimated to be $12,306 and $476/year, respectively.
Adsorption of Some Organic Phenolic Compounds Using Activated Carbon From Cypress Products
Thu, 2014-10-09 13:43 — Shehdeh JodehPhenolic organic compounds are extremely highly generated from many resources which disposed to sewerage system without treatments that increase the risk of contaminating water resources. This study is focused on preparing and studying the properties of activated carbon produced from cypress fruit by chemically activation using phosphoric acid (H 3 PO 4) as an activating agent. The activated carbon used to adsorb p-nitrophenol (PNP) from the aqueous solution. Result show that the activated carbon produces from cypress fruit gives good percentage yields which reach up to 51.8%. Surface area determined by iodine number showed 524.1m 2 /g. The adsorptive properties of CFAC were investigated in terms of adsorbent dose, PNP concentration, pH, and temperature and contact time in a batch system. Results indicate that the optimum percent of PNP removal 90.9 % when adsorbent dosage 0.3g and PNP concentration 80mg/L and percentage removal of PNP increase when the concentration of PNP decrease which maximum percentage removal reach 93.2% when PNP concentration 20mg/L and 0.1g CFAC. The effect of temperature on adsorption by CFAC has also been investigated in the range of 15-45 °C. The results indicate that the temperature slightly affected effectiveness of CFAC adsorption. The results showed that equilibrium time for PNP adsorption is 150min, but most the adsorption attained within the first ten minute. Results investigate that the produced cypress fruit activated carbon (CFAC) adsorption equilibrium is represented by both Frenundlich and Langmuir equilibrium model, but Langmuir model describe very well the adsorption. The main properties of Langmuir equation can be expressed in term of separation factor, R L . The R L equal 0.053 that indicate the adsorption favorable.
Inhibitive Action of Hydroxylammonium Sulfate on the Corrosion of Carbon Steel in Hydrochloric Acid Medieum and their Adsorption Characteristics
Thu, 2014-10-09 13:32 — Shehdeh JodehThe inhibitive action of Hydroxylammonium sulfate ((NH3OH)2SO4) (HAS) on corrosion inhibition of carbon steel (CS) in 1M HCl was studied by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and effect of temperature. The measurements show that inhibition efficiencies increases with increasing of HAS concentrations but decreases with increasing temperatures. This reveals that inhibitive action of inhibitor was mainly due to adsorption on the carbon steel surface and blocked the active sites. The above results showed that HAS acted as a mixed-type corrosion inhibitor. The adsorption of HAS on the carbon steel surface obeyed the Langmuir adsorption isotherm. This was supported by the impedance measurements which showed a change in the charge transfer resistance and double layer capacitance indicating adsorption of HAS on the carbon steel surface. Thermodynamic parameters of studied inhibitor were calculated and discused.
Fate and Mobility of Glyphosate Leachate in Palestenian Soil Using Soil Columns
Thu, 2014-10-09 12:44 — Shehdeh JodehIn recent years, pesticides were used heavily in Palestine,
which led to the contamination of soil and water and causing many diseases.
Many studies focused on the impact of pollutants such as pesticides and oil on
soil, humans, animals, plants and the environment in general.
Using column study the amount of glyphosate in soil decreases with increasing
depth of soil, where it is for 0-30cm(11ppm) > 30-60cm(6ppm) >
60-100cm(2ppm) due to organic content and metal oxides founded in soil that can
form stable complexes with glyphosate.
When we increased the concentration of glyphosate, the amount of glyphosate
(contaminant) in leachate where found to be 25x (15.96ppm) >15x (3.91) >
5x (3ppm) column.
The behavior of glyphosate leachate fits the first order reaction and the
isotherm is in according with the Freundlich adsorption equation with R2 value
0.98, k value 6.4 and n value 1.07 which indicates good adsorption to soil.
Comparative Oxidation of Adsorbed Asphaltenes onto Transition Metal Oxide Nanoparticles
Mon, 2014-05-19 12:46 — Nashaat N. NassarIn this study asphaltenes – waste hydrocarbons and problematic constituent present in heavy oil – have been investigated for its oxidation onto different types of nanoparticles, namely NiO, Co3O4 and Fe3O4. All nanoparticles tested showed high adsorption affinity and catalytic activity for asphaltene adsorption and oxidation in the following order NiO > Co3O4 > Fe3O4. The oxidation temperature of asphaltenes decreased by 140, 136 and 100 °C with respect to non-catalytic oxidation in the presence of NiO, Co3O4, and Fe3O4nanoparticles, respectively. A correlation appears to exist between the adsorption affinity and the catalytic activity, the higher the affinity the greater the catalytic activity.
Effect of Surface Acidity and Basicity of Aluminas on Asphaltene Adsorption and Oxidation
Mon, 2014-05-19 11:55 — Nashaat N. NassarThis study investigates the effect of surface acidity and basicity of aluminas on asphaltene adsorption followed by air oxidation. Equilibrium batch adsorption experiments were conducted at 25 °C with solutions of asphaltenes in toluene at concentrations ranging from 100 to 3000 g/L using three conventional alumina adsorbents with different surface acidity. Data were found to better fit to the Freundlich isotherm model showing a multilayer adsorption. Results showed that asphaltene adsorption is strongly affected by the surface acidity, and the adsorption capacities of asphaltenes onto the three aluminas followed the order acidic > basic and neutral. Asphaltenes adsorbed over aluminas were subjected to oxidation in air up to 600 °C in a thermogravimetric analyzer to study the catalytic effect of aluminas with different surface acidity. A correlation was found between Freundlich affinity constant (1/n) and the catalytic activity. Basic alumina that has the lowest 1/n value, depicting strongest interactions, has the highest catalytic activity, followed by neutral and acidic aluminas, respectively.
Kinetics, Equilibrium and Thermodynamic Studies on the Adsorptive Removal of Nickel, Cadmium and Cobalt from Wastewater by Superparamagnetic Iron Oxide Nanoadsorbents
Mon, 2014-05-19 10:52 — Nashaat N. NassarBecause of its unique properties, such as specific functionality and large specific surface area, iron oxide nanoadsorbents had showed potential for energy and environmental applications. This work investigated the adsorptive removal of different metal ions from wastewater by superparamagnetic iron oxide nanoadsorbents (Fe3O4). Batch-adsorption technique was employed to assess the kinetic behaviour and adsorption equilibrium of cadmium, cobalt and nickel. Accordingly, the effect of the following variables on the adsorption reaction was tested, namely: solution pH, contact time and temperature. Metal ion adsorption was found to be highly pH dependent with a maximum uptake achieved around pH 5.5. Kinetic studies showed that adsorption was fast and equilibrium was achieved in less than 60 min. The external mass transfer kinetic model was applied to the experimental results and provided reasonable overall volumetric mass transfer coefficients. Adsorption isotherms were determined and appropriately described by the Freundlich and Langmuir models, with a better fit to the Freundlich model. The amount of metal ion adsorbed increased as the temperature increased, suggesting an endothermic adsorption process. The thermodynamics studies indicated that the adsorption process was spontaneous and endothermic in nature. © 2011 Canadian Society for Chemical Engineering
Thermogravimetric Studies on Catalytic Effect of Metal Oxide Nanoparticles on Asphaltene Pyrolysis Under Inert Conditions
Mon, 2014-05-19 10:36 — Nashaat N. Nassar
Impacts of Biodegradable Organics on Soils and Groundwater in West Bank
Wed, 2014-04-02 07:47 — Marwan N. HaddadThe purpose of this study was to investigate the impact of biological oxygen demand (BOD) on soil and drinking water in West Bank. This study will give us a conclusion about ground water contamination from solid waste and sewage water. The study was performed on two soil samples brought from Jericho and Talkarem. The physical and chemical properties of the two soil samples were analyzed. The experiment was studied using physical simulation by using different soil column techniques and making some estimation using the amount of rainfall each year and the dimensions of those columns. The study was conducted between April and May, 2009. The concentration of BOD in the leachate was found to increase with time in both types of soil, in April the BOD concentration was higher in the leachate from Jericho soil than Talkarem soil, but in May the BOD concentration was higher in Talkarem soil than Jericho soil. The concentration of BOD in the leachate collected from blank column was decreasing with time, the dissolved oxygen (DO) was decreasing with increasing BOD concentration in both soils. The total dissolved solids (TDS) concentration in the leachate was decreasing in both soils with time. The BOD concentration was increasing in the soil layers from top to the bottom in both soils (Talkarem and Jericho), but BOD was higher in Talkarem soil in each layer compared with that in Jericho soil layers. The TDS level in Talkarem soil layers was higher than in Jericho soil layers. The total nitrogen (TN) concentration in soil layers increases with depth and with time during water addition in the blank column but decreases in the soil layers in the columns where BOD was added.
