Agricultural Based Low Cost Absorbnts

Agricultural Based Low Cost Absorbnts
AGRICULTURAL BASED LOW COST ABSORBNTS
Dr.K.Muthukumaran1, S.Sugumar 2 R.Gokulkarthik3, D.Kaviyarasu4, Department of chemistry, 2,
3, 4. Department of Environmental Engineering Section.
Government College of Technology, Coimbatore 13.
Abstract Adsorption is one of the preferred techniques in recent years to remove the color and
inorganics from waste water. Activated carbon derived from the agricultural byproduct, acts as an
effective adsorbent for the removal of dyes from waste water. The removal of dyes and metal ions at
different, contact time, bed height, flow rate, initial dye concentration, column diameter, adsorbent
dosage, pH, and temperature by different agriculture based adsorbent has been studied. The result
shows that among the compared adsorbents, moringa oleifera derived adsorbent is effective for
waste treatment. The adsorption data were well fitted by Freundlich–isotherm model. Kinetic data
were best described by pseudo–second order model.
Keywords: Adsorption, agriculture waste, dye, metal ions.
1. Introduction
Pollution has been a wide problem in all over a world. In most of the industries used dyes as a
coloring agent such astextile (Y.C. Wong et al., 2013), paint (King et al., 2008), leather (Sugashini
S. et al., 2012), cosmetic (Suantakkamsonlian et al., 2011),paper, printing, cloth (George Z. Kyzas)
andfood industries. The wastewaters discharged from dying industries which contains high
biological oxygen demand (BOD),
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What Are Pfcs? ( Property And Applications )
What are PFCs? (Property and Applications)
Perfluorinated compounds (PFCs) are a group of manmade organfluorine chemicals, containing a
chain of carbon atoms surrounded by C–F bonds often with a charged functional group in the end.
The fluoroalkyl chain normally exhibit hydrophilic property, while the typical functional group such
as sulfonate salt or acid tends to be hydrophobic. These unique characteristics make the compound
oil and water repellent at the same time, which contributes to the widely application in the industrial
and domestic products: upholstery, textiles, carpet, lubricants, foam in fire extinguishers, water
repellents for paper, and others. In turn PFCs enter the environment through various ways. On the
other hand, due to the low molecular polarizability fluoroalkyl chains, short yet very strong C–F
bonds, PFCs are very resistant against chemical as well as biological degradation, which make them
extremely persistent in the environment.
How harmful are they? (Toxicity Assessment)
The varieties use and widely existence of PFCs has posed certain environmental risks to the
ecosystems and human. Toxicity studies to date have been limited mainly to the dominant
compounds detected in the environment, such as perfluorooctanesulfonate (PFOS) and
perfluoroocanoic acid (PFOA).Their toxicities to varieties of organisms have been investigated and
indicated that PFCs can have several adverse effects in organisms to some extent, such as bacteria
(Rosal et al., 2010),

Differential Kinetics And Error Analysis
3.6.3. Adsorption kinetics and error analysis
It is known that converting the non–linear regression to linear form of most kinetic models may lead
to positive or negative effect on determining the kinetic parameters of the adsorption process [34].
In this study non–linear and linear regression (using software Origin 8.6)of pseudo first–order,
pseudo second–order and Elovich kinetic models(Table 1) were used to investigate the kinetic sand
the best fit model for the uptake of MB by ZnO/CR powder at different temperatures(10, 20, 30 and
40 °C).In addition different statistical error analysis functions such as , and SSE (equations 13 – 15)
were used to evaluate the validity of the used models and to investigate the mechanism of the
adsorption process.
3.6.3.1. Effect of converting non–linear to linear form of kinetic models
Kinetic parameters of adsorption of MB onto ZnO/CR Hence the adsorption rate of MB onto
ZnO/CR is proportional to the concentration of MB sorbed, non–linear and linear Lagergren 's
pseudo first–order (equations6 and 7) can be used to calculate the kinetic parameters. The
experimental data of adsorption of MB onto ZnO/CR were treated by the non–linear equation of
pseudo first–order (using fitting function builder of Origin software) to estimate the values of and
from the plot of versus (Figure 9a).Then the values of converted to and plotted versus according to
the linear equation of pseudo first–order equation to calculate the values of and

Working Principle Of The Hybrid Adc System
Working principle of the hybrid ADC system
AD cycle consists of four processes as shown in Fig. 4. These processes are: Isosteric heating
process (1 2): adsorption pair is heated without changing initial adsorbate concentration (C_i ).
Isobaric desorption process (2 3): adsorption pair is heated up with changing adsorbate
concentration from C_i to final concentration (C_f ). On the other side, the desorbed water vapor is
condensed in condenser releasing heat of condensation at condenser temperature〖 (T〗_cond).
Isosteric cooling process (3 4): adsorbent material is cooled down without changing adsorbate
concentration at〖 C〗_f. Isobaric adsorption process (4 1): the adsorbent adsorbs vapor at
evaporator pressure P_evap. In this process, the adsorbate concentration is increased from C_f to
C_i and releasing heat of adsorption. The adsorbate is evaporated and producing a cooling effect in
the evaporator.
The procedure used in conducting the experiments is;
Fig. 5 (a, b) shows the two beds hybrid ADC system. It consists of three main parts, two beds,
evaporator and condenser. The two beds are working alternately. As shown from Fig. 5 (a), in bed 1
desorption process is occurred while in bed 2 adsorption process is occurred. After half cycle time,
in bed 1 adsorption process is occurred while in bed 2 desorption process is occurred as illustrated
in Fig. 5 (b).
After evacuating system, the de–aerated sea water is pumped intermittently into the evaporator
where the

Dyeing Studies of Wool Fibers with Madder
In this study, the dyeing behavior of wool fabrics with madder has been studied. Also, the effect of
different mordants (potassium dichromate, stannous chloride, alum, ferrous sulphate, lime, copper
(I, II) sulphate, cobalt chloride, and nickel chloride) as well as three mordanting procedures namely
pre–, meta– and post–mordanting on color characteristics of the dyed samples has been investigated.
The adsorption isotherm of madder on wool fibers was found to follow Freundlich type of
adsorption. The addition of salt and acid (pH 4.5) to the dyebath resulted in an increase of
adsorption. In relation to mordanting tests, the use of different mordants and mordanting procedures
gave various color characteristics on dyed wool fabrics. The results showed that all the dyed
samples, mordanted and unmordanted, were in the first quadrant of CIEL*a*b* color space.
Mordants such as potassium dichromate, ferrous sulphate and copper (I, II) sulphate led to the
darker and lower chromaticity compared to unmordanted dyed sample while mordants stannous
chloride, alum resulted in the lighter and higher chromaticity values. Mordanting with the chlorides
of cobalt and nickel showed the minimal color difference (∆E) with the unmordanted dyed sample.
The fastness properties indicated that in general wash and light fastness of the mordanted samples
were higher than the unmordanted one.
Key words: wool, madder, mordant, fastness properties, natural dye.
Introduction:
The use of natural dyes for

Removal Of Phenol From Aqueous Solution Using Duolite A 171
Removal of phenol from aqueous solution using Duolite–A–171
Duolite–A–368 plus and Duolite–S–861 polymeric resins
A.K.R. VasanthaKamesh, M. Pandeeswaran*, G.N. kousalya and S. Kannan
PG and Research Department of Chemistry, GTN Arts College, Dindigul, Tamilnadu, India
Abstract
The removal of phenol from aqueous solution was evaluated by batch method using two ion
exchange resins, Duolite–A–171 (DLE–171) (a strong anion exchange resin) and Duolite–A–368
plus (DLE–368) (a weak anion exchange resin) and a nonfunctionalized Duolite–S–861 (DLE–861)
resin. The maximum removal capacity was achieved at pH 11. The removal of phenol was found to
be in the following order DLE–171 > DLE–368 > DLE–861. The mechanism involved in the
process was found to be both adsorption and ion exchange. The resin was characterized using FTIR
and SEM with EDAX analysis. The equilibrium data were fitted to Freundlich isotherm. The
kinetics of the sorption was found to follow pseudo–second–order and intraparticle diffusion
models. The values of thermodynamic parameters indicate the nature of sorption is spontaneous and
exothermic.
Keywords: Removal of Phenol; Polymeric Resins; Duolite–A–171; Duolite–A–368; Duolite–S–171.
*Corresponding author
Dr. M. Pandeeswaran, Assistant Professor, Department of Chemistry, GTN Arts College, Dindigul –
624005, Tamilnadu, India.
Mobile: +91 915039138, Email id: pandeeswaran@gmail.com.
1. Introduction Heavy metals are recognized as the persistent and toxic

The Properties Of Solid Sorbents Relevant On The...
Sorbent characteristics
This chapter discusses the properties of solid sorbents relevant to the performance and cost of CO2
capture. The chapter begins with a discussion of the solid sorbent properties that are important for
CO2 capture. The discussion then broadens to include a range of factors which affect the CO2–
capture process, such as the interactions between the solid sorbent and other flue gas components,
sorbent attrition and degradation, and the influence of reaction kinetics. The chapter concludes with
a summary of ?best estimate? characteristics of the specific solid sorbents analyzed in this work.
Solid sorbent properties
Solid sorbents are small porous particles which can selectively adsorb or complex with gaseous
chemical species (in this case, CO2), thereby removing the species from a gas mixture. Molecules of
CO2 may be held loosely by weak intermolecular forces termed ?physiosorption? or strongly via
covalent bonding, termed ?chemisorption.? Generally, physiosorption occurs when the heat of
adsorption is greater than approximately –40 kJ/mol of CO2 (i.e. –20 to –40 kJ/mol), while
chemisorption occurs with the heats of adsorption less than –60 kJ/mole (Yang, 2003). These are
rules of thumb, however, and exceptions do exist. For instance, the heat of physiosorption of CO2 in
some zeolites has been reported to be as low as –210 kJ/mol CO2 (Shen, et al., 2000), with heats of
chemisorption known to extend from as low as –62 kJ/mol to over –420 kJ/mol. The heat

Weight Data And Images Showing The Physical Appearance Of...
Heat treatment
Weight data and images showing the physical appearance of the BPs are shown in Figure 3 and 4,
respectively. Acetone–cleaned AD BPs lost approximately 26, 48, and 32 % of their weight, whereas
methanol–cleaned AD BPs decreased their weight by around 29, 40, and 34 % at 300 ˚C for 90 min,
350 ˚C for 60 min, and 300 ˚C for 120 min, respectively. HiPco BPs lost about 22, 5, and 1 % at 350
˚C for 30 min, 300 ˚C for 30 min, and 250 ˚C for 30 min, respectively. However, when we
recalculated the weight change from the theoretical weight of AD BPs considering the surfactant
effect, + 5, – 25, and – 2 % weight of acetone–cleaned AD BP were changed after HT at the first
(300 ˚C – 90 min), second (350 ˚C – 60 min), and third (300 ˚C – 120 min) conditions while there
were + 5, – 13, and 0 % changes in weight for methanol–cleaned AD BPs. As a result, at the first
and third conditions, the weight change of AD BPs weight change was minimal and while for HiPco
BPs weight change was minimal at the second and the third conditions.
Methanol–cleaned AD BPs were either swirled or become brittle even before heat treatment (Figure
4). Acetone–cleaned AD BPs also showed a similar pattern but only at the first condition, the
samples keeping the physical integrity. HiPco BPs did not manifest any change in appearance or
integrity throughout the experiment and the samples were very flexible.
Characterization of Adsorption Properties
Acetone–cleaned AD BP had suface area with mean pore

Surface Chemistry of Silica
In order to gain strong insight into the surface chemistry of silica we have perform a thorough
literature search. Our goal is to identify the pioneer research performed on silica and silica
supported catalyst. Particular interest lies in silica–water–cobalt and silica–alcohol–cobalt systems.
This study is both on macro and micro level so that a complete theoretical base can be established.
From this theoretical knowledge, key areas to look upon will be identified and a design of
experiments will be established. The goal is to develop a both efficient and effective product
(catalyst) using a novel methodology developed from past research.
Silica Structure:
Fundamental studies by Stober [ ], Meyer and Heckerman [ ] , and Bering and ... Show more content
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It is also possible that this monolayer will already be present on gel even before it contacts an
aqueous solution. On the other hand, alcohol due to its vertical orientation can lead to random
distribution of vertical stacks on isolated silanol groups. The gaps between these stacks present ideal
location of solute anchorage on silica. In case of esterification (resulting from small amount of water
in alcohol) we believe that small size of ethoxy group will permit solute to find some anchorage
points on silica.
Silica–Solute Interaction (Aqueous system)
In case of dilute aqueous solution, classical models explain the interaction of solute ions with the
silica surface [ ]. As per Nernest equation work is done to transport ion from infinite distance to a
point close to surface. A diffuse "double layer" within close proximity to surface keeps ions in
motion due to thermal phonons. A proportion of these ions based on their size then enter "stern
layer", a compact immobilized layer near the surface.
Healy, James and Cooper [ ] did some pioneer work on the state of precipitated cobalt ions and their
possible interaction to silica surface. At low pH around 6 or below and low concentration, the active
specie is Co2+ swarming in diffuse double layer. Above 6.5 but well below precipitation the salt
dissolving near the surface if able to form the anchorage to the surface, the interaction may take
following form.
At pH around precipitation

Advantages And Disadvantages Of Membrane Filtration
The increased cost of water consumption and wasteful require treatment process that is integrated
with the circuits of water on the ground rather than as a subsequent treatment (19). From this point
of view, membrane filtration offers a potential application. The processes that use membranes offer
exciting possibilities for separation of dyestuffs and dyeing auxiliaries that reduce simultaneously
hydrolysed color and biochemical oxygen demand /chemical oxygen demand of wastewater;
generally used to treat effluent reactive dye bath, that could potentially reduce the volume of waste
and recovery simultaneously salt (20). On the other hand, can be separated into two or more
components the flow of fluid to its molecular size. The advantages of membrane filtration are
because, it is fast with low space requirement and saturation can be reused. The disadvantage with
membrane filtration method has a limited lifetime before it happens fouling of the membrane and
the cost is also excessive (21). The choice of the membrane process, in the case of reverse osmosis,
nanofiltration, ultra ... Show more content on Helpwriting.net ...
Maintain nanofiltration membranes of low molecular weight organic compounds, divalent ions,
large monovalent ions, Hydrolyzed reactive dyes and dyeing of auxiliaries. Harmful effects of high
concentrations of dye and salts in dye house outflows have often been reported (33, 34, 35). In most
published studies on dye waste water, the concentration of mineral salts is not more than 20 g / l and
the concentration of dye does not exceed 1.5 g / l (36). In general, the wastewater is reconstituted
with only one dye (37), and the volume studied is also low. The treatment of waste water by
nanofiltration is one of the rare applications that are possible for the treatment of solutions with
highly concentrated and complex solutions (38). An important problem is the accumulation of
dissolved solids, which eliminates the treated discharge outflows in water currents

Co2 Adsorption Capacity Is Defined As A Measure Of An...
CO2 adsorption capacity is defined as a measure of an adsorbent's capability or potential to adsorb
CO2. It is expressed in terms of number of moles of CO2 that a unit mass of an adsorbent adsorbs
under equilibrium conditions. The CO2 adsorption isotherms for MCM–41–30, MCM–41–30–AP–
9–85–0.5 and MCM–41–30–TP–9–75–0.3 at 30 °C are presented in Figure 6(a). The CO2
adsorption isotherms for amine tethered samples exhibit a steep nonlinear concave shape due to the
strong interactions between carbon dioxide molecules and amine moieties. In contrast, MCM–41–30
exhibits a less steep isotherm indicating that pure silica interacts with CO2 only by physisorption
and hence lacks sufficient strong affinity towards CO2. Therefore, it is clear that the ... Show more
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Amine efficiency provides a measure of the fraction of amine groups present in an adsorbent that
actively participate in adsorbing CO2 by chemisorption. It is reported that the theoretical maximum
value for amine efficiency that an ideal adsorbent should exhibit under dry CO2 adsorption
conditions is 0.5 (for PCO2 = 0.1–0.2) i.e., in the absence of significant physisorption at non–
functionalized sites. The amine efficiency values for MCM–41–30–AP–9 series and MCM–41–30–
TP–9 series are presented in Table 2, from which the variation in amine efficiency with respect to
amine loading can be noticed. From Table 2, it is evident that, as amine loading increases, at first
amine efficiency increases, then reaches a maximum at a critical value of amount of water added in
the reaction mixture and then finally drops off at water levels higher than the critical value for both
mono and tri aminosilane addition. The similar trend in amine efficiency is observed with respect to
increase in grafting temperature for constant amount of water, in case of both mono and tri amino
silane compounds. MCM–41–30–AP–9–85–0.5 sample exhibited the maximum amine efficiency of
~0.5, which is close to theoretical maximum value. This proves that MCM–41–30 serves as an ideal
support for amine tethering process, where the CO2 adsorption process is not hindered due to
transport/diffusion

Titanium Cerium Ferrite ( Tcf ) Was Prepared By A Simple...
Abstract Titanium cerium ferrite (TCF) was prepared by a simple solvothermal method. The
obtained TCF was applied as magnetic adsorbent for the extraction of uranium ions from aqueous
solutions. The synthesized magnetic nanoadsorbent was characterized using FT–IR, XRD, Raman,
BET surface area, VSM and TEM. Various parameters such as solution pH, initial concentration,
sorbent dosage and rate of adsorption were investigated using batch adsorption experiments. The
optimum pH was found to be 6.0 and the equilibrium was achieved in approximately 120 min.
Kinetic studies indicated that pseudo–second–order kinetic model best describes the adsorption
behavior. The adsorption isotherms were well fitted by Langmuir adsorption isotherm and the
maximum adsorption capacity was evaluated to be 555.555 mg/g at 55 ⁰C. The thermodynamic
parameters calculated from the adsorption data suggested that the adsorption of U (VI) onto TCF
was a spontaneous and endothermic nature of process. The highest values of uranium desorption
was achieved using 0.1 M HNO3 as the desorbing agent. The results indicate that TCF has potential
as an adsorbent for sorption U (VI), using a simple, fast separation method for removal of uranium
ions from aqueous solution.
1. Introduction
Uranium is one of the most dangerous heavy metals in the environment because of its chemical
toxicity and radioactivity. Excessive

The Correlation Bonding And Chemical Properties Of The As...
The nature and interlayer interactions of the as–synthesized BN materials were also characterized by
Raman spectroscopy (Figure 4b). The Raman spectra of the T–BN and F–BN show specific peaks at
∼1371 and ∼1369 cm−1, respectively, corresponding to the B–N vibration mode (E2g). The full
width at half maximum (FWHM) was determined to be ∼35 and ∼24 cm−1 for T–BN and F–BN,
respectively. The larger FWHM value and higher wavelength demonstrated a low crystalline
structure along with the low interlayer interactions at T–BN as compared to that of F–BN [32–34].
The intermolecular bonding and chemical properties of the as–synthesized BN were characterized
by FTIR spectroscopy (Figure 4c). The FTIR analysis of T–BN shows two strong absorption peaks
at ∼1382 and ∼790 cm−1, ascribed to the in–plane B–N transverse stretching vibration and the B–
N–B out–of–plane bending vibration, respectively [35–37]. The broad absorption peaks at ∼3415
and ∼3227 cm−1 indicate the presence of residual B−OH and B−NH2 groups, respectively. The
same FTIR results are also observed for F–BN. However, the higher intensity of the IR peaks of F–
BN as compared to that of T–BN indicates the existence of stronger interlayer interaction because of
the presence of more number of amino functional groups at the F–BN surface, strongly reducing the
porosity and decreasing the surface area of the F–BN materials [38]. Then, the SSA and pore size
distribution of the as–synthesized BN products were determined by nitrogen

The Effects Of Water Pollution On The World And It...
Water pollution is one of the most undesirable environmental problems in the world and it requires
solutions. Textile industries produce a lot of wastewater, which contains a number of contaminants,
including acidic or caustic dissolved solids, toxic compounds, and any different dyes, many of these
dyes are carcinogenic, mutagenic, and toxic to human beings, fish species, and microorganisms.
Hence, their removal from aquatic wastewater becomes environmentally important.
There are several methods available for color removal from waters and wastewaters such as
membrane separation, aerobic and anaerobic degradation using various microorganisms, chemical
oxidation, coagulation and flocculation, and reverse osmosis. Some of these techniques have been
shown to be effective however they have some limitations such as excess amount of chemical usage,
accumulation of concentrated sludge that has serious disposal problems and lack of effective color
reduction. The adsorption technique, which is based on the transfer of pollutants from the solution
to the solid phase, is known as one of the efficient and general wastewater treatment method
The method is superior to other dye removal techniques in terms of initial cost, simplicity of design,
ease of operation, and non–toxicity of the utilized adsorbents compared to other conventional
wastewater treatment methods.
The cost effectiveness, availability and adsorptive properties are the main criteria in selection of an
adsorbent to remove

The Prediction Of The Rate Limiting Step For A Sorption...
The prediction of the rate limiting step for a sorption process is an important factor. The process
consists of four consecutive steps: transport of the solute from the bulk solution through a liquid
film to the exterior surface of the adsorbent (film diffusion), binding of adsorbate molecules to the
active sites of the surface of the sorbent, transport of the solute within the pores of the sorbent
(intra–particle diffusion) and binding of the solute molecules on the active sites distributed within
the sorbent's particles. Generally, the steps involving binding are rapid and can be neglected when
evaluating the rate–determining step of the sorption process.(Kumar &Gaur 2011) The Morris–
Weber model (Weber &Morris 1963) is widely used to identify the mechanism involved and to
distinguish between film or intra–particle diffusion. It is described by Eq. (7): q=kd t1/2 + C (7)
where, kd is the intra–particle diffusion rate constant (mg g–1 min–1/2) and C (mg g–1) is the
intercept of the vertical axis. The intercept reflects the boundary layer effect and the linearity of the
plot of q versus t1/2 denotes the presence of intra–particle diffusion. If C = 0, then intraparticle
diffusion is the rate–controlling step, whereas if C ≠ 0, intra–particle diffusion is not the rate–
controlling step, but film diffusion plays an important role in the metal sorption process. (Al–Degs
et al. 2006). As may be seen in Fig. 4, there is a linear dependence of q on t1/2 at all temperatures

Heavy Metals And Its Effects
1. Introduction
Heavy metals and their salts (Cu, Zn, Hg, Pb, Co, Ni,) are widespread industrial pollutants. In the
waters they come from natural sources (rocks, the surface layers of soil and groundwater), the
wastewater of many industrial enterprises and rain (polluted with smoke emissions). Heavy metals,
as trace elements, are constantly encountered in natural waters and aquatic bodies depending on the
geochemical conditions.
Heavy metals are quite stable and cannot be destroyed. Entering the ponds, they are included in the
cycling of matter and subjected to various transformations. Inorganic compounds are rapidly
solubilized in water and transferred into poorly soluble hydroxides, carbonates, sulfides and
phosphates. Later, these insoluble products settle down and contaminate the bottom sediments.
Under the influence of living organisms (bacteria, fungi and others) mercury, tin, and arsenic
undergo methylation, becoming more toxic alkyl compound. Moreover, metals can be accumulated
in various organisms and incorporated in the food chain and cause poisoning.
This project focuses on the elimination of cobalt (II) metal ions from contaminated waters. Even
though Co (II) appears to be one of the essential elements to human body at low concentrations,
when cobalt is too concentrated; it may damage human body and may cause diseases such as asthma
and pneumonia1. Cobalt pollution may be caused by many alloys (super alloys in gas turbine of
aircraft engines, corrosion resistant

Characterization Of Photo Catalysts : Raman Spectroscopy
Results & Discussions: Characterization of photo–catalysts: Raman Spectroscopy:
Figure (2) shows the Raman spectrum of prepared activated carbon (AC). The sample shows the
characteristic D and G carbon peaks at 1380 cm−1 and 1585 cm−1, respectively. In simple terms,
for carbon materials, the D peak intensity correlates with defects in the carbon lattice and is linked
to the extent of sp3 hybridization while the G peak arises from the graphitic network and extent of
sp2 hybridization. ID/IG = 0 .663, it is smaller than 1, so the structures are considered to show a
higher concentration of sp2 hybridization (i.e. extended graphitic character). Moreover, the ratio is
close to 1 then the material is considered to have a more amorphous structure with a mixture of sp2
and sp3 hybridization. In this case, where ID/IG is close to 1, the presence of a 2D peak, further
associated to interactions between graphene–like planes, suggests a strong graphitic component.
Figure (2): The Raman spectrum of AC. Field Emission Scanning Electron Microscope (FE–SEM):
The activated carbon was scanned by scanning electron microscopy .Figure (3) showed that the
prepared activated carbon had an irregular spherical and porous surface, which indicated high
surface area.
Figure (3): FE–SEM of AC.
Figure (4) showed the FE–SEM images of neat TiO2 (a) and 70TiO2–AC (b, c). Titania in TiO2–
AC composite has distributed in carbon framework along the entire and external surface of the
carbon

Comparing The Langmuir And Bet Isotherms
Figure 3– Comparison of the Langmuir and BET isotherms
Fig. 3 compares Langmuir and BET isotherm shapes: gas adsorption along the BET isotherm
contributes more significantly at early time of production than that of Langmuir isotherm curve. The
reason for this is the slope of the BET isotherm curve at higher pressure is larger than that of the
Langmuir isotherm curve, resulting in more adsorbed gas releasing at early production times. The
amount of released adsorbed gas with BET isotherm curve is larger than that with Langmuir
isotherm curve under the same pressure drop from the initial reservoir pressure to the bottom hole
pressure.
Dubinin–Astakhov equation
To describe adsorption in micro porous material, Dubinin–Astakhov have proposed form of
Dubinin–Rudishkevich equation which has the form: a=W_0 ρ_L exp{–D[Tln(P_s/P)]^n }
Where,
a – concentration (adsorbed mass per unit adsorbent mass)
W_0 – Maximum adsorption capacity (volume of adsorbate/mass of adsorbent) ρ_L – Specific mass
of the liquid adsorbate
D – Coefficient of affinity n – Characteristic parameter of the adsorbent–adsorbate pair
Adsorption Isotherm Models for Multi– Components
Shale reservoir would rarely contain a pure hydrocarbon fluid. Sometimes the fluid type dry gas
may have two or three components accounting for more than 99% of the composition. In some
cases, the liquid fluid may contain more than 40 components. There is a large transition zone
between the dry gas and the liquid areas. In this

Taking a Look at Heavy Metals
Heavy metals are elements that exhibit metallic properties. It mainly includes the transition metals,
basic metals, some metalloids, lanthanides, and actinides. Many different definitions have been
proposed–some based on density, some on atomic number or atomic weight, and some on chemical
properties or toxicity (Duffus, 2002). Example for some heavy metal are iron (Fe), zinc (Zn), copper
(Cu), lead (Pb), mercury (Hg), cadmium (Cd) etc.
Iron is important as a mineral in human body (part of haemoglobin) and also part of many enzymes
and proteins. Deficient amount of iron in human body will cause anaemia while excess amount of
iron may cause iron poisoning or hemochromatosis. Zinc is a metal which known as essential trace
element as very little amount of it is necessary for human health. Zinc is important for cellular
metabolism, catalytic activity of enzyme, immune system, synthesis of protein, wound healing, cell
division and DNA synthesis (Sandstead, 1994; Solomons, 1998; Prasad, 1995). However, excess
amount of zinc may lead to remarkable health problems such as depressed immune system, stomach
cramp, vomiting, nausea and anaemia and skin irritation.
Cadmium (II) ions are known of its toxicity in trace amount may result in poor health effect.
Cadmium can be found easily in contaminated food or water. Workers of metal refining or smelting
factory or cadmium product manufacturing have a high possibility to be exposed to cadmium. Long
term exposure of cadmium lead to

The Design of a Uniform Pore Structure Is Favorable to...
The isotherms of three samples investigated by the nitrogen adsorption/desorption were shown in
Figure 2. The curves of all three samples show hysteresis behavior and belong to type IV
isotherms31. It suggests that our samples exhibit mesoporous structure with pore sizes larger than
5.6 nm (Table 2). The pore diameter of thiol–functionalized SBA–15 calculated by the BJH theory
is smaller than that of SBA–15, which is attributed to the anchoring of thiol moiety to the silanol
group in the interior wall of SBA–1540. The decrease of pore size, while maintaining type IV
isotherm characteristics in thiol–functionalized SBA–15, is one possible reason that thiol moieties
are located along the interior pore channels of SBA–15, not in the internal framework of SBA–15.
The further decrease of pore size in Bi–thiol–functionalized SBA–15 can be explained by the
attachment of bismuth to the thiol group, narrowing the inner pore channel of SBA–15. The BET
surface areas of SBA–15, thiol–functionalized SBA–15, and Bi–thiol–functionalized SBA–15 are
847, 512, and 347 m2/g, respectively. The pore volumes of those are 1.03, 0.85, and 0.62 cm3/g,
respectively (shown in Table 2). The gradual decrease of the surface area and pore volume can also
be understood in the attachment of thiol group to the inner wall of SBA–15 or bismuth to the thiol
group as discussed above. Interestingly, the pore diameter of Bi–SBA–15 is similar to that of SBA–
15, indicating that bismuth is not impregnated to the

Adsorption Modeling Of Breakthrough Curves
Adsorption modeling of breakthrough curves
A successful design of a column adsorption process requires prediction of the concentration–time
profile or breakthrough curve for the effluent. (a,aa14, aa15, aa7, aa2). There are two widely used
approaches to obtain the breakthrough curve of a given adsorption system: direct experimentation or
mathematical modeling. The design of an adsorption column through experimental method provides
a direct determination of the salient parameters based on the breakthrough curve. However, the
extensive experimentation is usually a time–consuming and economically unfeasible. (B6 )
Comparatively, mathematical modeling is simple and provides a method of estimating the column
adsorption capacity without ... Show more content on Helpwriting.net ...
A linear regression was applied to equation 4 and the values of No and ka were computed from the
slope and intercept of the BDST plot between ln(Co/Ct –1) versus t at different adsorption
parameters such as flow rate, bed height and influent adsorbate concentration. These BDST
parameters were used to predict the maximum metal uptake capacity (qcal) under different process
conditions and were compared with the experimental values (qexp) in relation to the estimated
values of ka and No. As shown in Table 1a and b, the values ka decreased with increasing bed depth
and influent metal concentration, but increase with increasing flow rates. Meanwhile, the values of
No declined with the increase in bed height and flow rate. This trend can be explained on the fact
that at increased bed heights more number of active sites is available for sorption to give higher total
metal uptake but reduced per unit removal, whereas at increased flow rate the volume of adsorbate
that entered the column was higher and caused the bed to saturate early. As with increased metal
concentration, the No values were found to be increasing due to higher loading of metal on the
adsorbent achieved in a short period of contact. This discussion shows that the overall kinetics of
adsorption process is governed by external mass transfer. (aa26, aa7,aa14, aa27)
The BDST model is valid for the describing the initial part of breakthrough curve

Water Contamination Research Paper
Water contamination due to increased population and industrial activities is one of the most
challenging issues to the researchers, because it is continuously increasing threats to both human
health and the environment. With the rapid development of industries such as metal plating
facilities, mining operations, fertilizer industries, tanneries, batteries, paper industries and pesticides,
etc.,(1,2) heavy metals wastewaters are directly or indirectly discharged into the environment
increasingly, especially in developing countries. Unlike organic contaminants, heavy metals are not
biodegradable and tend to accumulate in living organisms. Many heavy metal ions are known to be
toxic or carcinogenic and cause high blood pressure, anemia, cancer, renal kidney disease, nervous
system ... Show more content on Helpwriting.net ...
Owing to the standard limits of water, it generates a strong demand to improve the efficiency of
existing methods for removing Pb and Zn from the water. Many techniques have been reported for
the effective removal of hazardous heavy metals from aqueous solutions such as adsorption,
flocculation, coagulation, membrane filtration, electrochemical operations, solvent extraction, bio–
sorption, chemical precipitation, ion–exchange, as well as various other processes (6–7). However,
most of these techniques have several disadvantages such as production of secondary pollution, high
cost, high levels of energy and chemicals needed, and weak treatment operation at low metal
concentrations. (8–9). Adsorption is now recognized as an effective and economic method for heavy
metal wastewater treatment. The adsorption process offers flexibility in design and operation and in
many cases will produce high–quality treated

Characteristics Of The Biochar Derived From Pine Fruit...
Characteristics of the biochar
The characteristics of the biochar derived from pine fruit residue are shown in Table –1. The
adsorptive properties of sorbent are greatly dependent on their particle size and distribution
throughout the mass. Effective size and uniformity coefficient are the two important parameters for
treatment of contaminated water using adsorbent as filtering media in column operation where
control of particle size is critical. The effective size corresponds to the sieve size through which
10% of the material will pass, and the uniformity coefficient is the ratio of the sieve size that will
just pass 60% of the material to the effective size. Generally, the rate of adsorption get enhanced as
the particle size decreases due availability of increased surface area. Therefore, the adsorbent with
smaller effective sizes provide better adsorption capacity due to better the access to the surface area
and faster the rate of adsorption. The typical range of effective size and uniformity coefficient for
activated carbon as adsorbent media practiced satisfactory is D10 = 0.15–0.35 mm and Cu = 2–3
respectively. In our case, Table 1 shows that the biochar prepared have an effective size of 0.055
mm and uniformity coefficient 2.87. The more uniform adsorbent media is expected to provide the
slower head loss buildup and therefore, careful consideration of particle sized distribution is must
for dynamic column design.
The Cd(II) adsorption capacity of biochar depends upon

Pressure Swing Adsorption ( Psa ) : Application Of...
Pressure Swing Adsorption(PSA): Application of Interfacial Phenomenon Adsorption(gas on solid,
different from absorption)
Types of Adsorption: chemical adsorption and physical adsorption
Principle
Surface Energy
Thermodynamics of surface adsorption
Isotherm Models(introduction of Linear, Langmuir, BET and Freundlich models)
Langmuir Adsorption Theorem
Introduction to PSA
Industrial Application of PSA
Industrial data analysis
Current Development in PSA(literature review)
Scope
Adsorption
Adsorption is a surface phenomenon in which the molecules of a gas, liquid or a dissolved solid
adhere to the surface of another phase with which it is in contact. There are two generally used
terms in this phenomenon: ... Show more content on Helpwriting.net ...
The molecular movement is found to be restricted because of these strong intermolecular forces and
typically a monolayer is formed. It takes place at high temperature because the heat of adsorption is
high. It is highly specific and irreversible process.
Physical Adsorption– In physical adsorption, weak Vander waal's intermolecular forces of attraction
is involved between adsorbate and adsorbent. It takes place at low temperature and does not require
any activation energy to overcome the weak vander waal's forces. It is not very specific and
reversible process and therefore is of much use for the separation of fluids. The application of
physical adsorption has major application in the industries like hydrogen and oxygen purification.
Surface Energy
As the name suggests, it refers to the energy at the surface of an interface. Because of this excess
energy, the material tends to accumulate at the interface of the two media. For example, in case of
air and pure water interface water molecules at the interface has higher energy than the water
molecules in the interior of the water phase. The reason of this excess energy is the unbalanced

force component on the airside of the molecule. It requires energy to bring the molecules on the
surface as the at least one of the interior bond must be broken. This excess

Removal Of Copper ( II ) Ions From Aqueous Solution Using...
REMOVAL OF COPPER(II) IONS FROM AQUEOUS SOLUTION USING KAOLINITE AND
METAKAOLINITE
Jean Jacques Anguile1, Kevin Toung Eko1, Guy Merlain Tagne2, Daouda Kouotou2⃰, Joseph Ketcha
Mbadcam2
1–Department of Chemistry, University of Science and Technique of Masuku, Franceville – Gabon
2–Applied Physical and Analytical Chemistry Laboratory, Department of Inorganic Chemistry, P.O
Box 812 Yaoundé, University of Yaoundé I – Cameroon
Abstract
The adsorption potential of two clays namely Kaolinite (KAO) and Metakaolinite (MKB) for the
removal of copper (II) ions from aqueous solution was investigated. The chemical and
morphological characterization of KAO and MKB were carried–out using X–Ray diffraction
(XRD), X–ray Fluorescence Spectroscopy (XFS) and ... Show more content on Helpwriting.net ...
According to the World Health Organization (WHO), the acceptable limit dose of copper (II) ions in
drinking water approved is 2.0 mg/L. Therefore, the removal of copper (II) ions from wastewater is
urgent before their rejection into the environment in order to preserve public health and
environmental disorder. Thus it has been a matter of concern of several researches in recent years.
Copper (II) ions can be removed from wastewater by using different techniques including chemical
coagulation, ion exchange, solvent extraction and adsorption. Among these above cited techniques,
adsorption is the mostly appreciated due to its easier protocol, efficiency and low operation cost. In
matter of fact, several adsorbents such as clays [4–5], wheat shells [6], bagasse fly ash [7], modified
goethite [8] and metakaolin–based geopolymer [9] have been used for this purpose. A particular
attention had been paid to clays which are available, cheaper and possessed interesting chemical and
mechanical properties. Additionally, clay minerals have different adsorption capacities for metal
ions. They have been found to be very effective, economical and versatile [10]. In the scientific
literature, several studies have been reported on kaolinite clay for adsorption of heavy metals from
aqueous solutions [4, 11]. In this present work, a natural kaolinite (KAO) and its thermal treatment
form, metakaolinite (MKB) were

Morphologies Of The As-Formed Zeolite Nannostructures...
3.2. SEM and TEM studies
Morphologies of the as–prepared zeolite nanostructures products (ZF, ZM, ZS, and ZT) have been
examined using both of scanning electron microscopy (SEM) and transmission electron microscopy
(TEM), as shown in Figs. 3 and 4, respectively. The images taken by SEM demonstrated that ZM
and ZT are made up of aggregates of a sphere like structures with an average size of ca.3.54 and
3.07 μm, respectively. In addition, ZF and ZS samples were found to consist of aggregates of a
(sphere and sheet) and (sphere and cubic) like structures with an average size of ca. 10.33 and 8.65
μm, respectively. Moreover, TEM images, exhibits that the samples; ZF, ZM, ZS, and ZT, are
composed of (spherical), (spherical and irregular), ... Show more content on Helpwriting.net ...
(13)). log (Qe–Qt) = log Qe–K1t/2.303 (8) t/Qt = (1/K2Qe2) + (1/Qe) t (9)
Qt = Kint t 0.5 +C (10) ln Ct = ln Co–Kextt (11) ln (1–F) = – Kextt (12) log R = log [Ko m/ 2.303V]
+ α log t (13) where, Qe (mg/g) is the amount of the adsorbed dye at equilibrium, Qt (mg/g) is the
amount of the adsorbed dye at time t (min), k1 (1/min) is the pseudo– first–order rate constant, k2
(g/mg.min) is the pseudo–second–order rate constant, C (mg/g) is the thickness of boundary layer,
kint (mg/(g.min0.5)) is internal diffusion constant, Kext (1/min) is external diffusion constant, Ct
(mg/L) is the concentration of dye at time t, F is fraction attainment of equilibrium or extent of
conversion and it was calculated using Eq. (14), α (mg/g.min) <1) and Ko (g/mg.min) are the
Bangham constants. In addition, R can be calculated using Eq. (15)
F = Qt/Qe (14)
R = log [Co/ (Co–Qtm)] (15)
Figure 7 (A–F) represents all of the above six kinetic models, respectively. Moreover, all of the
constants and correlation coefficients for the above six kinetic models were calculated in Table 3.
The data exhibited that the adsorption process of malachite green dye follows the pseudo–second–
order model more than pseudo–first–order, because the correlation coefficients of the first model is
greater than

Inorganic Chemicals Cause Water Pollution
Inorganic chemicals is one of most important causes to water pollutants. These inorganic pollutants
naturally found in environment but due to human develepment activities, these pollutant amount has
been increasing rapidly and released into water bodies. The most common inorganic pollutants from
water are ammonium, phosphorus, arsenic, cadmiun, zinc, lead etc. It is highly toxic to human and
environment (Choi et al., 2011). The inorganic pollutant such as ammonia and phosphorus promote
eutrophication, which excessive amounts of these inorganic pollutant releasing into the water can
accelerate this phenomena in a few years (Donald M et al., 2002). The overgrowth of plants and
subsequent death have been created green layer on the surface of water bodies. These layer can be
blocked the penetration of light and oxidation process into the water bodies. Thus, depletion of
dissolved oxygen can be occurred in the water and affected aquatic life. The death and decay of
aquatic life contribute unpleasant smells and increasing the turbidity of water bodies (Conley et al.,
2009). In additional, the heavy metal such as arsenic can causes skin, lung, bladder, and kidney
cancer as well as pigmentation changes, skin thickening (hyperkeratosis) neurological disorders,
muscular weakness, loss of appetite, and nausea (Mohan and Pittman, 2007). The long term
exposure to cadmium causes various types of acute and chronic disorders like pulmonary odema,
erythrocyte destruction, skeletal

Adsorption : Dynamic And Dynamic Adsorption Process Design...
Adsorption Colum dynamic studies
In general, the most of the adsorption processes are classified into static and dynamic adsorption
based on their mode of operation. With dynamic adsorption the adsorbate solution is in continuous
contact with the adsorbent packed in a fixed bed column. Therefore, the understanding of the
column dynamics behavior is essential to predict the performance of adsorptive separations in the
column for process design and optimization of operating conditions. (M1,M4, I8, P3) The
performance of the packed bed column is evaluated through the concept of breakthrough curve
(M3,I7, P2), which is indicative of the transient behavior of concentration profile as function of time
for any defined changes in column parameters ... Show more content on Helpwriting.net ...
The BDST curves obtained by plotting ln(Co/Ct –1) against t were used to calculate the values of
adsorption capacity, No and the rate constant, ka from the slope and intercept of the linear plots.
Table 3 presents the estimated values of the characteristic parameters, No and ka along with the
correlation regression coefficient (R2) of the respective BDST plots. The decrease in values of ka
were observed with increasing bed height and influent Cd(II) concentration, while increased with
increasing flow rates. The values of rate constant, ka greatly influences the shape of the
breakthrough curve in a packed bed column study.(Y4) With higher ka values the breakthrough can
be avoided using lower bed height, whereas as the ka values decreases the progressively longer bed
heights are required to eliminate the breakthrough. (A1) Further, the No values were increased with
increasing bed height and influent Cd(II) concentration. This behavior can be attributed to the
increased contact time of Cd(II) ions with the biochar as the bed height increased (A3) while with
increasing influent concentration provided the higher loading of Cd(II) ions to saturate the biochar
in a short period of contact (T1). As in case with increased flow rate, the No values were decreased
which is indicative of more saturation of adsorbent sites. (Y1) These findings suggest that the
overall adsorption

Natural Gas Dehydration Based On Agricultural By Products
This research project emphasizes on natural gas dehydration based on agricultural by–products
known as biosorbents in a pressure swing adsorption (PSA) process, which is a widespread
industrial separation system. The commercial widely used adsorbents such as zeolites, silica gel, and
molecular sieves are costly due to high regeneration temperature and operational difficulties
regarding maintaining a cyclic process. Moreover, even though these adsorbents are being used in
industries, still a considerable amount of other species are being adsorbed along with the
preferentially species, which lead to lower selectivity. Hence, there has been a constant demand for
cost–effective adsorbent with high selectivity and equilibrium capacity.
The ... Show more content on Helpwriting.net ...
Outlet Tdew around −10 ◦C is usually reached. Adsorption dehydration can obtain very low outlet
water concentration of Tdew<−50 ◦C, and contaminated gases are not a problem. Adsorption,
however, requires high capital investment and has high space requirements as indicated by industrial
experts that the capital cost for an adsorption line is 2−3 times higher than that for an absorption one
[8 comparison method]. Due to sophisticated cooling systems and operational problems dealt with
methane hydrates, condensation methods is not favorable from the standpoint of energy
consumption.
Each of the methods presented has its advantages and disadvantages. Recent published works
revealed that potential biomaterials could be employed for water adsorption efficiently [ethanol and
coconut references]. [potential bioadsorbents that can be used for water adsorption are flax shive,
oat hulls, and canola meal. According to Statistics Canada, ///// tons of flax shive was produced in
Western Canada in 2013 with a commercial price of $ ///, which is much cheaper compared to those
of AC, CMC (3–120 $/ Kg), and silica gel. Canola meal, however, is one of the byproducts of
canola industries including oil extraction and biodiesel production. [Canola meal is composed of
36% crude protein, 12% moisture, 20% neutral detergent fiber consisting of cellulose, hemicellulose
and lignin, 5% starch, 10% free sugar and non–starch polysaccharides, 4% crude fat, and 6% ash
(Canola council of

Using Porous Organometallic Compounds For Various Material...
Introduction
In the past century extensive research has been conducted on porous organometallic compounds for
use in various material applications. Although numerous compounds containing Lewis bases, such
as nitriles and bipyridines and have been reported to be successful at the sorption of small
molecules, the desorption of the guest often leads to structural collapse of the host. 1,2 Metal–
organic frameworks (MOFs) have shown to be a valuable class of newer materials that can support
permanent porosity upon the evacuation of the framework. Unlike zeolites, which are fully
inorganic, the flexibility in the choice of the organic linker comprising the backbone of the MOF
structure makes the size of the poragen formed tunable for a wider ... Show more content on
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One of the original and still most active fields of research in metal–organic frameworks is in gas
separation. While the ability of both rigid and flexible MOFs to adsorb is based on such factors as
geometry of the gas as well as sorbate–sorbent interactions, flexible MOFs are also dependent on
structural rearrangements and the ability of the pore to change with thermodynamic conditions.
Currently, most MOF investigations into gas separation are conducted by measuring the sorption
and desorption of specific gases and relating isothermic data. MOFs are being looked to as next
generation gaseous adsorbent materials in both industrial and environmental applications.9 One
particular gas that is of growing environmental concern is CO2. As a byproduct of human–created
combustion activities, particularly in developed nations, the need to capture and sequester CO2 is
becoming ever more apparent. In order to adsorb CO2, a metal–organic framework must be
functionalized for high selectivity towards the gas as well as possess the necessary enthalpy of
adsorption. MOFs with open cation sites such as MOF–74 derivatives, as well as those containing
amine functional groups are especially useful.10 The

The Nottingham Pulse Rig Towards Determining The Mechanism...
This Chapter discusses the progress made using the Nottingham Pulse Rig towards determining the
mechanism of the Fischer Tropsch reaction. A summary of the three main mechanisms proposed in
the literature was outlined in Chapter 1 but is still the subject of much debate.1–6 Generally the
carbide mechanism is accepted for Fe catalysts,7 but the mechanism over Co catalysts is less clear.1
Ge and Neurock,8 as well as Ojeda et al.,4 have suggested that the carbide mechanism is the
pathway for FT synthesis on Co catalysts. However, they disagree over the route to CO dissociation;
direct dissociation of the carbonyl bond has been proposed by Ge and Neurock, whilst Ojeda et al.
have concluded that carbonyl dissociation proceeds via an H assisted ... Show more content on
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3.1.1 On the Mechanism and Active Site of the FT Process Over Co Catalysts Several studies have
investigated the effect of syngas on the structure of metallic Co catalysts.9–12 For instance, Karaca
et al. investigated the effect of syngas on a CoPt/Al2O3 catalyst using X–Ray Diffraction (XRD).9
After reducing the catalyst in H2 at 623 K, XRD peaks were observed for face centred cubic (fcc)
and hexagonal close packed (hcp) structures of metallic Co. After exposure to 20 bar of syngas at
493 K, the fcc XRD peaks became narrower over 5 hrs, which was suggested to be due to an
increase in the particle size due to sintering of the Co metal phase. Over the subsequent 5 hrs this
peak decreased in intensity and a new peak assigned to a carbide phase grew in. Therefore, the
authors concluded that deactivation of the catalyst was due initially to sintering and then, over
longer periods of time, to carbidisation. Wilson and de Groot have investigated the surface
reorganisation of a model Co catalyst upon exposure to 4 bar of a H2/CO mixture (2:1 ratio) at 523
K.10–11 The surface was examined ex–situ in an Ultra High Vacuum (UHV) chamber before and
after exposure to syngas using a Scanning Tunnelling Microscope (STM). Before exposure to CO
the surface consisted of flat terraces, with a Co(0001) structure. The terrace surfaces were separated
by cliff edges ranging in size from single atom high steps

Course Taking And Apparatus Set Up
Course taking and apparatus set up will be the first steps in this project. For safety measures, the
apparatus needs to be reinstalled under the fume hood. Basic pretreatment processes will be carried
out in order to prepare the biosorbents for adsorption. Aiming to check the reliability of the system
and find possible pitfalls, some preliminary tests will be run, and the results will be analyzed. Once
the reliability of the apparatus, repeatability of the process, and standard operating procedure are
determined, the next phase of the project will be commenced.
5.2 Phase 2
In this phase, the experiments will be focused on single component and binary systems. Firstly, pure
methane will be fed into the column and the adsorption process will be investigated. Afterwards, the
same experiments at similar conditions will be carried out using pure water vapor. Based on the
result of these experiments, a new set of experiments will be designed and carried out for binary
systems (Methane and water vapor). Equilibrium and kinetics will be studied. Dynamic studies will
be accomplished. Generally, the performance of Flax Shive and Oat Hulls in PSA process will be
determined.
5.3 Phase 3
To further investigate the adsorption process, various isotherms will be fitted on the experimental
data. Equilibrium capacity, uptake of species, diffusion constants, and selectivity will be calculated.
Based on these results, the nature of the adsorption process will be determined. Afterwards, a set

Effects Of Geopolymer Adsorbents
reorganization determine the microstructure and pore distribution of the material, which are critical
in determining many physical properties (Duxson et al., 2005; Duxson et al., 2007). Geopolymers
derived from different combinations of raw materials can easily be synthesized containing
multivalent cations (Alonso and Palomo, 2001; Granizo et al., 2002; Lee and Van Deventer, 2002;
Yip and Van Deventer, 2003). Therefore during the course of alkali–mediated reaction, Al (IV) and
Si (IV) are converted to tetrahedral sites with an associated alkali cation to maintain electro
neutrality (Davidovits, 1991). The speciation of aluminum in alkaline solutions is restricted to Al
(OH) 4– (aq) in all but the most concentrated aluminate solutions, ... Show more content on
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2.9 Compositional and microstructural analyses of geopolymers and source materials
The geopolymers like other molecular sieves are characterized using FTIR, SEM, EDS, XRD
among other methods. Characterization using FT–IR spectroscopy is for determination of molecular
vibration of the geopolymers, X–ray diffractometer (XRD) for crystal structure determination, X–
ray fluorescence (XRF) or EDS to qualitatively and quantitatively identify the chemical composition
of principal components (López et al., 2014).
2.10 Adsorption isotherms
Adsorption isotherm is the relationship between amount of sorbate adsorbed by an adsorbent (solid)
and its equilibrium concentration at constant temperature (Theodore and Ricci, 2010). An
equilibrium is arrived at where a number of molecules arriving on the surface of an adsorbent equals
the number of molecules that are leaving (Thajeel, 2013). Equilibrium data is analyzed using
commonly known adsorption systems (Rahimi and Vadi, 2014). The earliest and simplest known
relationships describing the adsorption process are the Freundlich and the Langmuir isotherms
(Jalali et al., 2002). It is a versatile isotherm expression that can simulate both Langmuir and
Freundlich behaviors ( Sips, 1948; Nah et al., 1977). The Langmuir Freundlich isotherm can
describe both the Langmuir–type and Freundlich–type adsorption behavior and has been used for
modeling pH–dependent sorption effects of adsorption

Electrochemical And Quantum Chemical Studies Of The...
Electrochemical and quantum chemical studies of the corrosion and hydrogen evolution reaction of
mild steel in acid medium
Rabab M. El–Sherif a,*, K. M. Zohdy b Sowmya Ramkumar c
a Cairo University, Faculty of Science, Department of chemistry, Giza, 12613, Egypt b Higher
Technological Institute, 10th of Ramadan City, Egypt c Department of chemistry, PSGR
Krishnammal College for Women, Peelamedu, Coimbatore, India
Abstract
Electrochemical behavior and hydrogen evolution reaction of mild steel in sulfuric acid solutions,
containing different concentrations of gamma–Aminobutyric acid (GABA) as a green inhibitor have
been investigated. The electrochemical techniques included Tafel polarization and electrochemical
impedance spectroscopy (EIS). The rate of both the corrosion reaction and the hydrogen evolution
affected significantly by changing GABA concentrations. Polarization results showed that GABA is
a mixed type inhibitor with good inhibition efficiency. Increasing the temperature led to an increase
in the hydrogen evolution rate and a decrease in the total surface resistance value (RT) or the
relative film thickness (1/CT) of the steel. Quantum calculation including EHOMO, ELUMO, the
energy gap (?E) and the fraction of transferred electrons (?N) demonstrated the inhibition ability of
GABA. The results were confirmed by surface examination using scanning electron microscopy.
Adsorption of GABA on the steel surface fitted the Langmuir isotherm. Thermodynamic parameters

Data Analysis Of DNA By The Standard Crystallographic Method
The structure of 2 was determined by the standard crystallographic method, using a colorless plate
crystal (0.028 × 0.034 × 0.046 mm3) of 2 for single crystal data analysis. All the data were collected
using a Bruker SMART BREEZE diffractometer equipped with a 1K CCD area detector using
graphite monochromated Mo Kα radiation at 200 K. A hemisphere of data was collected using a
narrow–frame method with the scan widths of 0.30° in omega and an exposure time of 5 s/frame.
The first 50 frames were remeasured at the end of the data collection to monitor the instrument and
crystal stability. The maximum correction applied to the intensities was 2σ(I). All the calculations
were performed using the WinGX–98 crystallographic software package ... Show more content on
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The specific surface area was estimated by the Langmuir surface area based the CO2 adsorption at
195 K.
2.6 Second–order nonlinear optical measurements
Powder second–harmonic generating (SHG) measurements of polycrystalline material 2 were
performed using a modified Kurtz–NLO system using 1064 nm radiation [33]. A DAWA Q–
switched Nd:YAG laser, operating at 20 Hz, was used for the measurements. Because the SHG
efficiency has been shown to depend strongly on the particle size, polycrystalline samples were
ground and sieved (Newark Wire Cloth Co.) into distinct particle size ranges (20–45, 45–63, 63–75,
75–90, 90–125, 125–150, 150–200, 200–250, >250 μm). To make relevant comparisons with the
known SHG materials, crystalline α–SiO2 and LiNbO3 were also ground and sieved into the same
particle size ranges. Powders with the particle size in the range 45–63 µm were used for comparing
the SHG intensities. All the powder samples with different particle sizes were placed in separate
capillary tubes. No index matching fluid was used in any of the experiments. The SHG light, i.e.,
532 nm green light, was collected in reflection and detected using a photomultiplier tube
(Hamamatsu). To detect only the SHG light, a 532 nm narrow–pass interference filter was attached
to the tube. A digital oscilloscope (Tektronix TDS1032) was used to view the SHG signal. A detailed
description of the equipment and the methodology used has been published [34].
3. Results and

The Concept Of Absorption Isotherms
2.4. Adsorption isotherms, kinetics and thermodynamic studies
2.4.1. Adsorption isotherms
Adsorption isotherms describe the equilibrium between the adsorbents and adsorbate to optimize the
use of adsorbents and introduce a design and operation of adsorption systems by the correlation of
experimental data through the theoretical equations. Isotherm studies were performed by mixing the
optimum dose of both adsorbents with Pb2+ solution at different initial concentration (25–250 mg/l)
and shaking for the optimum time at room temperature. The data was fitted into the following
isotherms: Langmuir, Freundlich, Temkin and Dubinin–Raduskevich.
2.4.1.1 Langmuir isotherm.
Langmuir model is the simplest theoretical model for monolayer adsorption onto a surface with
finite number of identical sites [28]. The general Langmuir equation is as follows: ... Show more
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qmax: maximum monolayer coverage capacity (mg/g) and b: Langmuir isotherm constant

The Use Of Pvp As A Dye Solvent
3.1 Material
Polysulfone (INFO) supplied by (COMPANY) is used as a base polymer. N–dimethylformamide
(DMF) as a solvent in casting solution, 2–propanol as a dye solvent, polyvinylpyrrolidone (INFO)
and n–hexane are obtained from (COMPANY). ZIF–8 nanoparticles as a modification agent are
obtained from (COMPANY). Dye (INFO) is obtained from (COMPANY).
3.2 Membrane Preparation
The PSU/DMF casting solution was prepared by dissolving 18 wt% polysulfone and 1.5 wt% PVP
in DMF at room temperature in magnetic stirrer for 24 h to ensure complete dissolution of the
polymer. The role of PVP was as a pore former (Rahimpour et al., 2012). Then, the solution was set
aside for 12 h to remove air bubbles. The lid of the container was kept closed ... Show more content
on Helpwriting.net ...
This solution was then warmed to room temperature and then mixed with the PSU pre–polymer
solution. The mixed solution was further sonicated for 10 min to minimize nanoparticle aggregation
and sedimentation. The resulting homogeneous solution was stirred and cross–linked for another 2 h
to give enough viscosity for membrane casting. Finally the solution was casted rapidly onto a
spongy ultrafiltration support with a doctor blade and was dried overnight at room temperature. The
membrane was further annealed at 80C for 4 h (Fang et al., 2014).
The ZIF–8 loading is defined as mass proportion of ZIF–8 in PSU which is given by
While the volume fraction of ZIF–8 in mixed matrix membrane is defined as
3.4 Membrane characterization
3.4.1 Surface morphology
The surface morphology and cross–section of NF membranes before and after experiment were
studied using a scanning electron microscope (SEM) (MODEL). The membrane was cut into 1 cm x
1 cm size and subjected to imaging at a defined magnification of 10,000X for top morphology. The
SEM analysis was conducted at an accelerating voltage of 25 kV to observe the membrane 's surface
morphologies and cross–section. Before that, the NF membranes were dried and then coated with
gold using a (MODEL) sputter coater.

3.4.2 Functional group
To demonstrate the presence of different functional groups on membrane surface, before and after
experiment, Fourier transform infrared (FTIR) (MODEL)

Volatile Aromatic Organic Compounds
1. Introduction The release of volatile aromatic organic compounds into the environment is a serious
problem as they distribute between the different phases in natural systems. Sediments can be
considered as a sink for volatile aromatic organic compounds because of their hydrophobic nature
and the resulting affinity to the sediment 's organic matter. Organic matter consists of soft carbon,
where portioning is the main sorption process and hard carbon, where pore filling mechanisms
dominate (Zhao et al., 2002; Chai et al., 2006). Consequently, sorption/desorption processes are the
most important factors that determine the fate of volatile aromatic organic compounds in the
environment. The extensive production and release of aromatic organic compounds has led to a
widespread contamination of soils and sediments with these pollutants throughout the world,
threatening drinking water resources, especially petroleum hydrocarbons as constituents of gasoline
such as Benzene, 1,2 dichlorobenzene, Toluene and m–xylene. It was proposed that sorption of the
sorbate molecules may cause deformation of flexible sorbent solids, such as natural organic matter
and organo–clays resulting in an entrapment of sorbed molecules during desorption (Weber et al.,
2002; Lu and Pignatello, 2004). Several researchers have tried to associate the maximum sorption
capacities of organic compounds with the sorbed amounts in the slow and very slow desorbing
domains (Van Heuvel et al., 2005; Van Heuvel and

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