Microporosity and Surface Functionality of Activated Carbon Essay Sample

Abstraction

Activated Cs have been prepared from jute stick by both chemical and physical activation methods utilizing ZnCl2 and steam. severally. The activated Cs were characterized by measuring surface country. iodine figure. pore size distribution. surface functional groups and surface textural belongingss. Based on the analysis. the activated C prepared by chemical activation method. ( ACC ) featured micropore construction. while the activated C prepared by physical activation. ( ACS ) mostly featured macropore construction. The BET surface country of ACC and ACS was 2300 m2/g and 730 m2/g. severally. The FT-IR spectra revealed that a important figure of organic functional groups are indiscriminately distributed on the big surface country of ACC. meanwhile it was really limited for ACS. The microporosity along with surface functional groups provided a alone belongings to ACC to adsorb methylene bluish dye. which is a representative basic dye for fabric industries. in a big extent compared to ACS. The surface assimilation of dye utilizing both ACC and ACS was besides affected by the surface assimilation parametric quantities such as surface assimilation clip. temperature and pH. Relatively higher temperature and pH facilitated dye surface assimilation significantly. particularly for ACC.

Keywords: Activated C. Jute stick. Chemical activation. Methylene blue. Adsorption

1. Introduction
Activated Cs ( AC ) possess high surface country with porous constructions and are widely known as efficient adsorbents for both gas and liquid stage surface assimilations. The increasing environmental concern significantly increased the pertinence of AC for industrial pollutants separation. The wastewaters from industries. such as fabric. leather. paper. ink and cosmetics every bit good as from the industries that produce dyes are badly contaminated with dyes. pigments. wetting agents and many other toxic chemicals. These contaminated wastewaters finally go to the surface H2O reservoir. The dye contaminated H2O even in a really low concentration is seeable and aesthetically unacceptable. As most dyes are toxic and chiefly pollute surface H2O. the H2O biology is the primary victim of dye taint. and long exposure of dyes in H2O frequently causes nutrient concatenation taint. ensuing in inauspicious wellness consequence. Hence. it is compulsory to cut down contaminant concentration in outflowing holla acceptable scope before being released into the environment by using proper intervention procedure. Due to the technological promotion. legion procedures have been attempted to take dyes and other contaminations from wastewater in the last few decennaries.

The most often used procedures are adsorption [ 1-4 ] . oxidation–ozonation [ 5 ] . photocatalysis [ 6 ] . biological intervention [ 7 ] . coagulation–flocculation [ 8 ] and membrane separation [ 9 ] . Among the procedures. the surface assimilation is the most various and economic due to many advantages. Although the biological intervention for organic compounds removal from H2O is some extent effectual. the remotion of organic furnace lining contaminations has proven to be really uneffective. Even the contaminations are non reactive. the adsorbent can take contaminations satisfactorily [ 10-12 ] . A figure of adsorbents are used for dye remotion including agricultural wastes. wood stuffs. industrial wastes and man-made stuffs [ 1 ] . Activated Cs. which can be produced from agricultural wastes. are known as really effectual adsorbents for dye surface assimilation [ 13 ] . The alone surface assimilation belongings is developed on the AC surface due to the development of microporosity. big surface country ( normally 500 -3000 m2/g and variable features of surface chemical science [ 14. 15 ] . These belongingss of AC can be regulated by modulating the readying methods and their conditions every bit good as by choosing the precursor stuffs. A really selective AC can be prepared with a precise readying method from a suited precursor for a specific dye separation.

The surface assimilation of dye molecules onto the AC surface depends on the pore size distribution. surface functionality every bit good as the size and form selectivity of the molecules to be adsorbed. For an optimal surface assimilation. the molecular size of the adsorbates demands to be rather fitted to the pore size of the AC. The pore size of the AC is classified as micropore ( & lt ; 2 nanometer ) . mesopore ( 2-5 nanometer ) and macropore ( & gt ; 5 nanometer ) [ 16 ] . Both in the gas stage and liquid stage separations. the micro- and mesopores play major function [ 17. 18 ] . The macropore construction leads to the smaller surface country of AC every bit good as the multilayer surface assimilation is limited in macropore. which attributes to the lower surface assimilation capacity. Therefore. the pore size and construction of AC need to be optimized for a specific separation. The activated C from difficult wood is particularly used for gas separation and that is from soft wood is used for solution stage separation. The chemical activation utilizing H3PO4. ZnCl2. KOH and K2CO3 is known to bring forth micropore and mesopore construction in AC [ 19 ] .

However. the physical activation utilizing steam frequently produces activated C with macropore construction [ 20 ] . Activated Cs from the soft cellulosic precursors. particularly from agricultural residues are widely used for dye molecule separation from solution [ 1 ] . Phenol and many inorganic contaminations such as arsenic and quicksilver are besides potentially environmental jeopardies and are separated utilizing AC prepared from agricultural residues [ 21 ] . The presence of functional groups on AC surface provides mutual opposition. which in bends influence surface assimilation belongingss. The IR spectroscopic surveies represented that during heat intervention at high temperature to bring forth AC. most of the reactive functional groups on the surface of biomass are released as H2O. CO2 and many other little molecules. go forthing behind quinolic. etheric. phenolic and ketonic functional groups [ 22 ] .

These O incorporating surface functional groups provide acidic every bit good as basic belongingss depending on the ring structures [ 23 ] . The extent of pealing condensation during activation has besides a function to play to organize a broad basal surface of AC. which facilitates the adjustment of dye molecules in surface assimilation. Some surveies showed that during steam activation of char at 700-900oC the structural characteristics of C drastically changed due to the condensation of smaller ring systems ( 3-5 fused rings ) to larger pealing systems ( ?6 fused rings ) [ 24 ] . The surveies besides showed that the responsiveness of staying char with O drastically decreased with increasing the contact clip of steam with char. However. since the chemical activated C is frequently produced at around 500oC. much lower than steam activation temperature. a important figure of functional groups are assumed to be retained on the surface. The readying. word picture and use of activated Cs for dye separation were the aims of this survey. Jute stick. which is copiously available agricultural residues in most of the Asiatic states. was used as a precursor for activated C readying by chemical and physical activation methods. Both of the activated Cs were characterized and utilized for methylene bluish dye separation.

2. Experimental

2. 1. Preparation of feedstock
Jute stick of normally cultivated assortments. Corchorus capsularis. in Asiatic states was collected. washed with distilled H2O and dried at 105oC for 12 h. The atom size of 1-2 millimeter was prepared by crunching and screening of original jute stick. The wet content of the dried jute stick was found to be about 4 wt % . The physical belongingss. proximate and ultimate analyses of jute sticks have been published elsewhere [ 25 ] . The proximate analysis exhibited 76–78 wt % volatile fraction. 21–23 wt % fixed C and 0. 62 wt % ash output. The ultimate analysis resulted in 49. 79 wt % C. 6. 02 wt % H. 41. 37 wt % O. 0. 19 wt % N. 0. 05 wt % Cl and 0. 05 wt % S. Zinc chloride ( 99. 0 % . BDH Chemical Co. ) was used as an energizing agent. Iodine ( 99. 5 % ) . Sodium thiosulphate ( 99 % ) . Potassium iodide ( 99. 5 % ) . Hydrochloric acid ( 35 % ) . Potassium bichromate ( 99. 9 % ) were purchased from Loba Chemicals Co. . India. Commercial activated C ( Laboratory Reagent. Thomas Baker Chemicals Ltd. ) and Methylene Blue ( 99. 9 % . Aldrich ) were used in this probe.

2. 2 Preparation of activated C
The readying of activated C from jute stick by chemical activation utilizing ZnCl2 involved three stairss: ( 1 ) socking of reagent solution by jute stick atoms. ( 2 ) low temperature ( 200 oC ) carbonisation to bring forth char and ( 3 ) high temperature ( 500 oC ) activation of char. About 50 g of dried jute sticks was assorted with ZnCl2 solution and maintain for approximately 15 H at room temperature. The solution was wholly socked by the solid mass. The ZnCl2 to jute stick ratio was adjusted to 1:1. The moisture solid was so transferred into a unstained steel reactor. The reactor constellation. published elsewhere [ 26 ] . was 25 centimeters long with 5 centimeters internal diameter. The inside temperature of the reactor was controlled by a temperature accountant through a thermocouple inserted into the reactor. Before heating the reactor. N gas was purged for approximately 10 min at the rate of 200 mL/min to replace the air inside the reactor. Then the reactor was heated to 200 oC at the heating rate of 5 oC/min and was held for at least 15 min at this temperature. while the N gas was continued to flux. During this operation. the jute stick atoms were carbonized and converted to sticky and black semi solid mass.

The temperature was further increased to activation temperature at the heating rate of 5 oC/min. The carbonized merchandise was activated at around 500 oC. The concluding merchandise was washed with deionised H2O. For rinsing. the solid merchandise was assorted with deionised H2O in a beaker and stirred for 20 min at 60 oC and so the solid mass was separated by agencies of a vacuity filter. The procedure was repeated in order to take ZnCl2 about wholly. To observe the presence of ZnCl2 in the exhausted H2O. 2/3 milliliter of it was taken in a trial tubing and a few beads of AgNO3 solution was added into it. Appearing of a white precipitate indicated the presence of ZnCl2. Therefore. the lavation of the merchandise was repeated until no being of white precipitate observed in the trial tubing. Finally. the AC sample was dried at 105oC for 24 H and stored in a desiccator. The activated C prepared by chemical activation method was denoted as ACC. From the entire weight loss due to the activation of jute stick. the output and activation burn-off were calculated utilizing the undermentioned Equations 1 and 2. severally: Y ( % ) = [ movie ] …………………… . ( 1 )

Yttrium ( ( % ) = [ movie ] … . …………… ( 2 )
where Y and Y ( are yield of activated C and activation burn-off. severally. M ( g ) is mass of activated C obtained and Mo is initial mass of jute sticks in dry footing. The activated C was besides prepared by physical activation method utilizing steam under optimal conditions as investigated in our old work [ 27 ] . In this method. 50 g of jute stick was placed in a chromium steel steel reactor and was heated to 700 oC at the heating rate of 5 oC/min under the N gas flow of 200 mL/min. When the temperature attained to 700 oC. the steam was started to flux through the char bed into the reactor. The steam flow rate was 75 mg/min. For steam coevals. the H2O was supplied by a Peristaltic Pump into the upper hot zone of the reactor. where the H2O was all of a sudden vaporized and the vapor was assorted up with N gas and went through the char bed. When the steam contacted the char. a gasification reaction took topographic point. let go ofing CO and CO2 and go forthing behind the porous C construction. At the terminal of the procedure the activated C was allowed to chill to room temperature. Finally. the activated C was washed with 0. 1 M HCl to take ash and so washed with deionised H2O to take residuary acid. This activated C was denoted as ACS.

2. 3Characterization

The ACC and ACS were characterized in footings of specific surface country. iodine figure. pore size distribution. surface chemical science. and surface textural belongingss. The surface country and pore size distribution were measured by nitrogen surface assimilation method at ?196 oC utilizing a Surface Area Analyzer ( Model: AUTOSORB – 1 ) in order to clarify the microporosity of activated Cs. For nitrogen surface assimilation surveies. the samples were degassed for 24 H at 50 oC to guarantee complete emptying of micropore. The iodine figure was determined based on the Standard Test Method ( ASTM D4607-94 ) . In order to cognize the surface functional groups. the FT-IR spectra of ACC and ACS were recorded between 4000 and 450 cm-1 utilizing a Perkin-Elmer Spectrum GX FT-IR/Raman spectrometer. Fifty scans were recorded at 4 cm-1 spectral declaration. For this survey. the samples were land and diluted to 0. 5 wt % with spectroscopic class KBr. A thin movie was prepared from the ensuing mixture utilizing Perkin-Elmer manual hydraulic imperativeness. A scanning negatron microscope ( SEM ) ( Model JEOL 840 ) equipped with an energy diffusing X-ray microanalysis was used to find the surface textural features of the samples.

2. 4Dye surface assimilation

Activated Cs. ACC and ACS were used for Methylene Blue dye surface assimilation from H2O. In each experiment 0. 1 g of adsorbent was added into 50 milliliters dye solution in a conelike flask. The flask was sealed with paraffin tape to avoid the vaporization and shaken for a coveted length of clip in a thermostatic orbital shaker at 25 oC. After surface assimilation. the solution was filtered out and the concentration of the residuary dye solution was measured utilizing a Visible Spectrophotometer ( ANA – 75 ) at ( max 626 nanometer. The same process was followed for a clean experiment to avoid any experimental mistake. The equilibrium surface assimilation of dye from different concentrations on ACC was measured to measure the Langmuir surface assimilation isotherm theoretical account. The sum of dye adsorbed. x/m was calculated and fitted to the undermentioned Langmuir Equation ( 3 ) :

[ movie ] ……………… ( 3 )

where Ce is the dye concentration in the solution under equilibrium status ( mg/L ) . x/m is the entire measure of dye adsorbed per unit weight of ACC at equilibrium ( mg/g ) . xm is the maximal monolayer surface assimilation capacity ( mg/g ) . and KL is the Langmuir surface assimilation invariable ( L/mg ) and it is related to the free energy of surface assimilation. The consecutive line was fitted to the points by the least square method. where the incline of the arrested development line is 1/xm and the intercept is 1/KL. 1/ xm

3. Consequences and treatment

3. 1. Output. surface country and iodine figure of activated C The activation burn-off. output. specific surface country and iodine figure of ACC and ACS are tabulated in Table 1. The mass decreased during activation is called activation burn-off. The output was accounted by deducting the activation burn-off from the entire mass of biomass and it was 46. 0 % for ACC. while it is 12. 0 % for ACS. In the chemical activation. the bond cleavage initiated by the reaction of triping agent. ZnCl2 in jute stick resulted in the development of little molecules such as H2O. CH3OH. HCHO. CH3COOH. CO2 etc. These little gaseous merchandises released from the C matrix. go forthing behind the skeletal construction of Cs. This reaction took topographic point on the outer surface every bit good as in the micro-pore surface. so as to increase the figure of pores every bit good as the size of pores. The entire sum of devolatilized merchandises could be accounted to around 50. 0 % under optimal status. which after rinsing and drying resulted in 46. 0 % .

The reactions occurred in the chemical activation procedure were influenced by activation temperature. and therefore increasingly increased the activation burn-off. resulted in decreased output of ACC as we have observed in our old work [ 22 ] . However. the BET surface country. which was created by the activation burn-off. increased merely up to 500 oC. Further addition of temperature from 500 to 600 oC resulted in decreased surface country. This was due to the loss of some pore walls due to inordinate C burn-off. For physical activation. the major portion ( around 70 % ) of the entire burn-off occurred at the pyrolysis temperature at unit of ammunition 500 oC. while another 18 % mass decrease occurred at activation temperature ( 700 oC ) . This immense burn-off resulted in really low output ( 12 % ) of ACS every bit good as it was an declarative of less pore denseness but bigger pore size. and therefore the surface country was besides really low ( 730 m2/g ) [ 22 ] . A farther note revealed that the iodine figure was much higher for ACC ( 2105 mg/g ) than that of ACS ( 815 mg/g ) . It reflected to the prevailing micropore construction of ACC. while it was macropore construction of ACS and it could be supported by the consistent reported consequences [ 28 ] .

3. 2. Concentrate size distribution

The pore size distribution has been analyzed by different methodes like Barrett. Joyner & A ; Halenda ( BJH ) . Dubinin-Astakhov ( DA ) and Density Functional Theory ( DFT ) /Monte-Carlo pore volume distribution utilizing N2 surface assimilation isotherm under liquid N status. Figure 1 illustrates the BJH cumulative surface assimilation pore volume distribution in footings of pore diameter. BJH surface assimilation was counted above the comparative force per unit area 0. 3 at which the self-generated condensation of gas molecule in the cylindrical pores was predicted. As Figure 1. around 85 % of entire pore volume ( 1. 21 mL/g ) belongs to micropore ( pore size 50 A ) . severally for ACC. However. around 48 % of entire pore volume ( 0. 58 mL/g ) belongs to micropore ; whereas 21 % and 31 % of entire pore volume belong to mesopore and macropore size. severally for ACS. The DA method is frequently used to measure the micropore of activated Cs. In the DA equation. there are two variable parametric quantities. ( Eo ) and n. Eo denoted as mean surface assimilation energy. related to the pore diameter and n denoted the breadth of the energy distribution. which was related to the pore size distribution.

The values of N higher than 2 represents the homogenous micropore construction of activated C. while lower than this value represents the heterogeneousness of pores in meso- and macropore scope. As in Figure 2. the upper limit of the micropore volume was much higher for ACC than that of ACS. It implied that the bulk of the pore volume of ACC was related to the micropore construction compared to that of the ACS. It could be more clearly elucidated by the DFT/Monte-Carlo pore size distribution histogram as illustrated in Figure 3. The figure illustrates that the sample ACC preponderantly featured the micropore volume of 12-15 A pore breadth. while it was about one 4th for ACS. The figure besides represents that a minor fraction of pore volume was related to macropore part for ACC. Meanwhile. the pore volume of ACS is distributed in a broad scope of macropore part. Therefore. it could be predicted that the micropore construction of ACC can adsorb methylene bluish dye much more efficaciously than that of ACS. which is discussed in the subsequent subdivisions.

3. 3. Surface functionality

The being of organic functional groups on the activated C surface provides surface mutual opposition. which in bend contributes to surface assimilation belongingss. The figure of open functional groups besides depends on the surface country. Hence the broad surface country with indiscriminately distributed organic functional groups on activated C could presumptively adsorb dye molecule more efficaciously. The functional groups on activated C could be identified by utilizing FT-IR spectrometry. Figure 4 represents the FT-IR spectra of ACC and ACS over the wavelength scope of 4000-450 cm-1. The wide set at 3210 cm-1 for ACC was assigned to OH- stretching quiver. It seems that the set shifted from its usual place at around 3400 cm-1 to take down wavenumber 3210 cm-1 and is excessively wide. implies that the –OH group in ACC was non wholly free but more likely cross-linked. This was due to the fact that. ZnCl2 initiated bond cleavage resulted in desiccation. riddance and cross-linking reactions.

The set at 2900 cm-1 and 1740 cm-1 in natural jute stick was wholly disappeared from the ACC. taking to the important lessening of aliphaticity in the activated C [ 22 ] . The freshly generated set at 1690 cm-1 was attributed to stretching quiver of aryl ketone. while the strong set at 1580 cm-1 ascribed to the C=O stretching of carbonyl group in quinone construction [ 23 ] . The cross linking and condensation of aromatic ring attributed to more condensed polyaromatic ring system. which was attributed to the sets at 1170 and 1070 cm-1 for C-C-C bending. In contrast. the sets with much lower strength were appeared for ACS. This could be due to the release of IR sensitive functional groups and aliphatic groups from ACS because it was treated at high temperature ( 700oC ) .

4. Textural word picture by scanning negatron microscopy ( SEM )

Figure 5 illustrates the Scanning Electron Microscopic images of ACC and ACS. It clearly exhibits the morphological difference of two different activated Cs prepared by different activation methods. The chemical activation method generated a honeycomb type porous C skeleton. while steam activation created pores on the surface far apart from each other. It is obvious that the pore denseness of ACC is much higher than that of ACS. However. as Figure 5. the seeable pore size is in micron scope ( macropore ) . 1000 times higher than that of the nanometers. However. the broad surface country and micropore volume. as revealed from the N surface assimilation survey. were assumed to be the part of micropore size. It seems that. although it is non seeable under the magnification used a broad scope of micropores are indiscriminately distributed on the wall of the seeable pores in ACC.

3. 5. Adsorption of Methylene Blue dye ( MB )

Methylene Blue is one of the representative basic dyes widely used in fabric. soapsuds and paper industries. It is besides used as a theoretical account adsorbate to find the solution stage surface assimilation capacity of C based adsorbent. Figure 6 illustrates the MB surface assimilation isotherm of two different adsorbents as a map of surface assimilation clip at 30 oC. The equilibrium surface assimilation non merely depends on surface assimilation clip but besides depends on the initial concentration of dye solution. The aim of this experiment was to find the maximal MB surface assimilation capacity of both activated Cs in a specific surface assimilation clip. Hence. the initial concentration of dye was relatively higher ( 1000 mg/L ) than that of usual surface assimilation surveies [ 29. 30 ] . As Figure 6. ACS has really limited surface assimilation capacity compared to the ACC. The equilibrium surface assimilation of MB on ACS obtained was 210 mg/g even after 80 h. The equilibrium surface assimilation was attained in 10 H for ACC with much higher surface assimilation capacity ( 470 mg/g ) than that of ACS every bit good as many reported activated Cs [ 30 ] . From the word picture of ACC and ACS. it was revealed that two adsorbents have wholly different structural characteristics with different surface functionality. which could have the different surface assimilation mechanism.

For ACC. most of the MB dye adsorbed on the micropore surface with stronger attractive force force due to the presence of O incorporating polar functional groups. It was besides predicted that the micropores were wholly filled with dye molecules irreversibly. Because of broad micropore surface of ACC with strong attractive force force the equilibrium surface assimilation was much faster than ACS. In contrast. the surface assimilation on the macropore surface with less functional groups of ACS was resulted in weakly forced surface assimilation. The adsorbed MB molecules spontaneously desorbed. and therefore it took longer clip to achieve equilibrium surface assimilation with much lower surface assimilation capacity compared to ACC. Figure 7 illustrates the consequence of temperature on surface assimilation of MB utilizing ACC and ACS. Temperature can impact surface assimilation in two competitory ways. First. it can better the diffusion rate of adsorbate molecules across the external boundary bed and internal pores of the adsorbent. so as to increase the surface assimilation rate and secondly. it can weaken the force between adsorbate and adsorbent. so as to heighten the desorption rate. In MB dye surface assimilation by ACC. the sum of surface assimilation significantly increased with increasing temperature up to around 60 oC. while it was changeless up to 80 oC.

Further addition of temperature resulted in diminishing tendency of surface assimilation. It could be predicted that the diffusion rate preponderantly promoted the surface assimilation rate up to 60 oC and that was about equal to desorption rate in between 60 and 80 oC. Above 80 oC. the desorption rate became outstanding. and therefore the surface assimilation decreased. The surface assimilation of MB molecules on ACS somewhat increased with temperature up to 70 oC. This could be due to the less diffusion opposition for MB molecule to go through macropore channel of ACS. The pH is one of the most of import factors that control the surface assimilation of dye onto adsorbent. As IR surveies. activated C surface possesses some O incorporating functional groups. Those functional groups every bit good as the C in the aromatic ring system of activated C would be influenced by H+ and OH- ions at low and high pH. severally. At low pH. where the H+ ion was dominant in the solution. the species on the surface was assumed to be protonated. and therefore the surface positive charge assumed to be increased.

During surface assimilation of MB. a positively charged dye. the surface charge partly repulsed the dye molecules ; hence the dye consumption was lower at lower pH for both ACC and ACS as shown in Figure 8. As pH increased. the dye consumption increased significantly up to pH 7. For ACC the isotherm remained tableland in between pH 7 to pH 11 ; nevertheless. dye consumption jumped from 300 mg/g to 370 mg/g when pH changed from 11 to 13. It could be predicted that in the scope of pH 7-11. the surface charge remained at zero point charge ( pHZPC ) . where the adsorbent and adsorbate could use their built-in nature in surface assimilation. However. when OH- ion became dominant in the solution at higher pH ( & gt ; pHZPC ) . the adsorptive surface preferentially converted to negatively bear down. Hence. the electrostatic attractive force between positively charged dye molecules and negatively charged activated C surface significantly increased. which attributed to the sudden addition of dye surface assimilation by ACC.

3. 6. Adsorption isotherm
Adsorption of solute from solution influenced by a figure of parametric quantities as discussed in the old subdivisions. Under the suited conditions. the maximal monolayer surface assimilation capacity is an of import index of the quality of an adsorbent. This could be predicted by Langmuir surface assimilation isotherm. which is a most often used equation to qualify adsorbents. particularly activated Cs. The Equation 3 is a additive arrested development of the Langmuir equation used for MB dye surface assimilation utilizing ACC. The maximal monolayer surface assimilation capacity was calculated to be 303 mg/g from the incline of the additive arrested development line. The correlativity coefficient of the additive arrested development line obtained was R2=0. 991. which was extremely important to suit the informations good to the Langmuir equation. The dimensionless separation factor of the equilibrium parametric quantity. RL is the indispensable characteristic of the Langmuir surface assimilation isotherm. which defines the favorable nature of surface assimilation. This can be calculated by the undermentioned Equation 4: [ movie ] …… . ( 4 ) where C0 is the highest initial dye concentration ( mg/L ) of the solution. The favorable value of RL lies between 0 and 1. The experimental value of RL obtained was 0. 0002. taking to the favorable surface assimilation of MB onto the ACC [ 29. 30 ] .

4. Decision
The N surface assimilation surveies revealed that the micropore construction with broad surface country was developed in chemically activated C ( ACC ) . while macropore construction with less surface country was developed in physically activated C ( ACS ) . In add-on the surface functional groups of ACC are more important than that of ACS. The micropore construction with organic functional groups on the surface favoured dye surface assimilation more expeditiously for ACC. At equilibrium. around 480 mg/g MB dye was adsorbed on ACC. while it was much lower for ACS ( 182 mg/g ) . The information of Methylene Blue dye surface assimilation from different initial concentrations of solution was rather fitted to the Langmuir surface assimilation theoretical account. which provided the maximal monolayer surface assimilation capacity. 303 mg/g. The separation factor RL was obtained to be 0. 002 prevarications between 0 and 1. which was favorable value for ACC for efficient surface assimilation of Methylene Blue.

Recognition

This research was financially supported by the Third World Academy of Sciences ( TWAS ) under the undertaking no. : 07-033 LDC/CHE/AS–UNESCO FR: 3240144818 and The Ministry of Science and Information and Communiction Technology ( MOSICT 013A/06 ) . The writers are thankful to the Faculty of Chemical Engineering. Universiti Teknologi Mara for supplying the research lab installations to carry on a major portion of this work.

Mentions

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Figure captions

Fig. 1. Barrett. Joyner & A ; Halenda ( BJH ) cumulative surface assimilation pore volume. ( a ) and cumulative surface assimilation surface country. ( B ) . Fig. 2. Concentrate size distribution measured by Dubinin-Astakhov method for ACC and ACS. Fig. 3. Density Functional Theory ( DFT ) /Monte-Carlo pore volume histogram of ACC and
ACS. Fig. 4. FT-IR spectra of ACC and ACS.

Fig. 5. Scaning electron micrograph of ACC and ACS.
Fig. 6. Consequence of contact clip on Methylene Blue dye surface assimilation on ACC and ACS at 25 oC. Fig. 7. Consequence of temperature on Methylene Blue dye surface assimilation on ACC and ACS. Fig. 8. Consequence of pH on Methylene Blue dye surface assimilation at 30 oC on ACC and ACS.