Synthesis, Characterization of Analcime and its Application in water treatment

from heavy metal

Mohamed Abdul-Moneim¹, Ahmed A. Abdelmoneim², Ahmed A Geies³,   and Seham O. Farghaly¹

¹Geology Department, ³ChemistryDepartment, Faculty of Science, Assiut University, Assiut, 71516, Egypt.

² Geology Departments, Faculty of Science, Sohag University, Sohag, Egypt.

ABSTRACT 

In this study analcime was successively synthesized from kaolinite as a raw material using the fusion with NaOH method. The conditions of hydrothermal crystallization (zeolitization) were found to be at temperature of 170C˚, and time span between 36 h and 72 h for kaoline. The synthetic materials have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric (DTA/TGA) analysis. The results indicate that the crystallization of analcime not affected by the hydrothermal reaction time. The synthetic analcime experimented to up taking some of heavy metals from prepared slandered solution or natural contaminated ground water. The results showed that the synthetic analcime has good efficiency in removal of heavy metals ions (Fe and Mn) with concentrations up to 50 ppm, and Cd and Pb ions to about 10 ppm. The percent adsorption (%) was evaluated with changes in the parameters such as, dosage of adsorpent, PH and time for different heavy metals ions. The order of removal for the different ions is as follows: Pb²⁺ > Cd²⁺ > Mn²⁺ > Fe²⁺. The Langmuir constants model for Fe²⁺ ions sorption on the adsorption isotherms is fitted well. The R_L value in the present investigation at concentration more than 5 ppm was equal or less than one, and equal one for Mn ²⁺, indicating that the adsorption of the metal ion by analcime is favorable. 

Keywords: Analcime, Kaoline, Hydrothermal Reactions, Zeolite, Clay   ground water, aqueous solution, characterization, element contents, water treatment.

INTRODUCTION:

Many toxic heavy metals have been discharged into the environment as industrial wastes, causing serious soil and water pollution (Lin, 2002). Pb^2+, Cd²⁺, Fe²⁺, and Mn²⁺ are especially common metals that tend to accumulate in organisms, causing numerous diseases and disorders (Inglezakis, 2003). They are also common groundwater contaminants at industrial and military installations. Numerous processes exist for removing dissolved heavy metals, including ion exchange, precipitation, phytoextraction, ultrafiltration, reverse osmosis, and electro-dialysis (Thyfault and Mackayla, 2016).The use of alternative low-cost materials as potential sorbents for the removal of heavy metals has been emphasized recently. Various treatment processes are available, among which sorption is considered to be cost-effective if low-cost sorbents such as zeolites are used. (Raeis, et al., 2014). Zeolites are naturally occurring hydrated aluminosilicate minerals. They belong to the class of minerals known as “tectosilicates. Most common natural zeolites are formed by alteration of glass-rich volcanic rocks (tuff) and alkaline rocks. Analcime is a hydrated sodium aluminum silicate which exists in cubic crystals. The chemical formula of analcime is NaAlSi2O6·H2O.(Gatta et al., 2004), with small amount of potassium and calcium. The structure and chemical properties are more similar to the feldspathoids, even though they are classified to the zeolite mineral. Natural analcime can be found in the analcime basalt and other alkaline igneous rocks. Analcime can be used as an ion-sieve (Fabbrizio et al., 2008).One of the analcime characteristics is exchange ions at room temperature, and increasing temperature make the ion-exchange more easily. This is due to the presence of smaller pores in analcime structure (Azizi et al., 2013). Generally, zeolite minerals are rare in all of the world, therefore over 200 synthetic zeolites have been synthesized either using chemicals or natural materials. The main objective of this study focused on utilization of the low cost and abundance materials such as clay (kaolinite)for synthetic analcime, and used it  to remove heavy metal ions such as Fe^2+, Mn²⁺, Pb²⁺  and Cd²⁺ from prepared standard solutions and natural ground water from Wadi Qena area.

1. HYDROGEOLOGICAL SETTING OF WADI QENA

        Wadi Qena is located in the north part of the Eastern Desert.It lies between latitudes 26⁰10` and 28<sup>0</sup>15` N, and longitudes 32⁰31` and 32<sup>0</sup>45` E Fig. (1). Most of the hydrogeological studies that have been carried out in wadi Qena were focused mainly on the downstream of the wadi Among these studies; El-Ramly 1972, Gomaa 1992; Thorweihe et al. (1993); Aggour 1997; Assiut University 2001; Yehia A.  2001; Abdel Moneim 2005; Seleem 2014; Abdel Moneim et al. (2015). The review of the pervious publications indicated that groundwater in Wadi Qena and its surroundings exist with different potential in six aquifers under different hydrogeological conditions. These units are; quaternary Alluvium aquifer, Pliocene Sandstone aquifer, Lower Maestrichtian phosphate aquifer, Companion Marl aquifer, Turonian–Santonian Sandstone aquifer, Precambrian Basement Complex aquifer. Also,   the groundwater in the study area can be classified into shallow and deep. Shallow groundwater aquifers occur mainly within the Quaternary alluvial sediments. The main recharge is from the local rainfall and flash floods that occur due to short-period heavy storms falling on the mountainous zones and sedimentary hills. Recharge from the deep aquifers through subsurface joints and fractures, as well as from the Nile aquifer, could be expected,. The deeper aquifer is in Nubian sandstone and is potentially good for agriculture. Its thickness ranges from 300m to 800 m. At relatively shallow depths (less than 500 m), the groundwater is brackish (total dissolved solid; TDS more than 4876 ppm). However, at greater depths (more than 500 m), the groundwater is fresh (TDS of 580; Rashed et al., 2006).The study of hydrochemical characteristics in Wadi Qena revealed on the high concentration of Fe and Mn in some studied wells relative to (WHO, 2004) and (A.R.E, 2007).

Fig. (1):  Location map of the Wadi Qena

3. METHODOLOGY

Two method were used to synthetic of analcime using kaolinite raw material as a source of Al and Si. The chemical composition of the raw material kaolinite are given in Table (1)

Table (1).Chemical composition of kaolinite

1. By using alkaline fusion (after Rios et al, 2008)to synthetic analcime using kaolinite NaOH pellets was mixed with the calcinated Kaoline by ratio 1.2: 1 and the mixture was fused at 600C˚  for 1 h . The alkaline reagent added to the starting material acts as an activator agent during fusion. The alkali-fused products were then dissolved in water (H2O/alkali fused starting material ratio )=(1:4.9), generally under stirring conditions until the reaction gels were homogenized aged for 24 h under static conditions. The mixtures were transferred into polytetrafluoroethylene (PTFE) bottles of 200 ml and a stainless steel autoclave, then crystallized under static conditions at 170 C˚ for 5, 3, 1.5, days .After removal from the oven they were quenched in cold water and the product recovered by vacuum filtration, washed well with distilled water until the pH reach up to 11 and dried at 80C˚ overnight.

2. Analcime was synthesized through a hydrothermal method using the following reaction condition:

6Na2O: 0.75Al2O3:30SiO2. 780H2O.At first, 4.75g of sodium hydroxide were dissolved in 10 g water. To this solution about 3.575 of kaolinite were added. The mixture was stirred (200-300 rmp), thereafter 161.25 g of water were added and stirred.   The gel was then transferred to polytetrafluoroethylene (PTFE) bottles (200 ml) and a stainless steel autoclave, then put in oven at 170 C˚ for 36h.After removal from the oven, quenched in cold water, and the product recovered by vacuum filtration, washed with distilled water and dried at 80 C˚ overnight.The synthetic zeolite was identified and characterize by the next measurements. The X-ray diffract graphs of the raw material and synthetic zeolite were obtained by using X-ray diffraction pattern, recorded on a Philips Expert (30 mA, 40 kV) with CuKα radiation, The morphologies of the raw material and synthetic zeolite were examined by scanning electron microscopy (SEM using a Jeol JSM-5400 LV instrument. SEM sample was prepared on a copper holder by placing a smooth part of the Zeolites powder and then covered with gold–palladium alloy. SEM images were taken using a Penta Z Z-50P Camera with Ilford film at an accelerating voltage of 15 kV using a low-dose technique.,FT-IR spectra were recorded on IR-470, Infrared spectrophotometer, Shimadzu by using the KBr pellet technique. And thermo gravimetric analysis (TGA) and differential thermal gravimetric (DTG) were carried out in air with Shimadzu DTG-60 at heating rate of 10°C/min.

4. RESULTS AND DISCUSSION

    4.1. CHARACTERIZATION

       1. X-RAY DIFFRACTION

The identification and characterizations of the raw material and synthetic zeolite shown in fig.(2). a 2θ range of 5-55°.Kaoline is the predominant mineral phase in the raw material which can be identified by its characteristic XRD peaks at 12.34° and 24.64° 2θ Fig.(2a). However, minor mineral impurities, such as quartz, illite, muscovite and halloysite, also occur. The X-ray diffractgrams of the synthesized give reflection peaks at 15.76˚, 25.93˚ and 30.48˚As shown in the XRD patterns Fig. (2b), which is consistent with the analcime (see Treacy and Higgins, 2001; Zhao et al., 2004).

Fig.(2): XRD patterns of a) Raw material kaolinite b)Synthetic analcime

2. SCANNING ELECTRON MICROSCOPE (SEM)

The morphology of the raw material and synthetic zeolite were examined shown in Fig. (3 a, b). The main morphological features observed in the synthesized analcime from met kaolinite are, spherical and cubical Fig.(3 a, b).

Fig. (3). SEM micrographs of (a)   Raw material kaolinite ;(b) Synthetic analcime

FOURIER TRANSFORM INFRARED (FT-IR) SPECTROSCOPY

The characterization of raw material (kaolinite) and synthetic analcime with transmission Fourier transform infrared spectroscopy (FT-IR) is described in Table (2), Fig. (4 a, b).The characteristic OH-stretching vibrations of kaolinite band at 3460.71 cm^–1 .The symmetric stretch (753-71 cm⁻¹), double ring vibration (63-44 cm⁻¹), T-O bending modes (44.04 cm⁻¹),or  the internal linkage vibrations of TO4 (T=Si or Al) tetrahedral and to symmetrical stretching respectively. The bands at (1677 .26 cm⁻¹) is assigned to the water in the channels of kaoline.FT-IR spectroscopy is used to probe the structure of the synthesized Analcime and monitor reactions in zeolite pores. Specifically, structural information can be obtained from the vibrational frequencies of the zeolite lattice observed in the range between 200 and 1500 cm⁻¹, (Li., 2005). In general, each zeolite has characteristic infrared pattern.  However, some common features are observed which, include the asymmetric (950 - 1250 cm⁻¹) and symmetric stretch (660 - 770 cm⁻¹), double ring vibration (500 - 650 cm⁻¹), T-O bending modes (420 – 500 cm⁻¹), and possibly opening modes (400 - 420 cm⁻¹). The FT-IR-spectral data of the synthesized analcimeis presented in (Fig.4b).The double rings (D4R and D6R) in the framework structures of the zeolitic (500 - 650 cm⁻¹), is near to 653 (s) cm⁻¹, which is characteristics Analcime, (Rios et al., 2008).The bands at 462 (s) cm^–1 of analcime, is  near the absorption bands within the range 420–500 cm⁻¹ which are related to the T–O–T bending of vibration mode (T = Al, Si) respectively. These absorption bands characterizing T-O bending vibrations may shifted to lower frequencies due to decreasing Si/Al ratio inthe internal linkage due to the different length of the Al-O and Si-O bands. (Li.,2005),(Mohammed et al., 2013).The band 724 (s) cm^–1 of analcimeis near from the bands in the range 720–790 cm^–1is  associated with symmetric stretching vibration of 4-membered rings. Fig. (4b). this band should be assigned to the 4-membered ring vibrations. Because these rings contain the lowest number of members of all rings occurring in the zeolite structure, therefore the bands due to these rings occur at relatively high wave numbers in the pseudo lattice band range (Wang et al.,  2006). The band1650 (w), of analcime, is  near the bands at 1647 and 1648 cm (Lewis sites) region is assigned to the zeolitic water in the channels of zeolite (Blanco et al., 1989). The bands at spectra 3446, 3460 and 3482 are attributed to the asymmetric stretching mode of molecular water coordinated to the edges of the zeolite channels (Zhao et al., 2006; Faghihian et al., 2009) and the band 3602 cm^–1 of analcime is near thebands that are attributed to the asymmetric stretching mode of molecular water coordinated to the edges of the zeolite channels (Zhao et al., 2006; Faghihianet al., 2009). The bands that located at the lowest wave numbers466 and 377 cm^–1, arecorresponding to the characteristic bendingvibrations carried out in the 4-membered rings. Table (2), (Mozgawaet al., 2005).

Fig. (4) Fourier transforms infrared spectroscopy (FT-IR) 0f. (a)  Raw material kaolinite ;(b) Synthetic analcime

Table (2): Fourier Transform Infrared (FT-IR) Spectroscopy of Synthetic analcime

4. THERMAL GRAVIMETRIC ANALYSIS (TGA) OF THE SYNTHESIZED ZEOLITES

The thermal behavior of synthesized analcime (TGA) and (DTG) are shown in Fig. (5). The synthesized product show up to four dehydration steps. The position of these DTG peaks and the number of dehydration steps can be attributed to the different compensating cation-water binding energies.  As well as to the different energy associated with the diffusion of the desorbed water through the porous structure of the synthesized product.  Their weight loss percentages reflect the water loss from the zeolite structure, and the amount of desorbed water is related with the number of compensation cations in the framework of the zeolite. (Reyes et al., 2013).The peaks observed between 39-52 °C correspond to surface water in zeolitic materials; the peaks observed between 100 and162 °C indicate zeolitic water, although in some cases in this temperature range up to two peaks occur, which can be explained by the heterogeneous nature of the synthesized product.  TGA curves also, showed a small weight loss in the range 0-2 % starting at 90°C until 150°C which may be attributed to loss of observed moisture and entrapped solvents. The thermographs of analcime are given in Fig. (5)

Fig.(5).  Thermal analysis of the synthesized Analcime

4.2. ADSORPTIVE PROPERTIES OF THE SYNTHETIC ANALCIME

Batch adsorption studies

A batch adsorption experiment was conducted due to its simplicity In order to investigate the efficiency of the synthetic analcime in removal of some heavy metal. The experiments operated into natural ground water samples from Wadi Qena which contaminated by Fe and Mn.  In addition to Fe and Mn, standard solution with concentration range from 5 to 50 ppm were prepared for Cd and Pb, by dilution Merk chemical standard solution (1000 ppm).The uptake of Cd (II), Pb (II), Fe (II) and Mn (II) onto zeolites as a function of their concentrations was studied at room temperature, by varying the metal concentration from 5 to 50 mg/L and time while keeping all other parameters constant with respect to dose.

1. Effect of Studied analcime Dosage

The removal of Cd(II), Pb(II), Fe(II) and Mn(II) as a function of analcimedosageat the metal concentration from 5ppm,the solution pH 6-.6.5,analcime dosage was varied from 0.1 to 1 g and equilibrated for 1 hrs. Increasing analcime dosage increased the percent removal of Cd(II), Pb(II), Fe(II) and Mn(II).And The results show that the optimum dosageis0.5g, also The results clearly indicate the removal efficiency don't increase up to the optimum dosage Fig.(6). 

Fig.(6).  Effect of Studied analcime dosage on adsorption of metal ions

2. Effect of metal ions concentration

Theuptake of metal ions (Cd, Pb, Fe and Mn) onto analcime as function of their concentrations was studied at room temperature and analcime dose equal 0.5 g, by varying the metal concentration from 5 to 50 mg/L, while keeping all other parameters constant. The results are given in Fig. (7).Percentage adsorption for Fe and Mn decreases with increasing metal concentration in aqueous solution Fig (7). These results indicate that the order affinity of analcime   for reducing the studied heavy metals ions  as follows Pb²⁺> Cd²⁺> Mn²⁺> Fe²⁺ .The heavy metals uptake may be attributed to different mechanisms of ion-exchange as well as the adsorption processes.(Ibrahim,et al.,2010).

Fig. (7)Effect of initial concentration on adsorption of metal ions by studied analcime

3 .Effect of contact time

The effect of contact time on adsorption of Fe²⁺and Mn²⁺ was examined at metals concentration 50ppm 0.5 g of the synthetic analcime , at room temperature and pH(6-6.5) for each ion with time varying between   5 and  60min Fig.(8) The results show that the optimum contact time for Fe is 30 min, and 60 min for MnFig.(8)

Fig. (8).Effect of contact time on adsorption of Fe²⁺, Mn²⁺ions by analcime

4.3. REMOVAL OF (FE2+, MN2+) IONS FROM GROUND WATER SAMPLES AT WADI QENA

The concentration of Fe and Mn in the ground water samples from Wadi Qena were 5.5 ppm and1 ppm respectively.The synthetic analcime was applied in the removal of heavy metals (Fe²⁺, Mn²⁺) ions from ground water samples from wadi Qena. The sorption studies were carried out at different pH from 4.5- to 10.5, and time between 5 to 180 min. The optimum conditions for sorption of Fe and Mn were found at pH (6-6.5) and time at 60 min, using constant dose 0.5 g. The results are shown in Table (3).

Table (3) Heavy metal removal (%) by the studded zeolite for ground water samples from wadi Qena

From the above table it was noted that the synthetic zeolite analcime was found to be very effective in removing almost (Fe²⁺, Mn²⁺) ions from the studied samples. A selectivity series can be determined for analcime: Fe²⁺>Mn²⁺. It is noted that from table (3) and Fig. (8)The percentage of metal removed of (Fe²⁺, Mn²⁺⁾ ions from the studded samples is smaller than its percentage from the standard solutionat the same conditions. This is due to the effect of Effect of competitive metal ions (Qin et al. 2006 and Sewwandi et al. 2014).

4.4. REMOVAL MECHANISM a1-The structures of zeolites consist of three-dimensional frameworks of SiO₄ and AlO₄ tetrahedral. The aluminum ion is small enough to occupy the position in the center of the tetrahedron of four oxygen atoms, and the isomorphous replacement of Si⁺⁴ by Al⁺³ produces a negative charge in the lattice. The net negative charge is balanced by the exchangeable cation (sodium, potassium, or calcium). These cations are exchangeable with certain cations in solutions such as lead, cadmium, zinc, and manganese (Khachatryan, 2014). The fact that zeolite exchangeable ions are relatively innocuous (sodium, calcium, and potassium ions) makes them particularly suitable for removing undesirable heavy metal ions from industrial effluent waters.

• Ion exchange:  Zeolitesare capable of exchanging ions with external medium, which is the significant characteristic of zeolite. Ion exchange proceeds in an isomorphous fashion. The equilibrium ion exchange is expressed by the following equation (1)

zBA^Z+A + zABLzB⇔zAB^z+B + zB^ALzA (1)

wherezA⁺ and zB⁺ are the valences of the respective cations, and L is defined as a portion of zeolite framework holding unit negative charge. Many zeolitescontain several crystallographically distinct sets of sites that can be occupied by exchangeable ions. These sets of sites are intimately mixed with one another throughout the crystal, and each may exhibit different selectivities and ion-exchange behavior. The number of available exchange sites commonly exceeds the number of negative charges to be neutralized. Hence, the anionic charge of the framework may be neutralized when only some of the sites are occupied, and the occupancy factors may vary with the nature of the neutralizing cation. (Pabalan et al., 2001).  In addition, the entering ion does not necessarily take the position of the leaving ion (Pabalan et al., 2001).    (Sherry and Howard, 2003). Thus, the zeolites may exhibit a high degree of cationic disorder, both in terms of unoccupied sites and in terms of different distributions of cations of different kinds among the site groups.Adsorptionof heavy metal ions is a special characteristic of zeolites. The amount of metal adsorbed is affected by conditions like the nature and concentration of counter ions, pH, and metal solubility. (Hua et al., 2012).

• Also.  The heavy metal uptake is attributed to different mechanisms of ion-exchange processes as well as to the adsorption process.
• So that according the above expressionsand  the chemical composition of kaolinite (Tab.1), which considered the original material that enter  in the synthesis analcime  (The nature and concentration of counter ions).Analcime has affinity for heavy metals(Fe²⁺, Mn²⁺ , Cd²⁺ and Pb²⁺)up taking and as well as the ion-exchange process.,

2-Most Common Ions will exchange readily into most zeolites. However, the ion sievingeffect is observed with the zeolites having the smallest pore openings and with the largest cations. For example Rb⁺ (3.0 Å diameter)will slowly enter analcime but Cs⁺(3.4 Å diameter) will not, suggesting that analcime has an effective pore size of~3.2 Å. So that the preference of these zeolites (analcime) for Pb²⁺ compared to the others (Tab.6).This is usually attributed to differences in metal characteristics and resultant affinity for sorption sites (Appel et al., 2002). For example, the hydrated radius of Pb⁺²is smaller than that of Cd²⁺, Mn²⁺and Fe²⁺As shown in table (3). Zeolites, in general, are weakly acidic in nature andsodium-form exchangers are selective for hydrogen (R–Na+H2O ⇔RH + Na+ + OH−), which leads to high pH valueswhen the exchanger is equilibrated with relatively diluteelectrolyte solutions (Wei, et al., 2006). Making metal hydroxide precipitationfeasible. In natural zeolites these metals seem to reachsaturation, which means that the metal had filled possibleavailable sites and further adsorption could take place onlyat new surfaces. Ion-exchange capacity of heavy metal cations listed in Table (4). indicates the following selectivity sequence: Co²⁺> Cu²⁺> Zn²⁺> Mn²⁺. The heavy metal cations are present as hexaaqua complex ions with six surrounding water molecules in the solution and they passed the channel of zeolite in this form (Erdem et al., 2004). Since the adsorption phenomena depend on the charge density of cations, the diameter of hydrate cations is very important. The charges of the metal cation are the same (²⁺); therefore Mn²⁺ ions (the biggest diameter) have minimum adsorption, and Pb²⁺ ions (the least diameter) have maximum adsorption.

Table (4).Hydrated ionic diameters of heavy metals (adapted from Nightingale. (Abdul et al., 2011)

Metal ion

Hydrated ionic diameter (nm)

Pb

0.401

Cd

0.426

Mn

0.83

Fe

0.77

4.5. ADSORPTION ISOTHERMS OF FE2+, MN2+, CD2+ANDPB2+ IONS BY SYNTHETIC ZEOLITES

The equilibrium adsorption of the Fe²⁺, Mn²⁺, Cd²⁺ and Pb²⁺Ions  were  carried out by contacting 0.5g of the previous synthetic zeolites with different concentrations (5, 10, 15, 50) ppm from Fe⁺² and Mn⁺² Ions and (5, 10, 15) ppm from Cd^{+ 2} and Pb^{+ 2}Ions under room temperature, for  l h .and at pH (6-6,5) .on the shaker. The mixture was filtered and the filtrate analyzed for the metal ions concentration using AAS. and the data was fitted into the following isotherms: Langmuir, Freundlich,

1. A.     Langmuir Adsorption Isotherm

Adsorption isotherm data are quantified to describe the interactions between the adsorbate and adsorbent and are critical in optimizing the use of adsorbent (Gupta et al., 2003). The Langmuir equation is the mostpopular of all the nonlinear isotherm expressions; it is a two-parameter equation (2).

(2)

Where constants b and qm relate to the energy of adsorption and adsorption capacity and their values are obtained from the slope and intercept of the plot of Ce/qe versus Ceforroom temperature. Langmuir adsorptionparameters were determined by transforming the Langmuir equation (3) into linear form.

Where:

Ce = the equilibrium concentration of adsorbate (mg/L^-1)

qe = the amount of metal adsorbed per gram of     the adsorbent at equilibrium (mg/g).

Qo = maximum monolayer coverage capacity (mg/g)

K_L = Langmuir isotherm constant (L/mg).

The values of q max and K L were computed from the slope and intercept of the Langmuir plotof1/ qe versus 1/CeFig. (9).(Ji,  et al., 2013).Moreover the characterization of the Langmuir equation can be explained in terms of the equilibrium parameters (R_L)   which is a dimensionless constant referred to as separation factor or equilibrium parameter equation (4).

( Pandey et al., 2010).                    R_L=1/1+ (K_L+C₀ )        (4)

Where:

C₀ = initial concentration,K_L = the constant related to the energy of adsorption (Langmuir Constant).

R_Lvalue indicates the adsorption nature to be either unfavorable if R_L>1), linear if R_L =1, favorable if 0< R_L<1 and irreversible if R_L=0.

Fig. (9). Langmuir Adsorption Isotherm for adsorption ofFe²⁺ and Mn²⁺

.From the correlation coefficient (R²) values that are regarded as a measure of the goodness fit of experimental data on the isotherm’s model. And Table (5)

Table (5).Correlation factor for shape of isotherm

From the previous Table(5)The Langmuir isotherm is favorable  model for Fe²⁺, Mn²⁺ and Cd²⁺ ions sorption systems by using analcime, because of  R² value for Fe⁺², Mn⁺²and Cd⁺² is 0.96, 0.8 and 0.99, respectively proving that the sorption data fitted well to Langmuir Isotherm modelAnd  value 0 < R < 1.0. Also, it noted that and R²of Cd⁺²ionis the largest indicating that  using  the synthetic analcime for removal Cd⁺² ion is morefit of experimental data on the isotherm’s model. Also, the value of R_L that describes the nature of the adsorption: irreversible (R_L = 0); favorable (0 < R_L< 1); linear (R_L = 1); unfavorable (R_L> 1) (Rozada et al., 2007). From the data calculated in Table (8), in the case of Fe²⁺, Mn²⁺ and Cd²⁺ ions are favorable (0 < R_L< 1); AndFrom this research work, the maximum monolayer coverage capacity (Qo) from Langmuir Isotherm model was determined to be 10.6,57.5 and 99.6mg/g, for Fe²⁺, Mn²⁺ and Cd²⁺ ions respectively and   K_L (Langmuir isotherm constant) is 0 for the previousions.This again confirmed that the Langmuir isotherm was favorable for sorptionofFe²⁺, Mn²⁺ and Cd²⁺ ions onto the synthetic zeolites (analcime) under the conditions used in this study (Unlu et al.,  2006). (Zhanga et al.,  2000). Anfortiontly from the data Tables (6), (7) it noted that although the removal (%) of Pb²⁺ ion by using the synthetic zeolites (analcime)  is the highest but Pb²⁺ ion  does not obeyed the  Langmuir isotherm.

Table (6): Parameters for plotting Langmuir, Freundlich, Adsorption Isotherms of Fe⁺²,Mn⁺² and Cd⁺²ions by the synthetic zeolites

Table (7): Linear regression equations Langmuir and Freundlich isotherm and constants for adsorption of Fe⁺², Mn⁺² and Cd⁺²ionson the synthetic zeolites

Table (8) RL values for Fe⁺², Mn⁺² and Cd⁺²ions concentrations

B. Freundlich Adsorption Isotherm

This is commonly used to describe the adsorption characteristics for the heterogeneous surface (Hutson et al., 2000). This equation predicts multilayer adsorption on heterogeneous surface, characterized by an exponential distributionof active sites.These data often fit the empirical equation (5) proposed by Freundlich:

Qe =K_f C_e^1/n        (5)

Where

Kf = Freundlich isotherm constant (mg/g)

n = adsorption intensity;

Ce = the equilibrium concentration of adsorbate (mg/L)

Qe = the amount of metal adsorbed per gram of the adsorbent at equilibrium (mg/g). Linearizing equation (6).

We have:          

logQ_e= log K_f+1/n log C_e            (6).

The Freundlichcoefficientsk_F and n corresponding respectively to adsorption capacity and adsorption intensity have been obtained fromthe intercepts and slopes of linear plots log Qe against log Ce (Fig. 10).Specifically, the linear least-squares method and the linearly transformed equations have been widely applied to correlate sorption data where 1/n is a heterogeneity parameter, the smaller 1/n, the greater the expected heterogeneity. This expression reduces to a linear adsorption isotherm when 1/n = 1. If n lies between one and ten, this indicates a favorable sorption process (Goldberg et al., 2005)and if the values of n were lower than one indicating the adsorption is less favorable

Fig. (10).Freundlich Adsorption Isothermplot for adsorption ofFe²⁺ and Mn²⁺

For the above Fig. (10).and from the calculated results  ofFe²⁺,Mn²⁺ and Cd²⁺ionsit was found n were lower than one indicating the adsorption is less favorable adsorption by using synthetic zeolite (analcime). On the other hand, 1/n being above one in the case of Fe²⁺ and Mn²⁺ions indicates cooperative adsorption and less favorable (Etale et al., 2016).but1/n was the smaller than one in the case of Cd²⁺ion indicating  the greater the expected heterogeneity.And  favorable sorption. Also the R²value for Fe²⁺, Mn²⁺ and Cd²⁺ions are 0.3,-0.1 and -3.1 respectively and it was demonstrated that the removal of Fe⁺², Mn⁺² and Cd⁺²ions using thesynthetic zeolite (analcime ) did  not obeyed the  Freundlich isotherm(Goldberg et al.,  2005). From the previous data in Table (5) it noted that although the removal (%) of Pb²⁺  ion by using the synthetic zeolites (analcime)  is the highest but Pb^{+ 2} ion  did not obeyed the  Freundlich isotherm.From the correlation coefficient(R²) values in Tables (9) it was noted that,R² value ofFe²⁺, Mn²⁺ and Cd²⁺ions  are 0.96, 0.88 and 0.99 respectively  for theLangmuir isotherm adsorptionmodel and was  higher than R2value for the Freundlich model of Fe²⁺, Mn²⁺ and Cd²⁺ ions  that  are 0.3 ,- 0.1 and- 3.1, respectively so that the experimental data for the adsorption processhad better correlation coefficients values and better fits with the Langmuir isotherm model Fig. (9)than with the Freundlich model Fig. (10). Therefore, the adsorption process of Fe²⁺, Mn²⁺ and Cd²⁺ions onto the synthetic zeolite (analcime). Was foundto follow the Langmuir isotherm model with a maximum monolayer adsorption capacity (10.6, 57.5 and 99.6) (mg/g) of Fe²⁺, Mn²⁺ and Cd²⁺ions, respectively. These results revealed the anchoring of Fe²⁺, Mn²⁺ and Cd²⁺ions  to the abundant functional groups onto the synthetic zeolite (analcime )with the formation of monolayer surface coverage that was homogeneous in nature (Fernandez et al., 2003).

CONCLUSION.

Ground Water pollution with heavy metals and their purification acquires increasingimportance for the development of modern industry. Higher levels of heavy metals in aquatic facilities pose a major risk to human health. It is therefore important to find ways to abate or remove such pollutantsfrom ground water used for drinking water.In this study  someheavy metals such as (Fe^+2, Mn⁺², Pb⁺²  and Cd⁺²) was reduced from synthetic solution and natural ground water by synthetic of analcime. The use of zeolites as adsorbent are often preferred due to their specific structure, which allows the selectivity of the processes involved (adsorption and ion exchange), and relatively simple operation with them and efficiency. Analcime was successively synthesized from kaolinite as a raw material using the fusion with NaOH method. The conditions of hydrothermal crystallization (zeolitization) were found to be at temperature of 170˚C, and time span between 36 h and 72 h for kaoline. The synthetic materials have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric (DTA/TGA) analysis. Also, it was employed in solution for the removal of(Fe^+2, Mn⁺², Pb⁺² and Cd⁺²) ions. It was found analcime has good efficiency in removal of heavy metals ions ( Fe and Mn) with concentrations up to 50 ppm, and Cd and Pb ions to about 10 ppm.

The content of ions have been decreased in aqueous solutions during Batch methods of purification.

More than 92%of lead, Manganese  and iron ions have been sorbed by analcime, The order of removal for the different ions is as follows: Pb⁺²  > Cd^{+ 2} > Mn⁺² > Fe^{+ 2} . The experimental data for the adsorption process of Fe⁺², Mn⁺² and Cd⁺²ions onto analcime had better correlation coefficients values and better fits with the Langmuir isotherm modelthan with  the Freundlich model .

REFERENCES.

• Abdel Moneim A.A. (2005):  Hydrogeological Conditions and Land Suitability for Development on the Area Surrounding the Proposed New Road Between Sohag and the Red Sea, Wadi Qena, Eastern Desert , Egypt. The fourth international conference on the geology of Africa,Assiut University Vol. (2) pp 17-41 Nov. 2005.
• Abdel Moneim, A. A.  (2013); Hydrogeological conditions and aquifer potentiality for sustainable development of the desert areas in Wadi Qena, Eastern Desert, Egypt .Journal of Arab geosciences Vol.7 issue 11 pp 4573-4591.
• Abdul M. Z.,Parvez M.*, Ashantha G.,Moses O. A.,Serge K., Adekunle O.(2011): Influence of Physical and Chemical Parameters on theTreatment of Heavy Metals in Polluted Storm water Using Zeolite—A Review Journal of Water Resource and Protection, vol., 3, pp.758-767
• Appel, C. and Ma, L. Q. (2002): “Concentration, pH, and surface charge effects on cadmium and lead sorption in three tropical soils Journal of Environmental Quality, vol. 31,(2), pp. 581-589,
• Azizi, Seyed N. T., Salma E.(2013): Cu-modified analcime as a catalyst for oxidation of benzyl alcohol: experimental and theoretical. Journal Micro porous and Mesoporous Materials, vol. 167.pp. 89-93
• Bandel, K., Kuss, J., and Malchus, N., (1987): The sediments of Wadi Qena (Eastern Desert, Egypt).Journal of African Earth Sciences,vol. 6 (4),pp. 427–455.
• Blanco, C., Gonzalez, F., Pesquera, C., Benito, I., Mendioroz, S. Pajares, J.A.. (1989): Differences between One AluminicPalygorskite and another Magnesic by Infrared Spectroscopy. Journal of Spectroscopy Letters, vol.22, (9,pp 659-673
• Etale, Anita T., Hlanganani D., Deanne C. ( 2016) : Application of maghemite nanoparticles as sorbents for the removal of Cu (II), Mn (II) and U (VI) ions from aqueous solution in acid mine drainage conditions,journal Applied Water Science ,vol.6(2),pp. 187-197
• El Ramly, M. F., (1972):A new geological map for the basement rocks in the eastern and south western desert of Egypt, annals, geol. Surv., Egypt., Vol.. II: pp. 1-18
• Erdem, E. Karapinar, N. and Donat, R. (2004): “The removal of heavy metal cations by natural zeolites”. Journal of Colloid and Interface Science.vol. 280, pp. 309–314,
• Fabbrizio, Alessandro S., Max W G., Detlef E., Jost.(2008):  Experimental determination of radium partitioning between leucite and phonolite melt and 226 Ra-disequilibrium crystallization ages of leucite,journal  Chemical Geology ,vol. 255(3),pp. 377-387
• Faghihian, H. and Godazandeha, N. (2009): Synthesis of Nano Crystalline Zeolite Y from Bentonite. Journal of Porous Materials, vol. 16 (3), pp. 331-335.
• Fernandez, E., Hugi-Cleary, D., López-Ramón, M V., Stoeckli, F.,.(2003) :Adsorption of phenol from dilute and concentrated aqueous solutions by activated carbons ,JournalLangmuir, vol.19  , (23) , pp. 9719-9723
• Gupta, Vinod K J., Ali CK, Imran S., Saini M, VK.(2003) :"Saini Removal of cadmium and nickel fromwastewater using bagasse fly ash—a sugar industrywaste Water Research, vol. 37(16), pp.4038–4044
• Gatta, G Nestola, Fabrizio B., Tiziana B. (2004): Elastic behavior, phase transition, and pressure induced structural evolution of analcime, journal American Mineralogist , vol.91(4),pp. 568-578.
• Goldberg, Sabine T., MA Sparks, DL Al-Amoodi, L Dick, WA (2005): Equations and models describing adsorption processes in soils, Journal Soil Science Society of America Book Series  ,vol. 8, pp. 489
• Gomaa (1992): Hydrogeological studies between Qusier-Safaga area, Eastern Desert, Egypt. MSc. thesis, Faculty of Science AinShams University, Egypt 150p
• Hutson N.D.  And R.T. Yang. (2000): Influence of Residual Water on the Adsorption of Atmospheric Gases in Li− X Zeolite: Experiment and Simulation Journal, Industrial & Engineering Chemistry Research ,vol. 39, (6), pp. 1775-1780
• Ibrahim, Hanan S J., Tarek S H., Eman Z. (2010): Application of zeolite prepared from Egyptian kaolin for the removal of heavy metals: II. Isothermmodels. Journal of Hazardous Materials,vol.182 (1), pp. 842-847
• Inglezakis, VassilisJ L., Maria D G., Helen P (2003): Ion exchange of Pb +2, Cu +2, Fe +3, and Cr + 3on natural clinoptilolite: selectivity determination and influence of acidity on metal uptake ,Journal of Colloid and Interface Science Vol. 261(1), pp.49-54.
• Ji, Liqin B., Xue Z., Lincheng S., Hanchang C., Wei H., Zulin (2013): One-pot preparation of graphene oxide magnetic nan composites for the removal of tetrabromobisphenol a.journalFrontiers of Environmental Science & Engineering,vol.7(3),pp. 442-450
• Khachatryan, Sh V. (2014): Heavy metal adsorption by Armenian natural zeolite from natural aqueous solutions.journal Chemistry and Biology.vol. 2, pp31-35
• Li, G. (2005): FT-IR Studies of Zeolite Materials: Characterization and Environmental Applications. Ph.D. Thesis, Graduate College, the University of Iowa, Iowa City, 162.
• Lin, Su-Hsia J., Ruey-Shin.(2002) :Heavy metal removal from water by sorption using surfactant-modified montmorillonite Journal of Hazardous Materials, vol. 92 (3),  pp. 315-326
• Mohammed, A.A., Shakir, I.K. and Esgair, K.K. (2013): The Use of Prepared Zeolite Y from Iraqi Kaolin for Fluid Catalytic Cracking of Vacuum Gas Oil. Journal of Engineering, 19, 1256-1270.
• Mozgawaet W., Jastrzębski W., Handke M.(2005) :Vibrational spectra of D4R and D6R structural units. Journal of Molecular Structure, vol. 744, pp. 663–670.
• Pabalan, Roberto T Bertetti, F Paul.(2001) : Cation-exchange properties of natural zeolites journal  Reviews in mineralogy and geochemistry vol.  45 (1) pp. 453-518
• Pandey, Sharma PK, Sambi SK, SS.(2010):  Kinetics and equilibrium study of chromium adsorption on zeoliteNaX, International Journal of Environmental Science & Technology, vol.7 (2), pp. 395-404
• Raeis H., Niloufar L., Jang-Sik. (2014):Resistive switching memory based on bioinspired natural solid polymer electrolytes, Journal ACS nano,vol.9 (1), pp. 419-426
• Rashed, M., Idris, Y., and Shaban, M.          (2006): Integrative approach of GIS and remote sensing to represent the hydrological and hydrochemical conditions of Wadi Qena-Egypt. In: The 2nd international conference on water resources and arid environment, 26–29 November, Cairo, Egypt. Egypt: Research Institute for Groundwater, National Water Research Center.
• Reyes, Carlos Alberto Ríos Williams, Craig Alarcón, Oscar Mauricio Castellanos (2013): Nucleation and growth process of sodalite and cancrinite from kaolinite-rich clay under low-temperature hydrothermal conditions. Journal Materials Research, 16.(2): 424-438.
• Rios R., Carlos A. (2008): Synthesis of zeolites from geological materials and industrial wastes for potential application in environmental problems
• Ríos, C.A, Williams, C.D.(2008 : Synthesis of zeolitic materials from natural clinker: A new alternative for recycling coal combustion by-products. Journal Fuel 87, pp. 2482-2492
• Rozada, F.; Otero, M.; García, A.I.; Morán (2007): Application in fixed-bed systems of adsorbents obtained from sewage sludge and discarded tyres,JournalDyes Pigment,vol. 72, ,(1), pp.47–56.
• Seleem E. M. Ahmed Abdel Meneim, Zeid S.A (2013): Geoelectric sounding to delineate the Quaternary Aquifer in the Central Part of Wadi Qena, Eastern Desert, Egypt. Journal, Applied. Geophysics. Vol. 12 No. 2 Sep. 2013 pp. 191-207
• Sewwandi, BGNVithanage, Meththika W., SSRMDHRMowjood, MIMHamamoto, Shoichiro
• Kawamoto, Ken.(2014): Adsorption of Cd (II) and Pb (II) onto Humic Acid–Treated Coconut (Cocosnucifera) Husk, Journal of Hazardous, Toxic, and Radioactive Waste ,vol. 18, (2) pp. 04014001
• Treacy, Higgins MMJ, JB. (2001): Collection of simulated XRD powder patterns for zeolites. Published on behalf of the Structure Commission of the ‘International Zeolite Association’, journal Powder Patterns, vol.203, pp. 204
• Thyfault and Mackayla J.( 2016): Removal of iron, zinc, and copper from waters impacted by acid mine drainage using natural zeolite. Publisher the University of Texas at El Paso.
• Wang, Haiyan T., Elizabeth A H., Yining(2006): Investigations of the adsorption of n-pentane in several representative zeolitesjournal of Physical Chemistry B,vol.110( 16),pp. 8240-8249
• Wei, Ta-Chenn H., Hugh W.(2006): Ion transport in the microporous titanosilicate ETS-10, journal The Journal of Physical Chemistry B,vol. 110(28),pp 13728-13733
• Zhao, Difang Zhou, Jie Liu, Ning (2006): Preparation and characterization of Mingguangpalygorskite supported with silver and copper for antibacterial behavior. Journal Applied Clay Science , 33 (3): 161-170.
• Qin, FeiWen, BeiShan, Xiao-QuanXie, Ya-NingLiu, TaoZhang, Shu-ZhenKhan, Shahamat U (2006): Mechanisms of

competitive adsorption of Pb, Cu, and Cd on peat ,Journal  Environmental Pollution ,vol. 144 , (2) , pp. 669-680

• Ünlü, Nuriersoz, Mustafa (2006): Adsorption characteristics of heavy metal ions onto a low cost biopolymeric sorbent from aqueous solutions ,Journal of Hazard Mater, vol. 136  , (2) , pp. 272-280