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International Journal of Environment, Ecology, Family and Urban Studies (IJEEFUS) ISSN 2250-0065 Vol. 3, Issue 4, Oct 2013, 9-22 © TJPRC Pvt. Ltd.

POTENTIAL OF MORINGA OLEIFERA (DRUM STICKS) SEEDS AND ITS APPLICATION AS NATURAL ADSORBENT IN REMOVAL OF HEAVY METAL IONS DESAI B1 & DESAI H2 TIFAC Center of Relevance and Excellence in Environmental Engineering and Science, Sarvajanik College of Engineering and Technology, Surat, Gujarat, India

ABSTRACT The removal of heavy metals (Copper, Zinc and Iron) from ground water (Udhna Gam) sample was done by using the natural adsorbent Moringa oleifera seed powder (MOSP). The variables for pH were decided at pH 4, 6, 7, 8 and 10 to find out optimum pH for further treatment. The variables for contact time were decided as ½ hour, 1 hour, 1.5 hours, 2 hours and 2.5 hours to find out optimum contact time for further treatment. The pH 8.7 and 2.5 hours contact time were considered as optimum pH and optimum contact time respectively because maximum %removal efficiency of water pollutants was observed at pH 8.7 and at 2.5 hours contact time. The variables for MOSP dosage were decided as 2000 ppm, 3000 ppm, 4000 ppm, 5000 ppm and 6000 ppm to find out optimum MOSP dosage to get maximum % removal efficiency of heavy metals from the Udhna Gam ground water sample. The MOSP dosage of 6000 ppm (6 g/l) had established good chemistry with drinking water Indian standard. Maximum reduction of Copper (99.94%), Zinc (95.38 %) and Iron (96 %) was observed at pH 8.7, 2.5 hour contact time and at 6000 ppm MOSP dosage.

KEYWORDS: Moringa oleifera Seed Powder (MOSP), Udhna Gam Ground Water Sample INTRODUCTION Presently there are no appropriate low-cost technologies available for removal of several commonly present groundwater contaminants and the typical conventional water treatment are highly costly and higher amount of chemical sludge is generated which poses disposal problem. Chemical coagulants like Aluminium Sulphate (alum), FeCl 2 are used in this conventional drinking water treatment for purification process. But excess use of these chemical coagulants can affect human health e.g. Alum has been indicated to be a causative agent in neurological diseases such as pre-senile dementia and also found to be carcinogenic. To overcome above described problem of chemical coagulant problem, it is necessary to increase the use of natural coagulants for drinking water treatment. Naturally occurring coagulants are usually presumed safe for human health. Some studies on natural coagulants have been carried out and various natural coagulants were produced or extracted from microorganisms, animals or plants. One of these alternatives is Moringa oleifera seeds (MOSP). It is a native tree of the sub-Himalayan parts of North-west India, Pakistan and Afghanistan and can grow anywhere. Moringa oleifera is a perfect example of “multipurpose tree”. 1 Among all the plant materials that have been tested over the years, powder processed from the seeds of Moringa oleifera has been shown to be one of the most effective for water treatment. Earlier studies have found MOSP to be nontoxic 2, and recommended it to use as a coagulant in developing countries. According to Muyibi and Evison, 1994,

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Hardness removal efficiency of MOSP was found to increase with increasing dosage. The active ingredients are dimeric proteins. The protein powder is stable and totally soluble in water. The coagulation mechanism of the M. oleifera coagulant


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Desai B & Desai H

protein has been explained in different ways. It has been described as adsorption and charge neutralization and interparticle bridging. Flocculation by inter-particle bridging is main characteristic of high molecular weight cationic and anionic Polyelectrolytes. Apart from all these, the objectives of this research work are:To develop the best and eco friendly, cost effective water treatment technology for purifying groundwater to make it drinking water, to investigate adsorption behavior of water pollutants on to Moringa oleifera seed powder, to evaluate the optimum dosage of Moringa oleifera seed powder and its removal efficiency for seleced water quality parameters, to check the suitability of Udhna Gam ground water for various purposes like drinking, domestic, etc. before and after treatment with Moringa oleifera seed powder.

METHODOLOGY Sampling and preservation of ground water sample was done as per Water Analysis Handbook by HACH.

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Ground water from bore well near Udhna Gam, Surat was taken for treatment with Moringa oleifera seed powder (MOSP). Experimental Set up to Study Effects of pH, Contact Time and Dosage of MOSP on Adsorption of Water Pollutants Such 5 sets of 2000 ml beaker containing 1000 ml of ground water sample of Udhna Gam were prepared. pH in each beaker was varied as 4, 6, 7, 8, 10 by adding required amount of 1 N H2SO4 and 1 N NaOH. 2000 ppm MOSP in each beaker was added the system was kept in jar test apparatus at 120 rpm for 3-5 minutes and at 50 rpm for 30 minutes to determine optimum pH for adsorption of water pollutants by MOSP. After 30 minutes the samples from each beaker was filtered by using whatmen filter paper 42 and then check the concentration of heavy metals (Copper, Zinc, Iron) after giving a treatment with MOSP. pH in each beaker was varied from 4-4.2, 6-6.4, 7-7.8, 8-8.7, 10-10.3 after adding 2000 ppm MOSP and after jar test experimental work. 5 In all sets pH was found increased. From these results it is confirmed that MOSP makes water alkaline. The maximum reduction of Heavy metals was observed at pH 8. At pH 8 and at 2000 ppm dosage of MOSP, the system (above described 5 beaker sets) was kept in jar test apparatus for 30 minutes, 1 hour, 1.5 hours, 2 hours, and 2.5 hours to determine optimum contact time. The maximum reduction of Heavy metals was observed at 2.5 hours contact time. The Dosage of MOSP i.e. 2000 ppm, 3000 ppm, 4000 ppm, 5000 ppm, 6000 ppm were selected for treatment of ground water and this dosage were added respectively into the five beakers containing 1 liter of ground water sample and the system was kept in jar test apparatus and 120 rpm was set for first 3-5 minutes and then 50 rpm was set (to prevent oil separation from MOSP) and run it for 2.5 hours at pH 8. After each experimental work the concentration of heavy metals were determined as per Standard Methods for the Examination of Water and Waste water (standard APHA method).

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Batch Isotherm Studies Isotherm experiments were conducted to investigate the relationship between the solid phase concentration of an adsorbate and the solution phase concentration of the adsorbate at an equilibrium condition. The removal percentage (R %) of various parameters was calculated for each run by following equation: R (%) = [(Ci-Ce)/Ci]Ă—100 Where, Ci and Ce were the initial & final concentration (mg/l) in the solution. The adsorption capacity (mg/g) was calculated using following equation: qe (mg/g) = [(Ci-Ce)/M]Ă—V Where, Ci and Ce were the initial & final concentration of water quality parameters (mg/l) in the test solution respectively. V is the volume of solution (in Liter) & M is the mass of adsorbent (gm). Calculation for various isotherms has shown in table: 1. 6


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Potential of Moringa oleifera (Drum Sticks) Seeds and its Application as Natural Adsorbent in Removal of Heavy Metal Ions

Table 1: Calculation for Various Isotherms Langmuir Isotherm

Freundlich isotherm Temkin isotherm BET isotherm

Ce→ce Q0= 1 qe Slope Ce/qe= [1/Q0b +1/Q0×Ce] n= 1 LogCe→ Log qe slope Log10qe = log10(Kf) + (1/n)log10(Ce) LnCe→qe b=Slope X= a+blnC c e→ c e Slope=B-1 ci (ci-ce*qe) B*qmax Cf/[(Cf-Cs)]= 1/Bqmax + (B-1/Bqmax) (Cf/Cs)

b= Intercept*Q0

Kf=Antilog(intercept) a=Intercept 1 = intercept B*qmqx

RESULTS AND DISCUSSIONS The concentration of heavy metals after treatment with MOSP at different pH and at ½ hour contact time are given in table: 1. Table 2: Parameters Studied before and after Treatment of Udhna Gam Ground Water at MOSP Dosage of 2 g/l and ½ Hour Contact Time at Different pH After Treatment at Various pH

Sr. No.

Parameters

Before Treatment

pH 4

pH 6

pH7

pH 8

pH 10

1. 2. 3.

Copper Zinc Iron

95.31 195 0.25

47.66 100 0.22

41.3 95 0.2

41.3 93 0.13

38.12 83 0.092

41.1 86.8 0.095

IS 10500 Drinking Water 0.05 10 0.3

%Removal Efficiency at pH 8 60.004 57.43 63.2

Effect of pH on Reduction of Heavy Metals Graphical representation for Heavy metals (Copper, Zinc and Iron) of Udhna Gam ground water sample before and after treatment with MOSP at different pH is given in figure 1, figure 2, figure 3 respectively. The initial Heavy metal ions (Copper, Zinc and Iron) concentration observed were 95.31 mg/l and 195 mg/l 0.25 mg/l respectively in ground water sample of Udhna Gam which were above the desirable limits of Drinking Water IS 10500. After treatment with MOSP, at different pH, the maximum reduction of Copper, Zinc, Iron concentration was found at pH 8.7 that is 38.12 mg/l, 86 mg/l, 0.092 mg/l respectively. The minimum adsorption observed at low pH may be due to the fact that the higher concentration and higher mobility of H + ions present, favored the preferential adsorption of Hydrogen ions compared to metals ions on adsorbent. At low pH value, the surface of the adsorbent is surrounded by hydronium ions (H 3O+) thereby preventing the metal ions from approaching the binding sites of sorbent. This means that at higher H+ concentration, the surface becomes more positively charged. Thus reducing attraction between adsorbents and metal ions. At higher pH the adsorbent surface takes more negative charges, thus attracting more metal ions. However it was also observed that the adsorption capacity of metal ions decreased with further increases in pH due to the formation of anionic hydroxide which reduced the adsorption of free metal ions [metal hydroxide precipitate formation]. So optimum pH for removal of heavy metal is pH 8.7. 7, 8


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Figure 1: Graphical Representation for Copper of Udhna Gam Ground Water Sample at Different pH and at 1/2 Hour Contact Time and 2000 ppm Dosage of MOSP

Figure 2: Graphical Representation for Zinc of Udhna Gam Ground Water Sample at Different pH and at 1/2 Hour Contact Time and 2000 ppm Dosage of MOSP

Figure 3: Graphical Representation for Iron of Udhna Gam Ground Water Sample at Different pH and at 1/2 Hour Contact Time and 2000 ppm Dosage of MOSP Contact Time Variation The concentration of heavy metals after treatment with MOSP at pH 8.7, at 2000 ppm MOSP dosage and at different contact time are given in table: 3. Table 3: Parameters Studied before and after Treatment of Udhna Gam Ground Water at MOSP Dosage of 2 g/l at pH 8.7 and at Different Contact Time Sr. No.

Parameters

Before Treatment

1. 2. 3.

Copper Zinc Iron

95.31 195 0.25

After Treatment at Various Contact Time 1/2 1 1.5 2 2.5 Hour Hour Hours Hours Hours 38.15 32.12 25.74 22.95 15.2 83 79 70 69.9 69.8 0.092 0.062 0.05 0.049 0.04

IS 10500 Drinking Water

%Removal Efficiency at 2.5 hours contact time

0.05 10 0.3

84.05 64.2 84


Potential of Moringa oleifera (Drum Sticks) Seeds and its Application as Natural Adsorbent in Removal of Heavy Metal Ions

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Effect of Contact Time on Reduction of Copper, Zinc, Iron The removal of water pollutants from ground water sample is highly dependent on contact time of the sample with MOSP. This is attributed to the fact that the increase of contact time improves the diffusion of water pollutants towards the surface of adsorbents. Increasing contact time reduces the film boundary layer surrounding the adsorbent particles thus increasing the external film mass transfer coefficient and the rate of water pollutant adsorption. From the experiment, it has been concluded that 2.5 hours contact time of the ground water with MOSP was considered as optimum time for further experiments. 6 .Effect of contact time on reduction of Copper, Zinc, Iron, are shown in figure 4, 5, 6.

Figure 4: Graphical Representation for Copper of Udhna Gam Ground Water Sample at Different Contact Time at Optimum pH 8.7 and at 2000 ppm Dosage of MOSP

Figure 5: Graphical Representation for Zinc of Udhna Gam Ground Water Sample at Different Contact Time at Optimum pH 8.7 and at 2000 ppm Dosage of MOSP

Figure 6: Graphical Representation for Iron of Udhna Gam Ground Water Sample at Different Contact Time at Optimum pH 8.7 and at 2000 ppm Dosage of MOSP Dosage Variation The results of water quality parameters at different dosage of MOSP at pH 8.7 and at 2.5 hours contact time are given in table: 4.


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Table 4: Parameters Studied before and after Treatment of Udhna Gam Ground Water at Different Dosage of MOSP at pH 8.7 and at 2.5 Hours Contact Time Sr. No.

Parameters

Before Treatment

1. 2. 3.

Copper Zinc Iron

95.31 195 0.25

After treatment with Various Dosage of MOSP 2000 3000 4000 5000 6000 ppm ppm ppm ppm ppm 15.3 7.5 0.92 0.22 0.054 69.7 52 32.5 20 9 0.04 0.039 0.02 0.01 0.01

IS 10500 Drinking Water

%Removal Efficiency at 6000 Dosage of MOSP

0.05 10 0.3

99.94 95.38 96

Effect of MOSP Dosage on Reduction of Heavy Metals (Copper, Zinc and Iron) Graphical representation for heavy metal ions (Copper, Zinc and Iron) of Udhna Gam ground water sample before and after treatment with MOSP is given in figure7, figure 8 and figure 9 respectively. The initial Heavy metal ions (Copper, Zinc and Iron) was found above desirable limit of Drinking Water IS 10500 i.e. 95.31 mg/l and 195 mg/l and 0.25 mg/l, respectively, After treatment with MOSP, the Copper, Zinc and Iron was found 0.054 mg/l, 9.0 mg/l. and 0.01 mg/l respectively which were below desirable limit of Drinking Water IS 10500 and showed decrease in amount of Heavy metals of ground water with increased dose of MOSP. The adsorption of metals using Moringa is limited to the adsorption surface. This is because Moringa is a polyelectrolyte of short chain and low molecular weight. Heavy metals and solids that have high charges than Moringa colloidal surface will remove high percentage of metals compared to other seeds. The mechanism that brings about the adsorption of heavy metals is through the positive metal ion that forms a bridge among the anionic polyelectrolyte and negatively charged protein functional groups on the colloidal particle surface. There is formation of complexes with the heavy metals and the organic matter of Moringa and other seeds such as proteins. Due to its hydrophilic character, several hydrogen bonds are formed among polyelectrolyte and water molecules. Polyelectrolyte coagulant aids have structures consisting of repeating units of small molecular weight forming molecules of colloidal size that carry electrical charges or ionisable groups that provide bonding surfaces for the flocs. Adsorption describes attachment of ions and molecules from seed protein by means of specific mechanisms. Further research on this could help determine the mechanisms of the reaction. However, adsorption is one of the processes affecting speciation, migration and biological availability of trace elements in natural water. Metal ions in coagulation react with proteins and destroy them in water. Metal adsorption occurs due to the high protein content of the seeds except for corn where starch is one of the non-ionic polymers that aid the adsorption. 7, 8

Figure 7: Graphical Representation for Copper of Udhna Gam Ground Water Sample before and after Treatment with MOSP at pH 8.7 and 2.5 Hour Contact Time


Potential of Moringa oleifera (Drum Sticks) Seeds and its Application as Natural Adsorbent in Removal of Heavy Metal Ions

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Figure 8: Graphical Representation for Zinc of Udhna Gam Ground Water before and after Treatment with MOSP at pH 8.7 and 2.5 Hour Contact Time

Figure 9: Graphical Representation for Iron of Udhna Gam Ground Water Sample before and after Treatment with MOSP at pH 8.7 and 2.5 Hour Contact Time % Removal Efficiency of Heavy Metals at pH 8.7, at 2.5 Hour Contact Time and at 6000 ppm Dosage of MOSP % Removal Efficiency of Heavy Metals at pH 8.7, at 2.5 hour contact time and at 6000 ppm Dosage of MOSP is graphically represented in figure: 10. Maximum reduction of Copper (60.004%), Zinc (57.43 %) and Iron (63.2 %) was observed at pH 8.7. Maximum reduction of Copper (84.05%), Zinc (64.2 %) and Iron (84 %) was observed at 2.5 hour contact time. Maximum reduction of Copper (99.94%), Zinc (95.38 %) and Iron (96 %) was observed at 6000 ppm MOSP dosage. So, pH 8.7, 2.5 hour contact time and 6000 ppm MOSP dosage was obtained as optimum condition for heavy metal removal from the Udhna Gam ground water sample.

Figure 10: % Removal Efficiency of Heavy Metals at pH 8.7, at 2.5 Hour Contact Time and at 6000 ppm Dosage of MOSP


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Adsorption Isotherm Studies for Heavy Metals Removal Langmuir and BET Isotherms for Copper Graphical representation for Langmuir and BET isotherms for Copper is shown in figure 11 and figure 12. Various Equilibrium Parameters for Langmuir and BET isotherms for Copper are given in following table 5. Table 5: Various Equilibrium Parameters for Langmuir and BET Isotherms for Copper Adsorbent Dosage (g) 2 3 4 5 6

Langmuir Isotherm Ce qe 15.3 40.005 7.5 29.28 0.92 23.59 0.22 19.01 0.054 15.8

BET Isotherm

Ce / qe 0.38 .25 0.038 0.011 0.00342

Cf 15.3 7.5 0.92 0.22 0.054

Figure 11: Langmuir Isotherm for Copper

q 40.005 29.28 23.59 19.01 15.8

Cf / Cs 0.1605 0.6786 0.00965 0.60230 0.0005665

Cf /(Cs- Cf)Ă—q 0.0047 0.0029 0.00041 0.00013 0.000035

Figure 12: BET Isotherm for Copper

Table 6: Langmuir and BET Isotherms Constants for Copper Parameters Copper

Langmuir Isotherm R2 Q0(mg/g) b(l/mg) 0.975 39.52 1.66

R2 0.985

BET Isotherm qmax(mg/g) B(l/mg) 34.48 infinity

For Langmuir isotherm R2 value is 0.975 which indicates that Copper removal by Moringa oleifera seed powder (MOSP) follows the Langmuir isotherm. The Q0 (mg/g) value is 39.52 shows high adsorption capacity and b (l/mg) value is 1.66 suggest lower rate of adsorption. 9 For BET isotherm the R2 value is 0.985 which indicates that Copper removal by MOSP follows BET isotherm. The value of qmax (mg/g) is 34.48 and B (l/mg) value is infinity indicating the adsorption rate of Copper on MOSP. Langmuir and BET Isotherms for Zinc Graphical representation for Langmuir and BET isotherms for Zinc is shown in figure 13 and figure 14. Various Equilibrium Parameters for Langmuir and BET isotherms for Zinc are given in following table 7. Table 7: Various Equilibrium Parameters for Langmuir and BET Isotherms for Zinc Adsorbent Dosage (g) 2 3 4 5 6

Langmuir Isotherm Ce qe 69.70 62.65 52 47.66 32.5 40.6 20 35 9 31

Ce / qe 1.11 1.69 0.80 0.57 0.29

Cf 69.70 52 32.5 20 9

BET Isotherm q Cf / Cs Cf /(Cs- Cf)Ă—q 62.65 0.3574 0.0088 47.66 0.2666 0.0076 40.6 0.1666 0.0049 35 0.1025 0.0032 31 0.0461 0.0015


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Potential of Moringa oleifera (Drum Sticks) Seeds and its Application as Natural Adsorbent in Removal of Heavy Metal Ions

Figure 13: Langmuir Isotherm for Zinc

Figure 14: BET Isotherm for Zinc

Table 8: Langmuir and BET Isotherms Constants for Zinc Parameters

Langmuir Isotherm R Q0(mg/g) b(l/mg) 0.911 72.99 0.0505 2

Zinc

BET Isotherm R qmax(mg/g) B(l/mg) 0.978 41.66 infinity 2

For Langmuir isotherm R2 value is 0.911 which indicates that Zinc removal by Moringa oleifera seed powder (MOSP) follows the Langmuir isotherm. The Q0 (mg/g) value is 72.99 suggest high adsorption capacity and b (l/mg) value is 0.0505 suggest lower rate of adsorption.

9, 10

For BET isotherm the R2 value is 0.978 which indicates that Zinc removal

by MOSP follows BET isotherm. The value of q max (mg/g) is 41.66 suggest high adsorption capacity and B (l/mg) value is infinity indicating the adsorption rate of Zinc on MOSP. Langmuir and BET Isotherms for Iron Graphical representation for Langmuir and BET isotherms for Iron is shown in figure 15 and figure 16. Various Equilibrium Parameters for Langmuir and BET isotherms for Iron are given in following table 9. Table 9: Various Equilibrium Parameters for Langmuir and BET Isotherms for Iron Adsorbent Dosage (g) 2 3 4 5 6

Langmuir Isotherm Ce qe 0.04 0.105 0.039 0.07 0.02 0.05 0.01 0.048 0.01 0.04

BET Isotherm

Ce / qe 0.38 0.55 0.4 0.2 0.2

Figure 15: Langmuir Isotherm for Iron

Cf 0.04 0.039 0.02 0.01 0.01

q 0.105 0.07 0.05 0.048 0.04

Cf / C s 0.16 0.156 0.084 0.04 0.04

Cf /(Cs- Cf)Ă—q 0.1904 0.1848 0.0917 0.041 0.041

Figure 16 BET Isotherm for Iron


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Table 10: Langmuir and BET Isotherms Constants for Iron Parameters Iron

Langmuir Isotherm R2 Q0(mg/g) b(l/mg) 0.712 0.1188 57.69

R2 0.999

BET Isotherm qmax(mg/g) B(l/mg) 0.8090 -128.1

For Langmuir isotherm R2 value is 0.712 which indicates that Iron removal by Moringa oleifera seed powder (MOSP) follows the Langmuir isotherm. The Q0 (mg/g) value is 0.1188 suggest low adsorption capacity and b (l/mg) value is 57.69 suggest higher rate of adsorption. For BET isotherm the R2 value is 0.999 which indicates that Iron removal by MOSP follows BET isotherm. The value of q max (mg/g) is 0.8090 suggest low adsorption capacity. B (l/mg) value is -28.1. This indicates the inadequacy of the BET isotherm model to explain the adsorption process. Thus adsorption of Iron can be very well described and fitted by Langmuir isotherm. 11 Langmuir and BET Isotherms Constant Langmuir and BET isotherms constant R2, Q0(mg/g), b(l/mg), qmax(mg/g) and B(l/mg) are given in table 11. Table 11: Langmuir and BET Isotherms Constants for all Parameters which follow Langmuir and BET Isotherms Parameters Copper Zinc Iron

Langmuir Isotherm R2 Q0(mg/g) b(l/mg) 0.979 39.52 1.66 0.911 72.99 0.05 0.712 0.1188 57.69

R2 0.985 0.978 0.999

BET Isotherm qmax(mg/g) B(/l/mg) 34.48 infinity 41.66 infinity 1.25 -128.1

For above cited Langmuir and BET adsorption isotherms, the value of R2 (correlation coefficient) is found in the range of 0.712-0.999, indicates favorable adsorption and follow Langmuir and BET adsorption isotherms. Higher the value of adsorption capacity i.e. Q0(mg/g), qmax(mg/g) suggests greater amount of adsorption capacity of adsorbent. Copper, Zinc having high Q0(mg/g), qmax(mg/g) values suggests greater amount of adsorption capacity of adsorbent. Higher the value i.e. b(mg/l), and B(mg/l) shows the fastest rate of adsorption. Iron having high b (mg/l) values suggest fastest rate of adsorption. Higher adsorption capacity always follow slower rate of adsorption. While lower adsorption capacity is observed with higher rate of adsorption. 12 Here, all the above listed parameters Copper, Zinc Iron, Which follow Langmuir Isotherm indicates monolayer adsorption also follow BET isotherm, indicates that the same adsorbate is adsorbed in multilayer fashion on the adsorbent. 5 Freundlich and Temkin Isotherms for Copper Graphical representation for Freundlich and Temkin isotherms for Copper is shown in figure 17 and figure 18. Various Equilibrium Parameters for Freundlich and Temkin isotherms for Copper are given in following table 12. Table 12: Various Equilibrium Parameters for Freundlich and Temkin Isotherms for Copper Adsorbent Dosage (g) 2 3 4 5 6

Ce 15.3 7.5 0.92 0.02 0.054

Freundlich Isotherm qe log Ce 40.005 1.1846 29.28 0.8750 23.59 -0.0362 19.01 -1.6989 15.8 -1.2676

log qe 1.6021 1.4665 1.3727 1.2785 1.1986

C 15.3 7.5 0.92 0.22 0.054

Temkin Isotherm ln c x 40.005 2.7278 29.28 2.0149 23.59 -0.0833 19.01 2.9449 15.8 2.7600


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Potential of Moringa oleifera (Drum Sticks) Seeds and its Application as Natural Adsorbent in Removal of Heavy Metal Ions

Figure 17: Freundlich Isotherm for Copper

Figure 18: Temkin Isotherm for Copper

Table 13: Freundlich and Temkin Isotherms constants for Copper Parameters Copper

Freundlich Isotherm R2 Kf(mg/g) n(l/mg) 0.854 25.4431 8.7108

Temkin Isotherm R2 a(mg/g) b(l/mg) 0.0005 25.18 0.17

For Freundlich isotherm R2 value is 0.854 which indicates that Copper removal by MOSP follows Freundlich isotherm. The value of Kf (mg/g) is 25.4431 shows high adsorption capacity and n (l/mg) is 8.7108 shows high adsorption intensity. For Temkin isotherm R2 value is 0.0005 which indicates that Copper removal by MOSP do not follow Temkin isotherm. The value of a (mg/g) is 25.18 and b (l/mg) value is 0.17. Freundlich and Temkin Isotherms for Zinc Graphical representation for Freundlich and Temkin isotherms for Zinc is shown in figure 19 and figure 20. Various Equilibrium Parameters for Freundlich and Temkin isotherms for Zinc are given in following table 14. Table 14: Various Equilibrium Parameters for Freundlich and Temkin Isotherms for Zinc Adsorbent Dosage (g) 2 3 4 5 6

Ce 69.7 52 32.5 20 9

Freundlich Isotherm qe log Ce log qe 62.65 1.8432 1.7969 47.66 1.7160 1.6781 40.6 1.5118 1.6085 35 1.3010 1.5443 31 0.9542 1.4973

Figure 19: Freundlich Isotherm for Zinc

C 69.7 52 32.5 20 9

Temkin Isotherm ln c x 4.2442 62.65 3.9512 47.66 3.4812 40.6 2.9957 35 2.1972 31

Figure 20: Temkin Isotherm for Zinc


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Table 15: Freundlich and Temkin Isotherms Constant for Zinc Parameters R2 0.884

Zinc

Freundlich Isotherm Kf(mg/g) n(l/mg) 25.4331 3.1776

R2 0.824

Temkin Isotherm a(mg/g) b(l/mg) -3.675 13.97

For Freundlich isotherm R2 value is 0.884 which indicates that Zinc removal by MOSP follows Freundlich isotherm. The value of Kf (mg/g) is 25.4331 shows high adsorption capacity and n (l/mg) is 3.1776 shows high adsorption intensity. For Temkin isotherm R2 value is 0.824 which indicates that Zinc removal by MOSP follows Temkin isotherm. b (l/mg) value is 13.97 shows high adsorption intensity. Freundlich and Temkin Isotherms Constant Freundlich and Temkin isotherms constant R2, Kf(mg/g) n(l/mg), a(mg/g) and b(l/mg) are given in table 16. Table 16: Freundlich and Temkin Isotherms Constants which follow Freundlich and Temkin Isotherms Parameters Copper Zinc

Freundlich Isotherm R2 Kf(mg/g) n(l/mg) 0.854 25.44 8.7 0.884 25.43 3.17

Temkin Isotherm R2 a(mg/g) b(l/mg) 0.000 25.18 0.17 0.824 3.67 13.97

For above cited all adsorption isotherms (table 5.6.12), the value of R 2 (correlation coefficient) is found in the range of 0.000-0.884, indicates favorable adsorption and follow Freundlich and Temkin adsorption isotherms. Higher the value of adsorption capacity i.e. Kf (mg/g), a (mg/g) suggests greater amount of adsorption capacity of adsorbent. Copper, Zinc having high Kf (mg/g) values and Copper and Zinc having high a(mg/g) values suggests greater adsorption capacity of adsorbent for these adsorbate (parameters). Higher the value i.e n (l/mg), and b (l/mg) shows the higher adsorption intensity. Copper, Zinc having high b (l/mg) values suggest the higher adsorption intensity. Higher adsorption capacity always follow slower rate of adsorption.

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While lower adsorption capacity is

observed with higher rate of adsorption. Here, above listed parameters Copper, Zinc Which follow Freundlich isotherm assumes that the uptake of water pollutants occur on a heterogeneous surface by multilayer adsorption.

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The Temkin

isotherm assumes that the heat of adsorption of all the molecules in layer decreases linearly with coverage due to adsorbent-adsorbate interactions and that the adsorption is characterized by a uniform distribution of the bonding energies, up to some maximum binding energy (Temkin, 1940).

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Zinc is having high R2, a (mg/g) and b(mg/l) values suggest Zinc

also follows Temkin Isotherm.

CONCLUSIONS From the experimental data shown in above table 5.9, it has been concluded that 6000 ppm dosage of MOSP was considered as the optimum dosage for heavy metal removal. After addition of MOSP the sample pH came into the alkaline range which is beneficial to the human health as it has been proved as an anti carcinogenic and anti acidic. After treatment with MOSP, % Removal Efficiency of heavy metals at 6000 ppm dosage of MOSP were obtained: Copper (99.94%), Zinc (95.38%), Iron (96%). Copper and Zinc follow Landmuir, BET and Freundlich isotherms. Copper does not follow Temkin isotherm. Iron follow Langmuir and BET isotherm but does not follow Freundlich and Temkin isotherm. From all the experiments carried out in the study it is concluded that Moringa oleifera is found natural phytoremedy for Ground Water Treatment. Ground Water Treatment by Moringa oleifera seed powder as an adsorbent is ecofriendly, economic and energy efficient water technology best suitable for people living in rural area and polluted area where water quality is not up to the expectation from health point of view.


Potential of Moringa oleifera (Drum Sticks) Seeds and its Application as Natural Adsorbent in Removal of Heavy Metal Ions

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REFERENCES 1.

Price Dr. M. L., The Moringa Tree, Echo Technical Note, (1985).

2.

Suleyman A. Muyibi S.A. and Evison L.M., Moringan oleifera seeds for softening hard water, Wat. Res., 29(4), 1099-1105,(1994).

3.

Mangale S. M., Chonde S. G., Jadhav A. S., and Raut P. D., Study of Moringa oleifera (Drumstick) seed as natural Absorbent and Antimicrobial agent for River water treatment, J. Nat. Prod. Plant Resour., 2 (1), 89-100, (2012).

4.

Water Analysis Handbook by HACH, 4th Edition ,(2003).

5.

Patel N., Desai H., Potential of Moringa oleifera Seeds,Leaves and Bark for Removal of Hexavalent Chromium from Aqueous Solution with Reference to the Adsorption Isotherm, International Journal of Water Resources and Environmental Management, 2(1), 41-57, (2011).

6.

Andrew D eaton, Lenore S. Clesceri, Eugene W. Rice Arnold E. Greenberg, Standard Methods for the Examination of Water and Waste water, 21st Edition, (2005).

7.

Sajidu1 S. M. I., Persson I., Masamba W. R. L. and Henry E. M. T., Mechanisms for biosorption of chromium(III), copper(II) and mercury(II) using water extracts of Moringa oleifera seed powder, African Journal of Biotechnology , 7 (6), 800-804, (2008).

8.

Nand V., Maata M., Koshy K., Sotheeswaran S., Water Purification using Moringa oleifera and Other Locally Available Seeds in Fiji for Heavy Metal Removal, International Journal of Applied Science and Technology, 2 (5), ( 2012).

9.

L. M. Mataka, S. M. I. Sajidu, W. R. L. Masamba and J. F. Mwatseteza, Cadmium sorption by Moringa stenopetala and Moringa oleifera seed powders: Batch, time, temperature, pH and adsorption isotherm studies, International Journal of Water Resources and Environmental Engineering, 2 (3), 50–59, (2010).

10. Argun M.E., Dursun S., Ozdemir C., Karatas M., Heavy metals Adsorption by Modified Oak Sawdust: Thermodyanamics and Kinetics, Journal of Hazardous Material, 141(1), 77-85, (2006). 11. Ho Y.S. and McKay G., The Kinetics of Sorption of Divalent Metal Ions Into Sphagnum Moss Peat, Water Resources, 34, 735-742, (2000). 12. Clair N. Sawyer, Perry L. MacCarty, Gene F. Parkin, Chemistry for Environmental Engineering and Science, 5 th Edition, (2005). 13. Hu j, Chen G. and Irene M.C., Lo., Removal and Recovery of Chromium Hexavallent from Waste Water by Maghnemite Nanoparticles, Water Research, 39(18), 4528-4536, (2005). 14. Oladoja N. A., Aboluwoye C. O., Oladimeji Y. B., Kinetics and Isotherm Studies on Methylene Blue Adsorption onto Ground Palm Kernel Coat, Turkish Journal of Environmental Engineering and Science, 32, 303-312, (2008).


2 env eco ijeefus potential of moringa desai paid  

The removal of heavy metals (Copper, Zinc and Iron) from ground water (Udhna Gam) sample was done by using the natural adsorbent Moringa ole...

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