A batch adsorption study was carried out to investigate the adsorption of lead (II) ions on the blend of activated carbon and chitosan from the mussel shell of the lead water solution. The optimum chitosan/activated carbon blend dosage was 5 g (2.5 g activated carbon and 2.5 g chitosan). At optimum dosage, the percentage uptake was 83.75%, and 0.134 mg/l of Pb2+ was removed, while at an equilibrium contact time of 120 minutes, the percentage uptake was 98.75%. The data generated was used for isotherm studies and kinetic modelling. The Langmuir isotherm fits best with an R2 value of 0.9776, and the adsorption was favourable at 0.0842 kJ/mol. Also, the adsorption process follows the Pseudo second-order kinetic model with an R2 value of 0.9981

Adamu, Hashim

Dokas, Kish Elisha

Mamman, Mohammed Yusuf

Olayinka, Akorede Abdulafeez

Yusuf, Abdulwadud Abdulkarim

English

Traektoria Nauki

Path of Science. 2024. Vol. 10. No 9   ISSN 2413-9009 Section “Engineering, Manufacturing, and Construction”    3001 Adsorption Study of Pb (II) Ion Removal From Lead Solution Using a Blend of Activated Carbon and Chitosan From Mussel Shells  Abdulkarim Abdulwadud Yusuf 1, Adamu Hashim 2, Kish Elisha Dokas 2,  Akorede Abdulafeez Olayinka 2, Mohammed Yusuf Mamman 2  1 Abubakar Tafawa Balewa University Dass road, P. M. B. 0248, Bauchi, 740272, Nigeria 2 Air Force Institute of Technology, Kaduna P. M. B. 2104, Kaduna, Nigeria  DOI: 10.22178/pos.108-3  LCC Subject Category: T1-995  Received 26.08.2024 Accepted 28.09.2024 Published online 30.09.2024  Corresponding Author: Abdulkarim Abdulwadud Yusuf aabdulwadud@atbu.edu.ng  © 2024 The Authors. This article is licensed under a Creative Commons Attribution 4.0 License   Abstract. A batch adsorption study was carried out to investigate the adsorption of lead (II) ions on the blend of activated carbon and chitosan from the mussel shell of the lead water solution. The optimum chitosan/activated carbon blend dosage was 5 g (2.5 g activated carbon and 2.5 g chitosan). At optimum dosage, the percentage uptake was 83.75%, and 0.134 mg/l of Pb2+ was removed, while at an equilibrium contact time of 120 minutes, the percentage uptake was 98.75%. The data generated was used for isotherm studies and kinetic modelling. The Langmuir isotherm fits best with an R2 value of 0.9776, and the adsorption was favourable at 0.0842 kJ/mol. Also, the adsorption process follows the Pseudo second-order kinetic model with an R2 value of 0.9981. Keywords: Isotherm; Kinetics; Activated-Carbon Chitosan; Mussel; Lead; Adsorption.   INTRODUCTION Heavy metals in wastewater significantly threat-en the quality of portable drinking water. An ex-ample of such heavy metals is lead, which is high-ly soluble in water, and some lead salts have a solubility of about 10 g/l [1]. The World Health Organization standard for the maximum amount of safe drinking water is 10 µg/l [2]. Any water with dissolved lead ions more than the above-stated value can be said to be unsafe for human consumption and could have lethal effects if in-gested into the human body [3]. Chitosan has been widely used in vastly diverse fields, from waste management to food pro-cessing, medicine and biotechnology [4]. In agri-culture, chitosan has been established to improve the yield of rice and orchid production [5]. A lot of work has been done on kinetics concerning chitosan and adsorption. The equilibrium and kinetic studies on the adsorption of metallic ions onto chitosan were carried out. Kinetics and equilibrium studies adsorption of Cu(II) and Cr(VI) ions by Chitosan [6]. Studies on the re-moval of Cr(VI) and Cu(II) ions using Chitosan-grafted-polyacrylonitrile [7]. Recent work was conducted on the Kinetic and Thermodynamic Studies of Chromium Ion Adsorption Using Chi-tosan from Mussel Shell [8]. Out of the four kinet-ic models tested, the adsorption process was found to follow the pseudo-second-order kinetic model with an R2-value of 0.9997; the process was physical with free sorption energy of 0.224 kJ/mol [8]. This work uses batch adsorption studies to fur-ther studies using a blend of chitosan from mus-sels and activated carbon to trap lead (II) ions from a water lead solution.  METHOD Chitosan Extraction and Characterisation. The chitosan used in this work was extracted by the process described by Abdulkarim et al. (2013), Path of Science. 2024. Vol. 10. No 9   ISSN 2413-9009 Section “Engineering, Manufacturing, and Construction”    3002 with a carbon-nitrogen ratio of 5.9 and a degree of deacetylation of 60.69% and 60.66% calculat-ed from the elemental analysis and the FTIR spectra of chitosan respectively. The FTIR spec-tra for chitosan gave a characteristic –NH2 band of 3447 cm-1 and a carbonyl group band of 1477 cm-1, also the surface area of the chitosan was determined to be 2.7225 ± 0.0741 m2/g us-ing the BET machine [9]. Preparation of lead solution. 0.256 g of Pb(NO3)2 was added to 1000 ml of deionised water to syn-thesise the stock solution from which subsequent solutions were obtained. To obtain the desired concentration in this research, 1 ml of the stock solution was further dissolved in 1 dm3 of dis-tilled water to obtain a concentration of 0.16 mg/l of lead (II) ions. Sorbent Preparation and Loading. The 2.5 g of the commercially obtained activated carbon was mixed with 0.5 g of the chitosan sample, turned into 100 ml of Pb salt solution, and stirred con-tinuously for 15 minutes at a rate of 150 rpm. The mixture was then set to settle and form dis-tinct layers. The solution was then passed through a filter to retrieve the clear solution, af-ter which a buffer powder pillow was added to the mixture and shaken thoroughly. The concen-tration of lead (II) ions in the solution was then determined using the DR 2000 uv-spectrophotometer. This procedure was repeat-ed for chitosan loading at 1.0, 1.5, 2.0, 2.5 and 3.0 g respectively. The optimum dosage of the blend during the work was obtained by consider-ing the mass of chitosan that gave the highest percentage of Pb (II) ion uptake. Kinetic studies. The optimum blend obtained from both biosorbents was then used for the time study. The contact time was between 20 and 140 minutes, with a 20-minute interval in each case, thus obtaining six values.  RESULTS AND DISCUSSION The data used in investigating the kinetics of the adsorption process was obtained by checking the effect of variation of contact time on the final concentration. At a fixed dosage of 2.5 g and a temperature of 28 °C, the equilibrium time for the process was investigated. Figure 2 shows how the reductions in the ion concentration be-come almost constant from 80 minutes of ad-sorption time and became constant after 120 minutes of adsorption.  Figure 1 – Graph of concentration of Pb2+ ions (mg/l) against dosage (g) of chitosan/activated carbon blend at 25 °C, 5 minutes and 150 rpm     Figure 2 – Relationship between adsorption time and percentage lead ion uptake by the blend  Adsorption Isotherms. The data generated from the work was fit into three different adsorption isotherm models: the Langmuir, the Freundlich and the Dubinin-Radishkevich models, as illus-trated in figures 3.0, 4.0 and 5.0, respectively.  The Langmuir isotherm was derived with the as-sumption that the adsorption is a monolayer ad-sorption phenomenon on a uniform surface with a finite number of adsorption sites of which, when occupied, no further adsorption is feasible. The Langmuir isotherm equation is shown as Equation 3: 1L eL ek bCe k Cq+=      (1) where b is the Langmuir constant related to the energy of biosorption (L/mg), kL is the maximum 606570758085900 1 2 3 4Percentage Uptake (%)Adsorbent dosage (+2.5 g activated carbon)808284868890929496981000 50 100 150Percentage UptakeTime (Minutes)Path of Science. 2024. Vol. 10. No 9   ISSN 2413-9009 Section “Engineering, Manufacturing, and Construction”    3003 sorption capacity corresponding to complete monolayer coverage (mg/g), Ce is the equilibrium solute concentration (mg/l), and qe (equation 2) is sorption capacity (mg of adsorbate/g of adsor-bent).   ( )o eev C Cqm−=    (2) where v is the volume of the solution, C0 and Ce are the initial and final concentrations of the ad-sorbate, respectively, and m is the mass of the adsorbent dosage used for the adsorption.   The Langmuir adsorption isotherm can be trans-formed to a linear form to estimate the parame-ters graphically or with linear regression. A pop-ular linear form is the reciprocal linear equation (Equation 3): 1 1eee LCCq k b b= +     (3)  The Langmuir adsorption isotherm is mainly employed to describe the nature of the adsorp-tion process by determining an important pa-rameter RL (Equation 4):  11LoRbC=+     (4)  The value of RL indicates the type of the isotherm to be either unfavourable (RL>1), linear (RL =1), favourable (0<RL<1) or irreversible (RL = 0). RL is a positive number whose magnitude determines the feasibility of the adsorption process [10]; from the Langmuir plot, it can be seen that the R2 value is 0.9776, which is the highest compared to the other isotherm models fitted with the ad-sorption data. From Table 1, the calculated RL= 0.0131; thus, the adsorption is favourable.  Table 1 – Freundlich, Langmuir and D-R constants determined from the isotherms plotted Isotherm R2 Slope Intercept bF or qD aF n kL b or BD RL Langmuir 0.9776 0.2131 0.0042 - - - 50.7381 4.6926 0.0131 Freundlich 0.9392 0.3387 1.7997 0.3387 9.3027 2.9525 - - - D-R 0.9393 -0.3518 2.2866 9.8414 - - - 7.05E-05 -   Figure 3 – Langmuir isotherm plot using the reciprocal linear equation  Figure 4 below shows the plot using the Freun-dlich isotherm model. It is an empirical equation and can be employed to describe heterogeneous systems expressed as follows: Fbe f eq a C=      (5)   Figure 4 – Freundlich isotherm plot  The Freundlich isotherm was derived with the assumption of an exponentially decaying sorp-tion site energy distribution [9]. The linearised Freundlich equation is shown as Equation 6: ln ln lne F F eq a b C= +    (6)  y = 0,2131x + 0,0042R² = 0,977600,0050,010,0150,020,02 0,03 0,04 0,05 0,06Ce/qe(g/l)Ce (mg/l)y = 0,3387x + 2,2303R² = 0,939200,20,40,60,811,21,4-4 -3,5 -3 -2,5ln qeln CePath of Science. 2024. Vol. 10. No 9   ISSN 2413-9009 Section “Engineering, Manufacturing, and Construction”    3004 Some critical parameters can be deduced from the Freundlich isotherm, which can help charac-terise the nature of the adsorption. The n or 1/bF value indicates the degree of non-linearity be-tween solution concentration and adsorption as follows: if 1/bF =1, then adsorption is linear; if 1/bF< 1, then adsorption is a chemical process; if 1/bF> 1, then adsorption is a physical pro-cess [11]. From the plot (Figure 4), the R2 value is high (0.9392) but less than that of the Langmuir iso-therm, and from Table 1, the value of n or 1/bF calculated is 2.9525, which is greater than unity; thus, the adsorption process in this case is domi-nantly physical.  The free sorption energy (Es). This parameter fur-ther confirms whether the adsorption process is either physisorption or chemisorption [9]. The sorption energy (Es) can easily be calculated us-ing the Dubinin-Radishkevich (D-R) isotherm given as:  21exp( [ ln(1 )] )e D Deq q B RTC= − +   (7)  Some authors have reported that the characteris-tic sorption curve is related to the porous struc-ture of the sorbent [12]. The D-R isotherm can be written in a linear form as:  1ln ln 2 ln(1 )e D Deq q B RTC= − +   (8) where qD is the D-R isotherm constant, BD is re-lated to the free energy of sorption per mole of the sorbate as it migrates to the surface of the adsorbent from an infinite distance in the solu-tion [12].   The relationship between the free energy of sorption (Es) and BD is given by Equation 9:  1(2 )sDEB=     (9)  The mean free energy of sorption gives infor-mation about the biosorption mechanism, physi-cal or chemical. Suppose Es value is between 8 and 16 (kJ/mol); the sorption process follows chemisorption, and if Es<8 (kJ/mol), the sorption process is of a physisorption [13]. The sorption energy was calculated to be Es= 0.0842 kJ/mol, which further confirms the deduction made from the Freundlich isotherm that the adsorption pro-cess was physical.   Figure 5 – Dubinin-Radishkevich (D-R) isotherm  Determination of kinetic models for chromium (VI) removal using chitosan. Three kinetic models were tested to determine the model describing the kinetics of lead (II) ion removal from lead wa-ter solution using an activated carbon/chitosan blend. The essence of kinetic investigation is de-termining the decisive stage in the adsorption reaction rate. Therefore, using kinetic models to fit the time-dependent experimental data is vital to the adsorption study [14].  Figure 6 shows the plot obtained using the inte-grated linear form of the pseudo-first-order ki-netic model proposed by Lagergren (Equa-tion 10).  ln( ) lne t eq q q kt− = −     (10) where qe is the amount of chromium (VI) ion ad-sorbed at equilibrium (mg/g), qt is the amount of chromium (VI) ion adsorbed at time t (mg/g), k is the first order rate constant (min-1) and t is the time (min).   Hence, a linear trace is expected between the two parameters log (qe–qt) and t, provided the bio-sorption follows the pseudo-first-order kinet-ics [8]. The plot shows an R2 value of 0.835. y = -0,3518x + 2,2866R² = 0,93930,000,200,400,600,801,001,201,402,9 3,1 3,3 3,5 3,7 3,9ln qeln(1+1/ce)Path of Science. 2024. Vol. 10. No 9   ISSN 2413-9009 Section “Engineering, Manufacturing, and Construction”    3005  Figure 6 – Testing the Pseudo First-Order Kinetic model  The second-order kinetic model was also tested using the generated data from the adsorption process. The integrated form of the model (Equa-tion 11) is given as:  21 1e ok tC C= +      (11)  The plot obtained using Equation 11 is presented in Figure 8. It is visible from the R2 values that the pseudo-first-order kinetic model fits better with the generated experimental data than the second-order kinetic model. Figure 9 shows the behaviour of the data when using the pseudo-second-order kinetic model. The equation used for the plot is presented as Equation 12.  221 1t e ettq k q q= +     (12)    Figure 8 – Testing the Second-Order Kinetic Model   Figure 9 – Testing the Pseudo Second Order Kinetic Model  The pseudo-second-order kinetic model gave the highest R2 value of 0.9981 (almost close to unity). Thus, the adsorption can be said to follow the pseudo-second-order kinetic model.  Table 2 – Summary of evaluated constants obtained from the tested kinetic models Kinetic model R2 Slope Intercept Rate constant Other constants Pseudo-first order 0.8350 -0.0498 1.1506 0.0498 qe=-3.1600 Second order 0.7610 3.1147 6.2100 3.1147 C0=0.16 Pseudo-second order 0.9981 0.3004 1.9984 0.0452 qe=3.3290  CONCLUSIONS The optimum dosage of the chitosan/activated carbon blend was determined to be 5 g (2.5 g ac-tivated carbon and 2.5 g chitosan). The initial Pb2+ concentration was 0.16 mg/l. At optimum dosage, the percentage uptake was 83.75%, and 0.134 mg/l of Pb2+ was removed, while at an equilibrium contact time of 120 minutes, the per-centage uptake was 98.75%. The Langmuir plot gave the best fit with an R2 value of 0.9776, and since the RL value is 0.0131, which is between 0 y = -0,0498x + 1,1506R² = 0,894-4,50-4,00-3,50-3,00-2,50-2,00-1,50-1,00-0,500,000,500 50 100 150ln (qeq-qt)Time t (min)y = 3,1147x + 6,21R² = 0,885501002003004005006000 50 100 1501/Ce(l/mg)Time t (min)y = 0,3004x + 1,9984R² = 0,99810102030400 50 100 150t/qt (min.g/mg)time t (min.)Path of Science. 2024. Vol. 10. No 9   ISSN 2413-9009 Section “Engineering, Manufacturing, and Construction”    3006 and 1 the adsorption is favourable. Also, accord-ing to [11], the adsorption is physical with 1/bF value greater than unity. This was later con-firmed by the sorption energy (0.0842 kJ/mol) calculated using the Dubinin-Radishkevich iso-therm, which is within the range for physisorp-tion processes. Out of the three kinetic models tested, the data generated fits best with a pseu-do-second-order plot.   REFERENCES 1. Lide, D. (2007). Handbook of Chemistry (88th ed.). New York: CRC Press. 2. WHO. (2022, August 31). Lead in drinking-water: Health risks, monitoring and corrective actions. Retrieved from https://www.who.int/publications/i/item/9789240020863 3. Wani, A. L., Ara, A., & Usmani, J. A. (2015). Lead toxicity: a review. Interdisciplinary Toxicology, 8(2), 55–64. doi: 10.1515/intox-2015-0009 4. Kalut, S. A. (2008). Enhancement of Degree of Deacetylation of Chitin in Chitosan Production. Retrieved from https://core.ac.uk/download/pdf/159177295.pdf 5. Kim, S.-K. (Ed.). (2010). Chitin, Chitosan, Oligosaccharides and Their Derivatives. doi: 10.1201/ebk1439816035 6. Schmuhl, R., Krieg, H., & Keizer, K. (2004). Adsorption of Cu(II) and Cr(VI) ions by chitosan: kinetics and equilibrium studies. Water SA, 27(1). doi: 10.4314/wsa.v27i1.5002 7. Shanmugapriya, A., Ramya, R., Ramasubramaniam, S., & Sudha, P. N. (2011). Studies on removal of Cr(VI) and Cu(II) ions using Chitosan grafted-polyacrylonitrile. Retrieved from https://www.scholarsresearchlibrary.com/articles/studies-on-removal-of-crvi-and-cuii-ions-using-chitosangrafted-polyacrylonitrile.pdf 8. Isa, M. T., Abdulkarim, A., Muhammad, J., Ameh, A., & Abdulsalam, S. (2014). Kinetic and Thermodynamic Studies of Chromium Ion Adsorption Using Chitosan from Mussel Shell. Chemical and Process Engineering Research, 21, 43–51. 9. Abdulkarim, A., Isa, M. T., Ameh, A. O., & Muhammad, J. A. (2014). Chromium Ion Adsorption Using Chitosan from Mussel. IOSR Journal of Applied Chemistry, 7(1), 24–28. doi: 10.9790/5736-07122428 10. Srividya, K., & Mohanty, K. (2009). Biosorption of hexavalent chromium from aqueous solutions by Catla catla scales: Equilibrium and kinetics studies. Chemical Engineering Journal, 155(3), 666–673. doi: 10.1016/j.cej.2009.08.024 11. Akl M. Awwad. (2012). Biosorption of copper(II) and lead(II) ions from aqueous solutions by modified loquat (Eriobotrya japonica) leaves (MLL). Journal of Chemical Engineering and Materials Science, 3(1). doi: 10.5897/jcems11.061 12. Ho, Y. S., Porter, J. F., & McKay, G. (2002). Equillibrium Isotherm Studies for the Sorption of Dialent Metal Ions into Peat:Copper Nickel and Lead Single Component Systems. Water, Air, and Soil Pollution, 141(1/4), 1–33. doi: 10.1023/a:1021304828010 13. Kianfar, S., Moheb, A., & Ghaforian, H., (2012). Equilibrium, Kinetiic and Thermodynamic Studies on Solution Using a Spore Forming Bacillus Issolated from Waste Water of a Leather Factory. World Academy of Science, Engineering and Technology, 69, 481–485. 14. El-Nafaty, U., Muhammad, I., & Abdulsalam, S. (2013). Biosorption and Kinetic Studies on Oil Removal from Produced Water Using Banana Peel. Civil and Environmental Research, 3(7), 125–136.  

Adsorption Study of Pb (II) Ion Removal From Lead Solution Using a Blend of Activated Carbon and Chitosan From Mussel Shells

https://pathofscience.org/index.php/ps/article/download/3132/1552

Adsorption Study of Pb (II) Ion Removal From Lead Solution Using a Blend of Activated Carbon and Chitosan From Mussel Shells

Abstract

Similar works

Full text

Available Versions

Traektoria Nauki