SEPARATION SCIENCE AND TECHNOLOGY 2018, VOL. 53, NO. 7, 1124–1131 https://doi.org/10.1080/01496395.2017.1340955
Highly efficient and magnetically separable palm seed-based biochar for the removal of nickel Mustafa Gazi
a
, Akeem Adeyemi Oladipo
a,b
, and Kola A. Azaloka
a Polymeric Materials Research Laboratory, Chemistry Department of Eastern Mediterranean University, Famagusta, Turkey; bFaculty of Engineering, Cyprus Science University, Girne, TRNC, Turkey
ABSTRACT
ARTICLE HISTORY
Magnetic biocomposite (MB) was fabricated by co-precipitation of palm seed-based biochar in the presence of Fe3O4 particles. The MB sorption behaviour was investigated using nickel as the target pollutant. The MB characterisation revealed that its maintained micro-mesoporous character and high saturation magnetisation (65.8 Am2/kg) enable it to be separated from a solution using a magnet. The nickel removal efficiency of MB, 87% (28 mg/g), was achieved at pH 3; however, this was reduced to 45–75% (15–24 mg/g) in the presence of competing ions. The isotherms and kinetics studies revealed a monolayer interaction via a two-stepped sorption mechanism.
Received 15 December 2016 Accepted 7 June 2017
Introduction The boom in industrialisation globally has led to the monumental use of heavy metals, resulting in increased flow of metal-based materials in the aquatic environment.[1] Among these metals, nickel is one of the most used in the manufacturing process of batteries, coins, super alloys, stainless steel, and sintered metal coatings.[2] Based on animal and human studies, nickel carbonyl is ascertained as the most severely toxic nickel compound, causing devastating damage to the respiratory system in humans and animals.[3] Hence, the removal of nickel from aqueous medium is extremely necessary. Several techniques have been employed for the recovery, removal and reuse of nickel from aqueous solutions. The selection of any of these techniques is dependent upon the initial concentration of nickel, environmental sustainability of the technique, selectivity and cost.[3] Among these techniques, adsorption involving the chemical and/or physical adhesion of pollutants to the surfaces is a good alternative to conventional processes.[2–4] The intrinsic features of adsorption processes are effectiveness to remove pollutants at varied concentrations, cost effectiveness and elimination of by-product production that requires additional treatment.[3] Recently, adsorption using agricultural wastes has been highlighted as a potential treatment technology owing to availability, multiple sorption sites and lower cost. [5] Despite the efficacy of these agricultural wastes, there is the difficulty of separating or recovering the material after
Adsorption; biomagnetic separation; kinetics; nickel removal; palm seed biochar
use. Also, poor selectivity and stability limit their wider industrial applications.[5–7] Waste palm seeds are unused environmentally friendly resources, available in large quantities and have the potential to be utilised as economic adsorbents. However, studies on waste palm seeds as an adsorbent or precursor for fabrication of high-performance biochar are less. Herein, magnetic palm seed-based biochar (MB) was fabricated and utilised for removal of nickel from simulated effluent under various operating conditions. MB could easily be recovered after treatment due to its magnetic property. MB was characterised using various techniques for physico-chemical properties. Obtained results revealed that the magnetisation also increases the stability and adsorption capacity of palm seed-based biochar. The sorption mechanism was examined, and the potential of MB regeneration using four regenerants was performed.
Experimental Materials and equipment Analytical grade reagents were used. Palm seeds were obtained within the Eastern Mediterranean University campus, North Cyprus. Reagent grade of nickel nitrate hexahydrate, sodium hydroxide, ferrous and ferric sulphate, hydrochloric acid, H2SO4 were purchased from Sigma-Aldrich (Dermasdat, Germany). The laboratory pH meter (HANNA, model; HI 98127) was employed to
CONTACT Mustafa Gazi
[email protected]; Akeem Adeyemi Oladipo
[email protected] Chemistry Department of Eastern Mediterranean University, Famagusta, TRNC via Mersin 10, Turkey. Colour versions of one or more of the figures in the article can be found online at www.tandfonline.com/lsst. © 2017 Taylor & Francis
KEYWORDS
Polymeric Materials Research Laboratory,
SEPARATION SCIENCE AND TECHNOLOGY
determine the pH of solutions. A conventional oven (BINDER GmbH, Model BD115-EZ,Tuttlingen, Germany) was used for drying the raw materials. A muffle furnace (Nabertherm GmbH model, Lilienthal, Germany) was used for calcination of the samples. The nickel concentration was analysed by UV–Vis spectrometer (Beijing, Version 5.0, T80+, Beijing, China). The thermogravimetric data of the prepared adsorbents were obtained using TGA– DTA machine from HITACHI (STA7300, IL, US). Preparation of magnetic palm seed-based biochar Pre-washed palm seeds were husked, washed several times with distilled to remove impurities and then dried in the conventional oven at 80°C for 48 h. The dried samples were subjected to pyrolysis at 600°C for 2 h under oxygen-limited conditions. After pyrolysis, the residues were mixed with HCl (0.1 mol/L) to remove suspended ash. Magnetic palm seed-based biochar (MB) was prepared as described by Oladipo and Gazi.[5] Ferrous and ferric solutions were prepared from ferrous sulphate (FeSO4·7H2O, 8.35 g) and ferric chloride hexahydrate (FeCl3·6H2O, 15 g) and with 200 mL deionised water. Then, the Fe2+/Fe3+ mixed solution was dropped into the biochar suspension (30 g/200 mL of distilled water). The pH of the mixture was adjusted to 10 with a 5 mol/L NaOH solution and stirred vigorously at 30°C for 1 h. Finally, the magnetic biochar was filtered, rinsed with ethanol and distilled water several times, and then dried at 80°C as shown in Fig. 1. Adsorption A stock solution of nickel (1000 mg/L) was prepared by dissolving 4.95 g of Ni (NO3)2.6H2O in 1 L of deionised
1125
water. Working solutions were prepared via serial dilutions of the stock. The adsorptive potential of MB was evaluated via a batch system. The effect of pH on nickel (II) adsorption was examined by agitating 0.5g of MB in 25 mL of nickel solution (200mg/L) at different pH values (3–10). The effect of adsorbent dose (0.25–1.0 g) and the contact time (20–720 min) were investigated at 200 rpm. The effect of initial nickel concentration and the equilibrium studies were examined. Periodically, the magnetic biochar was separated by an external magnet from the bulk phase, and the residual nickel concentration is analysed at 232 nm. The nickel uptake capacity (qe) and removal efficiency (R%) were obtained using Eqs. 1 and 2, respectively[6,7]: C0 Ce qe ¼ V mMB C0 Ce R %Ni2þ ¼ 100 C0
(1) (2)
Results and discussion Characterisation The specific surface areas of the palm seed powder (PSP), Fe3O4 and MB were determined as 145.5, 123.8 and 135 m2/ g, respectively. The physico-chemical analyses of the materials are presented in Table 1. The Brunauer-Emmet-Teller surface area (SBET) was measured with N2 adsorption at 77 K according to the BET method. According to the BET results, the SBET of MB decreased from 145.5 to 135 m2/g after magnetic modification due to the iron oxide that is formed on the biochar surface. The magnetic analysis of MB (figure not shown) showed that the MB contained substantial amounts of iron oxide, which likely consisted of iron oxide particles that formed on the surface of the MB.[8] Effect of initial solution pH The influence of the solution pH on the uptake of nickel from aqueous solution was investigated at room temperature. The maximum nickel uptake occurred at pH 3 Table 1. Physico-chemical analysis of PSP, Fe3O4 and MB. Parameters
Figure 1. Picture of as-prepared magnetic palm seed-based biochar.
Yield (%) Weight loss (%) Bulk density (gmL−1) Ash content (%) Moisture content (%) pHpzc Saturation magnetization(emu/g) pH value Coercivity (Oe)
PSP
Values Fe3O4
MB
61 39 0.5071 2.73 0.6 6.3 0 6.5 0
29.87 70.13 0.591 0 0.9 7.0 88.9 7.3 123.8
50.42 49.58 0.754 0 0 2, 5 65.8 4.6 135.8
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M. GAZI ET AL.
b 100
a Desorption Adsorption
Desorption
Desorption using HCl
Desorption using H2SO4
Adsorption
80
60
Efficiency (%)
Efficiency (%)
100
40
50
20
0
0 1
2
3
4
5
6
7
1
2
3
c 100
d
Desorption using H2O
Desorption
4
5
6
7
Cycle number
Cycle number
60
Desorption Desorption using NaOH Adsorption
Adsorption
80
Efficiency (%)
Efficiency (%)
40 60
40
20 20
0
0 1
2
3
4
5
6
7
1
Cycle number
2
3
4
5
6
7
Cycle number
Figure 8. Adsorption-desorption cycles using (a) HCl (b)H2SO4 (c) H2O (d) NaOH regenerants.
MB was influenced by various parameters and maximum uptake occurred at pH 3. The removal efficiency increased steadily with increases in temperature, which indicates an endothermic sorption process. Langmuir model evidently described the sorption behaviour of MB and Ni2+ with high correlation coefficient R2 (0.997–0.999) and very low error values, χ2 (0.0133–0.0551). The adsorption rate is chemically controlled, and intra-particle diffusion played a role in the process. The MB can withstand successive use and reuse without loss of stability or activity.
Acknowledgements Kola A. Azalok would like to thank the Asmarya University (Faculty of Education) Zliten-Libya for supporting this work. The authors would also like to thank the organising committee of 4th International Conference on Methods and Materials for Separation: SEPARATION SCIENCE - THEORY AND PRACTICE 2016, Poland.
ORCID Mustafa Gazi http://orcid.org/0000-0001-7736-752X http://orcid.org/0000-0003Akeem Adeyemi Oladipo 3715-5922
References [1] Barakat, M.A. (2010) New trends in removing heavy metals from industrial wastewater. Arabian Journal of Chemistry, 4: 361–377. [2] Shrestha, R.M.; Varga, M.; Yadav, I.V.A.P.; Pokharel, B.P.; Pradhananga, R.R. (2014) Removal of Ni (II) from aqueous solution by adsorption onto activated carbon prepared from lapsi (Choerospondias axillaris) seed stone. Journal of the Institute of Engineering, 9: 166–174. [3] Oladipo, A.A.; Gazi, M. (2015) Nickel removal from aqueous solution by alginate-based composite beads: Central composite design and artificial neural network modeling. Journal of Water Process Engineering, 8: e81–e91. [4] Qin, B.; Luo, H.; Li, G.; Zhang, R.; Chen, S.; Huo, L.; Luo, Y. (2012) Nickel ion removal for wastewater using the microbial electrolysis cell. Bioresource Technology, 121: 458–461. [5] Oladipo, A.A.; Gazi, M. (2015) Two-stage batch sorber design and optimization of biosorption conditions by Taguchi methodology for the removal of acid red 25 onto magnetic biomass. Korean Journal of Chemical Engineering, 32: 1864–1878. [6] Oladipo, A.A.; Gazi, M. (2014) Enhanced removal of crystal violet by low cost alginate/acid activated bentonite composite beads: Optimization and modeling
SEPARATION SCIENCE AND TECHNOLOGY
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
using non-linear regression technique. Journal of Water Process Engineering, 2: 43–52. Ghasemi, M.; Ghasemi, N.; Azimi-Amin, J. (2014) Adsorbent ability of treated Peganum harmala-L seeds for the removal of Ni (II) from aqueous solutions: Kinetics, Equilibrium and Thermodynamic studies. Indian Journal of Materials Science, 2014: 459–674. Ding, Z.; Hu, X.; Wan, Y.; Wang, S.; Gao, B. (2016) Removal of lead, copper, cadmium, zinc, and nickel from aqueous solutions by alkali-modified biochar: Batch and column tests. Journal of Industrial and Engineering Chemistry, 33: 239–245. Lam, Y.F.; Lee, L.Y.; Chua, S.J.; Lim, S.S.; Gan, S. (2016) Insights into the equilibrium, kinetic and thermodynamics of nickel removal by environmental friendly Lansium domesticum peel biosorbent. Ecotoxicology and Environmental Safety, 127: 61–70. Kooh, M.R.R.; Dahri, M.K.; Lim, L.B.L.; Lim, L. H .; Malik, O., A. (2016) Batch adsorption studies of the removal of methyl violet 2B by soya bean waste: Isotherm, Kinetics and artificial neural network modeling. Environmental Earth Science, 75: 783. Kannan, A.; Thmbidurai, S. (2008) Removal of hexavalent chromium from aqueous solution using activated carbon derived from palmyra palm fruit seed. Bulletin of Chemical Society of Ethiopia, 22: 183–196. Matouq, M.; Jildeh, N.; Qtaishat, M.; Hindiyeh, M.; Al Syouf, M.O. (2015) The adsorption kinetics and modeling for heavy metals removal from wastewater by Moringa pods. Journal of Environmental Chemical Engineering, 3: 775–784. Sheshdeh, R.K.; Nikou, M.R.K.; Badii, K.; Limaee, N.Y.; Golkarnarenji, G. (2014) Equilibrium and kinetics studies for the adsorption of basic red 46 on nickel oxide nanoparticles-modifies diatomite in aqueous solution. Journal of the Taiwan Institute Chemical Engineers, 45: 1792–1802. Oladipo, A.A.; Gazi, M. (2016) Uptake of Ni2+ and Rhodamine B by nano-hydroxyapatite/alginate composite beads: Batch and continuous-flow systems. Toxicological Environmental Chemistry, 98: 189–203. Villaescusa, I.; Martinez, M.; Miralles, N. (2000) Heavy metal uptake from aqueous solution by cork and
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
1131
yohmibe bark waste. Journal of Chemical Technology and Biotechnology, 75: 812–816. Nadeem, R.; Zafar, M.N.; Afzal, A.; Hanif, M.A.; Saeed, R. (2014) Potential of NaOH pretreated Mangifera indica waste biomass for the mitigation of Ni(II) and Co(II) from aqueous solution. Journal of the Taiwan Institute of Chemical Engineers, 45: 967–972. Sun, Y.; Yue, Q.; Gao, B.; Gao, Y.; Xu, X.; Li, Q.; Wang, Y. (2014) Adsorption and cosorption of ciprofloxacin and Ni (II) on activated carbon-mechanism study. Journal of the Taiwan Institute of Chemical Engineering, 45: 681–688. Heidari, A.; Younesi, H.; Mehraban, Z.; Heikkinen, H. (2013) Selective adsorption of Pb(II), Cd(II), and Ni(II) ions from aqueous solution using chitosan-MAA nanoparticles. International Journal of Biological and Macromolecules, 61: 251–263. Lopez, E.; Soto, B.; Arias, M.; Nunez, A.; Rubinos, D.; Barral, M.T. (1998) Adsorbent properties of red mud and its use for wastewater treatment. Water Research, 32: 1314–1322. Tran, H.V.; Tran, L.D.; Nguyen, T.N. (2010) Preparation of chitosan/magnetite composite beads and their application for removal of Pb(II) and Ni(II) from aqueous solution. Materials Science and Engineering C, 30: 304–310. Hawari, A.H.; Mulligan, C., N. (2006) Biosorption of lead (II), cadmium (II), copper (II) and nickel (II) by anaerobic granular biomass. Bioresource Technology, 97: 692–700. Laus, R.; Costa, T.G.; Szpoganicz, B.; Favere, V.T. (2010) Adsorption and desorption of Cu (II), Cd (II), and Pb (II) ions using chitosan crosslinked with epichlorohydrin-triphosphate as the adsorbent. Journal of Hazardous Materials, 183: 233–241. Inyang, M.I.; Gao, B.; Yao, Y.; Xue, Y.; Zimmerman, A.; Mosa, A.; Pullammanappallil, P.; Ok, Y.S.; Cao, X. (2015) A review of biochar as a low-cost adsorbent for aqueous heavy metal removal. Critical Reviews in Environmental Science and Technology, 46: 1574–6537. Erol, S.; Ozdemir, M. (2014) Removal of nickel from aqueous solution using magnetic tailing. Desalination and Water Treatment, 57: 5810–5820.
