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Background: In this present work, we synthesized zero-valent iron nanoparticles (ZVIN) using reproducible Calotropis gigantea (CG) flower extract served as both reducing and stabilizing agent by completely green approach. ZVIN are widely used in contaminated water treatment and can be prepared by several different methods. Method: Iron nanoparticles formed in this method are mainly ZVIN and were characterized by the various physicochemical techniques, viz, ultraviolet-visible absorption spectroscopy (UV-vis), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Results: FT-IR and UV-vis absorption spectra reveal that the polyphenols present in the CG flower extract may be responsible for the reduction and stabilization of the ZVIN. SEM images show some agglomeration among the particles and the average size of the particles in the range of 50–90 nm. ZVIN tend to agglomerate, resulting in a significant loss of reactivity. To overcome this problem, we have synthesized ZVIN that are immobilized on biomaterial with the help of chitosan. This low-cost sorbent was used to remove organic pollutants from waste water. Conclusions: Herein, we report the percentage of removal of methylene blue (MB) and aniline by synthesized sorbent from contaminated water. The adsorption isotherms of Langmuir and Freundlich models have been used to explain experimental equilibrium adsorption data. The adsorption of MB and aniline on sorbent follows pseudo-second order kinetics. Keywords: Green synthesis, Zero-valent iron nanoparticles, Calotropis gigantea flower extract, Chitosan, Methylene blue, Aniline Background leads the formation of dazzling contaminants. Moreover, Nowadays, environmental pollution is the perilous problem an anaerobic degradation of azo dyes prevails in the of all over the world. Especially contamination of water production of carcinogenic and highly toxic amines. So originates from different paths and causes great damage to there is a conclusive need of destruction of this hazardous the biosphere (Wang et al. 2014a, b). Industrial effluents waste from industrial effluents before disposal to the envir- from textile, printing, glass, paint, food, ceramic, pharma- onment. Many kinds of chemical, physical, and biological ceutical, paper, polymers, etc. preponderantly contain processes have been developed for the remediation of water organic waste such as synthetic dyes (Wanyonyi et al. 2014; pollution, including microbial degradation, filtration, Rebitanim et al. 2012). Trivial amounts of dye residues also coagulation, membrane separation, and others. But all bestow their characteristic color to the wastewater, which these methods involve some disadvantages and limitations like high cost and poor removal efficiency (Sttle et al. 2015). Earlier reports showed that a lot of research has * Correspondence: firstname.lastname@example.org Department of Chemistry, University College of Science, Osmania University, been done on the photo-catalytic degradation of synthetic Hyderabad, Telangana State 500007, India © The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Sravanthi et al. Journal of Analytical Science and Technology (2018) 9:3 Page 2 of 11 dyes. But in the dislodgement process of organic waste, citric acid, and chitosan (Madhavi et al. 2013; Morales et al. adsorption is supposed to be preferable over photo- 2013) as stabilizing or capping agents. Stabilizer molecules catalytic degradation, which sometimes leads toxic prevent attractive Vander Waals and magnetic forces by intermediates. providing strong inter-particle electrostatic repulsions. Nanotechnology is an immortally patulous area with In recent years, ZVIN are widely prepared by plant enormous applications in various fields including food, extract-mediated liquid phase bio-reduction of ferrous agriculture, medical, pharmaceutical, catalysis, optical, or ferric salt solutions. The peculiarity of this liquid and pollution control in a broad way (Shukla and Iravani. phase reduction is that it has been carried out at room 2017). In recent times, nanoscale zero-valent iron has temperature and generally completes within few minutes. received much attention from research areas like remedi- Furthermore, it involves mixing of aqueous solutions of ation of contaminated water and soil due to its high plant extract and ferric salt in which hazardous materials specific surface area, small particle size, and majestic are neither used nor generated. In general, plant extracts reactivity of surface sites (Lanlan et al. 2014; Mikhak et al. comprised phenols, flavonoids, terpenoids, proteolytic 2017). Apart from that, zero-valent iron nanoparticles enzymes, etc., which eventually act as reducing and (ZVIN) follows the maximal tenets of green chemistry as capping agents in the production of ZVIN. Based on a non-toxic, inexpensive, and environmentally compatible the notion of green chemistry, previously ZVIN are material (Li et al. 2006; Zhipan et al. 2014). If iron reacts synthesized from extracts like tea leaves (Nadagouda et with water, it forms a thin oxide layer known as goethite al. 2010), eucalyptus leaves (Wang et al. 2014a, b), vine (FeOOH) and hydrogen gas (Li and Zhang 2006). Goeth- leaves (Machado et al. 2013), Rosa damascene, Thymus ite has more affinity towards contaminates (Zhang et al. vulgaris,and Urtica dioica (Mehdi et al. 2017). But the 2014). Thus zero-valent iron core and iron hydroxides recent observations showed that the sorption and dis- have the shells which provide a characteristic core-shell persion capacity of ZVIN increased by the support of por- structure to ZVIN with unique redox properties (Yan et ous materials like clays, resins, and carbon materials (Shu al. 2012; Ritu et al. 2011). Because of attractive qualities like et al. 2010; Sunkara et al. 2010). 2+ electron donating property during the oxidation of Fe to In this paper, we report the green synthesis of ZVIN 3+ Fe and existence of various mineral forms of iron, the using Calotropis gigantea (CG) flower extract as both ZVIN have been found to be more important in the ad- reducing and stabilizing agent. In addition, a novel sorption and removal of environmental pollutants (Chic- sorbent, which is the composite of as-synthesized ZVIN, goua et al. 2012; Kumar et al. 2014). ZVIN are boon biomaterial, and chitosan, was also prepared. Here, the especially in alleviating contaminants such as dyes, organic biomaterial was prepared from Pithecellobium dulce seeds, pesticides, halogenated organic compounds, inorganic ions which is used as a good supporting material to ZVIN in like nitrate, fluoride, and sulfate, viruses, nitro-aromatic dispersion and sorption process (Arshadi et al. 2014). It is compounds, PCBs and heavy metals such as Pb, As, Cr, well known that chitosan is a second most abundant poly- and Cd (Zheng et al. 2011) from polluted water. Carbon- saccharide in the world and can be obtained from natural supported ZVIN are also used in the removal of uranium chitin which is a renewable, biodegradable and nontoxic from natural and synthetic water (Richard and Crane polysaccharide. Some previous studies showed that chito- 2014). san increases removal capacity of biochar to remove heavy Several physical and chemical production methods metals from contaminated water (Zhou et al. 2013). Here, including mechanical milling (Karimi et al. 2014), the major role of chitosan is to attach fine ZVIN onto sodium borohydride (Satapanajaru et al. 2008; Madhavi the biomaterial. According to the principles of green et al. 2014), ethylene glycol (Raveendran et al. 2003), chemistry, here, we developed a new synthetic process solvothermal method (Basavaraju et al. 2011), and for sorbent, which involves eco-friendly, inexpensive, carbothermal synthesis (Allabaksh et al. 2010) have non-hazardous, and renewable materials. The synthesized been employed for the preparation of ZVIN. But ZVIN, ZVIN and sorbent were characterized for UV-vis, FT-IR, synthesized by above conventional methods, agglomerate XRD, SEM, and EDX. Here, we also discussed the effective rapidly in clusters due to Van der Waals and magnetic adsorptive removal of organic waste such as methylene forces (Qiangu et al. 2013). Sometimes ZVIN undergo blue (synthetic dye) and aniline (aromatic primary amine) oxidation by oxidants like dissolved oxygen or water from contaminated water by the synthesized sorbent. (He and Zhao 2005). Agglomeration and oxidation of ZVIN result in the formation of large particles and also Methods reduce the delivery of ZVIN to the targeted contaminant Ferric nitrate nonahydrate (FeNO ,9H O), acetic acid, 3 2 places (Kim et al. 2008). Previously stable ZVIN are sodium hydroxide (NaOH), chitosan [MW ≈ 70,000 and synthesized using biodegradable polymers or surfactants more than 80% deacetylated], ethyl alcohol, methylene such as resin, starch, carboxymethyl cellulose (CMC), blue, and aniline chemicals are all AR grade and purchased Sravanthi et al. Journal of Analytical Science and Technology (2018) 9:3 Page 3 of 11 from Sigma Aldrich chemicals. The fresh flowers of diffraction (XRD) analysis with a computer-controlled X- Calotropis gigantea and Pithecellobium dulce seeds ray diffractometer (X’pert pro diffractometer) and were collected and used for the preparation of ZVIN. equipped with a stepping motor and graphite crystal monochromator. The FT-IR spectra were analyzed by Collection of extract and biomaterial Shimadzu spectrophotometer with KBr pellet. Calotropis gigantea flowers were washed properly and were then cut into small pieces. These finely cut pieces Batch experiments of decolorization of methylene blue were grind, and 10 mg weight of flowers was mixed with Decolorization of MB experiments was carried out at 100 mL double-distilled water. It was boiled for 5 min. room temperature and at its original pH. In this study, After cooling, the solution was filtered thrice by Whatman 400 mg of sorbent material was mixed with 500 mL of no.1 filter paper to get clear extract. Dry Pithecellobium different concentrations (50–400 ppm) of MB solutions. dulce seeds were collected and washed with distilled water The mixture was stirred for certain period of time (5, 10, and were put in the oven for 48 h at 70 °C. After cooling, 15, 20, 25, 30, 40, 50, 60, 90, 120, 180, 240, 300, and the biomaterial was finely ground, washed with double- 360 min), using a magnetic stirrer to find out the effect distilled water, and oven dried at 65 °C. of contact time in the removal of MB. During the adsorption process, about 4 mL of aliquot samples was Preparation of ZVIN withdrawn from the reaction mixture by syringe at 0.01 M FeNO .9H O was prepared in double distilled certain time intervals and the sorbent was removed 3 2 water and was mixed with flower extract in 1:1 ratio. For using 0.45-μm filters. Concentration of MB, remained the reduction of Fe ions, equal volume of flower extract in solution, was determined spectrophotometrically by was added slowly to aqueous ferric nitrate solution with measuring absorbance at 665 nm. The change in the constant stirring for 15 min on a magnetic stirrer and the concentration of MB was calculated from the difference reaction was carried out at room temperature. Here, the between the initial and final equilibrium concentrations Calotropis gigantea flower extract used as both reducing of MB, and sorption efficiency or removal efficiency of and stabilizing agent. The formation of iron nanoparticles the sorbent was computed from the following equation: were indicated by the color change of solution from light pink to black. The black precipitate was washed several ðÞ c −c 0 e % of removal ¼ 100 ð1Þ times with 1:1 ethanol and water and then with double distilled water. The obtained nanoparticles were dried at 60 °C in the oven. where c and c are total dissolved and equilibrium liquid 0 e −1 phase concentrations (mg L ), respectively. For compara- Preparation of sorbent tive study, the above batch experiments were carried out A composite sample was prepared by dissolving chitosan with adsorbents, viz, synthesized ZVIN, blank, sorbent powder first in a 100 mL of 2% acetic acid solution and (1:1:0.5), sorbent (1:1:1), and sorbent (1:1:2) individually at then synthesized ZVIN were dispersed in the chitosan identical reaction conditions. solution. To the above mixture, biomaterial was added and stirred for 60 min to form a homogeneous mixture. Batch experiments of aniline removal This mixture was added drop-wise into a 500 mL of The aniline removal experiments were carried out with 1.5% NaOH solution and kept undisturbed for 15 h at the initial concentration of aniline between 50 and room temperature. The solid products were then sepa- 400 ppm in distilled water. In this study, the amount of −1 rated by decantation method and washed with deionized sorbent added to the aniline solution was 1 g L . The water to remove the excess NaOH and oven dried for conditions such as neutral pH and 30 °C temperature 24 h at 70 °C. Here the ratio of chitosan, biomaterial, were maintained throughout the experiment. Proper care and ZVIN particles in the sorbent were 1:1:0.5, 1:1:1, was taken against auto-degradation, photodegradation, and 1:1:2. For comparison, another sorbent in the 1:1 ratio and degradation by OH radical. In this typical removal of biomaterial and chitosan was also synthesized without process, the solution was kept shaking at 300 rpm and the addition of ZVIN. amount of aniline removed determined at certain time intervals such as 30, 60, 120, 180, and 360 min to know Characterization of ZVIN and sorbent the effect of contact time. At these time intervals, about UV-vis absorption analysis was carried out using UV-3600 4 mL of liquid sample was withdrawn by syringe and spectrophotometer in the range of 200–800 nm. Scanning filtered off using 0.45-μm filters. The concentration of electron microscope (SEM) imaging analysis of the aniline, remained in solution, was determined spectro- samples was conducted using a Zeiss evo 18 instrument. photometrically by measuring absorbance at 232 nm. The sample crystallinity was examined using X-ray The change in amount of aniline was calculated from Sravanthi et al. Journal of Analytical Science and Technology (2018) 9:3 Page 4 of 11 the difference between the initial and final equilibrium pattern attributed to the surface plasmon resonance concentrations of aniline. The sorption efficiency or (SPM). But with few exceptions, such characteristic removal efficiency of the sorbent was determined same UV-vis peaks are not observed for ZVIN due to the as that of MB and also the experiment was repeated high reactivity of iron, when compared to silver and with each of the sorbent material, blank, and synthesized gold.However,the decreaseinthe intensityofphyto- ZVIN. The amount of adsorbate adsorbed on the surface chemicals characteristic peak specifies the significance of sorbent at equilibrium (q ) was calculated as: of flower extract in the synthesis of ZVIN. ðÞ c −c v FT-IR analysis 0 e q ¼ ð2Þ FT-IR technique provides information about interactions mq among biomolecules of CG flower extract and metal where v (in liter) is the volume of the solution and m ions responsible for the formation and stabilization of (in gram) is the amount of adsorbent. iron nanoparticles. Figure 2a shows the spectrum of the CG flower extract and the colloidal solution of ZVIN Results and discussion stabilized in flower extract. By the deep observation of UV-vis absorption analysis FT-IR spectrum, it was noticed that, when moving from UV-vis spectral scanning procedure was carried out CG flower extract to colloidal solution of ZVIN, the −1 from 200 to 800 nm to determine the formation of peak positioned at 3359 cm (–OH and –NH stretching −1 ZVIN (Fig. 1). Initially, the flower extract had pale pink vibrations) was found to be shifted to 3361 cm and also −1 −1 color and showed higher absorption from 300 to 350 nm. peak at 1641 cm (amide) was shifted to 1642 cm with −1 It indicates that the flower extract had free phytochemicals increasing intensity. Similarly peaks at 1239 cm (amide), −1 like carbohydrates, amino acids, and lipids. After the 1083 cm (–OH bending and C–O–Cstretching), −1 −1 addition of flower extract to ferric solution, a black-colored 976 cm , and 923 cm of flower extract were shifted −1 colloidal solution was formed. The spectra of the black- to 1231, 1081, 977, and 922 cm in colloidal solution colored colloidal solution show the disappearance of strong of ZVIN respectively. Another two bands observed at −1 −1 absorption peaks at the region 300 to 350 nm and emerge 873 cm (amine) and 680 cm (aromatic alkanes) in the broad absorption at higher wavelengths, suggesting the spectrum of CG flower extract. There was a complete −1 formation of polydispersed ZVIN. During the synthesis of absence of peaks at 873 and 680 cm in FT-IR spectra of +3 0 ZVIN, the reduction of Fe ions to Fe is indicated by the ZVIN colloidal solution. The highest peaks present at −1 change in color due to excitation of electrons. Upon the 3359–3361 cm correspond to polyphenols, indicates the whole, the formation of noble nanoparticles like silver and more abundance and prominent of phenolic functional +3 0 gold are indicated by characteristic UV-vis absorption groups for the reduction of Fe to Fe . Besides that, Fig. 1 The UV-vis absorption spectra of flower extract, ferric solution, and ZVIN solution Sravanthi et al. Journal of Analytical Science and Technology (2018) 9:3 Page 5 of 11 Fig. 2 The FT-IR spectra of a ZVIN and flower extract and b blank and sorbent the more available phenolic groups provide the favorable predominantly in the sample and the diffraction peak at 2ϴ molecular arrangement for the delocalization of unpaired of 35.6° indicates the presence of Fe O (Khasim et al. 2 3 electrons. So the flower extract enthralled the property of 2011). Along with prominent diffraction peaks of iron effective scavenging of free radicals. On the other hand, nanoparticles, which demonstrate the crystallinity of ZVIN, anti-oxidant capacity and anti-radical property increases here also exist some low-intensity peaks in between the 2ϴ with the number of phenolic hydroxyl groups. The value of 20°–25° corresponding to the organic matter −1 appearance of a peak at 3359 cm and shifting to coated on the surface of ZVIN (Fazlzadeh et al. 2017). −1 3361 cm suggest that the phenolic or amine groups These results show that the CG flower extract is present in flower extract may be involved in ZVIN successfully used for the synthesis and stabilization of formation. The earlier reports (Mystrioti et al. 2015) ZVIN which can be reconciled by FT-IR analysis. Size indicate polyphenols were responsible for the reduction of ZVIN is calculated from Sherrer’s formula, given of Fe. From the spectrum, we can conclude that polyphe- below, using peak broadening profile of peak at a 2ϴ nols present in the flower extract were responsible for value of 45°. reduction and stabilization of ZVIN which also agrees 0:94 λ with UV-vis analysis. d ¼ ð3Þ FT-IR analysis of sorbent without ZVIN and with ZVIN β cosθ also carried out to find out the effect of immobilization of ZVIN on the chemical composition of biomaterial. The spectrum (Fig. 2b) reveals the presence of –OH and –NH where λ is the wavelength (1.5418 Å) and β is the full- −1 stretching vibrations (3432 cm ), –CH and –CH sym- width at half maximum (FWHM) of corresponding peak. 2 3 −1 metric and asymmetric stretching vibrations (2924 cm , The size of synthesized ZVIN calculated from Sherrer’s −1 −1 −1 2853 cm ), amides (1641 cm ,1570 cm ), and C–O equation was 30 nm. XRD patterns of both sorbent and −1 stretching vibrations in carboxylate ion (1414 cm )in blank (Fig. 3) are compared to know the surface modifi- both the sorbent without ZVIN and also in the sorbent cation of sorbent. In the XRD pattern of sorbent (1:1:2), with ZVIN. By the addition of ZVIN to the biomaterial, diffraction peak at a 2ϴ value of 45° indicates that there was no observable change in the basic chemical nanoparticles contain mostly zero-valent iron which nature of the biomaterial. These results reveal that the was mainly present on the surface of sorbent. However, by proteins (amide peak) may be responsible for the this analysis, it was clear that biomaterial and chitosan were immobilization of iron nanoparticles. good supporting materials to ZVIN for the preparation of a post grafting composite material due to prevention of XRD analysis oxidation. The XRD technique was used to determine the material and crystalline structure of iron nanoparticles. The XRD SEM and EDX analysis analysis of ZVIN is shown in Fig. 3. The peaks at 2ϴ of 45° The SEM analysis was carried out to investigate the and 65° indicate that the presence of zero-valent iron shape, crystal growth, and approximate size of ZVIN Sravanthi et al. Journal of Analytical Science and Technology (2018) 9:3 Page 6 of 11 Fig. 3 The powder XRD pattern of ZVIN, sorbent, and blank synthesized using CG flower extract. The SEM micrograph synthesis of ZVIN but the synthesized ZVIN exhibit some of synthesized ZVIN is shown in Fig. 4a, and it reveals that agglomeration which was indicated by spherical shape and the ZVIN are spherical in shape and polydispersed with also non-uniform particle size with different void space. different sizes ranging from 50 to 90 nm. These results Hence, ZVIN are dispersed on the surface of the biomaterial show that the importance of CG flower extract in the to minify the aggregation. To know the surface morphology, Fig. 4 SEM image of a ZVIN, b sorbent, and c EDX image of ZVIN Sravanthi et al. Journal of Analytical Science and Technology (2018) 9:3 Page 7 of 11 the sorbent was characterized by SEM and shown in Fig. 4b. Langmuir model It shows that the surface was smooth with many gorges and It was limited to adsorption on homogeneous surface by ZVIN arewelldispersed on thesurface of thesorbent.EDX monolayer formation, with decrease in intermolecular analysis gives the elemental status of synthesized ZVIN forces among adsorbed molecules and also uniform en- using flower extract (Fig. 4c) and revealed the proportion of ergies of adsorption with no transmigration of adsorbed iron, carbon, and oxygen atoms which were summarized in molecules (Dey et al. 2015; Eastoe and Dalton 2000). In Table 1. It can also provide qualitative as well as quantitative addition, it is used to determine the maximum adsorption information about elements that may be involved in the capacity of sorbent. The expression of Langmuir which formation of nanoparticles. In the EDX spectrum of relates molecules covered on solid surface to equilibrium ZVIN, the highest peak due to absorption of elemental concentration of liquid phase above the surface of sorbent iron indicates the presence of iron nanoparticles and is given by the following equation: another peaks corresponding to carbon and oxygen X bc m e atoms reveal the vital role of organic molecules from q ¼ ð4Þ 1 þ bc flower extract in the stabilization of ZVIN. e −1 −1 where q (mg g ) and c (mg L ) are the amount e e adsorbed on the surface of unit mass of sorbent and the Batch experiments of methylene blue decolorization and concentration of adsorbate in the solution at equilibrium aniline removal −1 respectively. X (mg g ) is the maximal adsorption Concentrations of MB and aniline remained in solution −1 capacity, and b (L mg ) is the empirical constant which were determined spectrophotometrically by measuring gives the affinity of binding sites. The Langmuir expression absorbance at 665 and 232 nm respectively. Figure 5a, b can be given in the linearized form: shows the effect of contact time on MB decolorization and aniline removal, respectively, and reveal that all the 1 1 1 adsorbent samples (blank, synthesized ZVIN, and sorbent ¼ þ ð5Þ q X bc X m e m material) showed some MB and aniline removal capacity. Among all the samples, the sorbent material (1:1:2) was The linear plots of 1/q against 1/c show the Langmuir e e found to remove the highest amount whereas lowest adsorption isotherms of MB and aniline on the surface of amount was removed by blank sample. Percentage of MB synthesized sorbent (1:1:2) (Fig. 6a, b). The values of removal rates of blank, synthesized ZVIN, and sorbent parameters X and b were calculated from slope and materials (with different ratios of biomaterial, chitosan, intercept of the straight line. The separation factor R and ZVIN) were 29.4%, 63.1%, 80.5% (1:1:0.5), 83.9% (dimensionless quantity) provides basic information about (1:1:1), and 85.5% (1:1:2) respectively within the first essential features of Langmuir adsorption isotherm. If 0 < 30 min (Fig. 5c). Percentage of aniline removal rates of R < 1, it is considered as favorable adsorption; if R >1, it L L blank, synthesized ZVIN, and sorbent materials were is considered as unfavorable adsorption; if R =0, it is 17.1%, 49.4%, 56.3% (1:1:0.5), 59.1% (1:1:1), and 74.8% considered as irreversible adsorption; if R =1, it is consid- (1:1:2) respectively after 12 h (Fig. 5d). These results ered as linear adsorption (Zheng et al. 2008). The equation showed that MB and aniline removal capacity of syn- for R is: thesized ZVIN enhanced in modified form. R ¼ ð6Þ 1 þ bc Adsorption isotherms To understand the mechanism of adsorption of MB and aniline on sorbent (1:1:2), Langmuir and Freundlich where b (L/mg) is Langmuir constant and c (mg/L) is adsorption models were applied to experimental data. the initial concentration of adsorbate. The calculated Langmuir adsorption parameters are tabulated in Table 2. Table 1 The elemental compositions and weight percentages R values indicate the favorable adsorption of MB and of ZVIN aniline on synthesized sorbent (1:1:2). Based on the value Element Weight % Atomic % of correlation coefficient (R ), it was clear that the C K 29.77 45.48 Langmuir model was well fitted to experimental data. O K 37.62 43.14 Freundlich model P K 2.49 1.48 Freundlich model assumes that adsorptions occur at Fe L 30.11 9.89 heterogeneous binding sites and formation of multilayer Totals 100.00 100.00 takes place due to interactions among adsorbed molecules Sravanthi et al. Journal of Analytical Science and Technology (2018) 9:3 Page 8 of 11 Fig. 5 Effect of contact time on percentages of concentrations (a) MB and (b) aniline and removal of percentage of (c) MB and (d) aniline as a function of composition of material Fig. 6 (a, b) Langmuir adsorption isotherms and (c, d) Freundlich adsorption isotherms for MB and aniline removal Sravanthi et al. Journal of Analytical Science and Technology (2018) 9:3 Page 9 of 11 Table 2 Langmuir and Freundlich parameters adsorption of MB and aniline on the surface of sorbent 1 1/ 2 (1:1:2) which confirms homogeneous and monolayer Isotherms X (mg/g) b (L/mg) K (mg g (L/mg) ) nR R m f L adsorption. Langmuir −3 i. MB 500 1.7 × 10 – 0.59 0.98 Adsorption kinetics ii. aniline 52.63 0.0205 – 0.33 0.93 The experiments of adsorption kinetics of MB and aniline Freundlich on the surface of sorbent (1:1:2) were carried out at room i. MB 1.88 1.29 0.95 temperature and the data well fitted to the pseudo-second ii. aniline 2.09 1.5 0.98 order kinetic model (Zheng et al. 2008; Simin et al. 2013) which can be expressed as: on the surface of adsorbent (Soon et al. 2016). The expres- k tq sion for Freundlich adsorption isotherm is as follows: t q ¼ ð9Þ 1 þ k tq q ¼ K c ð7Þ e e −1 where q (mg g ) is the amount of adsorbate adsorbed −1 −1 −1 at time t (min), q (mg g ) is the equilibrium adsorption where q (mg g ) and c (mg L ) are the amounts e e e −1 capacity of sorbent, and k (g mg min) is the second- adsorbed on the surface of unit mass of sorbent and the 2 order rate constant. To determine the values of k and concentration of adsorbate in the solution at equilibrium 2 −1 −1 1/n q from the linear form of pseudo-second order kinetic respectively. K (mg g (L mg ) ) and n are Freundlich e model was taken as: constants which indicate sorption capacity and favorability of adsorption respectively. Here, n value gives information t 1 t about heterogeneity of binding sites, magnitude of driving ¼ þ ð10Þ q k q q t e e force of adsorption. The values of n between 1 and 10 (1 < n < 10) indicate favorable adsorption (Vazquez et al. The values of k and q calculated from slope and 2 e 2007). To calculate the values of Freundlich constants intercept values of linear plot of t/q against t (Fig. 7a, b) (K and n), the equation of linear form of Freundlich are summarized in Table 3. isotherm was taken as follows: Conclusions logq ¼ logK þ logc ð8Þ f e In this paper, we report the green and novel synthesis of ZVIN by renewable and naturally occurring CG flower The linear plots of log q against log c show the extract as both reducing and stabilizing agent. UV-vis e e Freundlich adsorption isotherms of MB and aniline on absorption and FT-IR spectral data confirm that the the surface of synthesized sorbent (1:1:2) in Fig. 6c, d. polyphenols present in the flower extract are responsible Freundlich constants K and n were calculated from slope for the formation of ZVIN. The crystallinity of as- and intercept values of the straight line and all the param- synthesized ZVIN is confirmed by XRD analysis. The eters of Freundlich adsorption isotherm were summarized SEM images give the average size of synthesized ZVIN in Table 2. However, from all these parameters, it was as 50–90 nm. We also report the preparation of low-cost, concluded that the Langmuir adsorption model was eco-friendly, and efficient sorbent using synthesized well fitted than the Freundlich adsorption model to the ZVIN, biomaterial, and chitosan for the abatement of Fig. 7 (a, b) Pseudo-second order kinetic model for MB and aniline adsorption on sorbent (1:1:2) Sravanthi et al. Journal of Analytical Science and Technology (2018) 9:3 Page 10 of 11 Table 3 Pseudo-second order parameters of adsorption data He F, Zhao D, Extended abstract and presentation, in: 230th ACS National −1 2 Meeting, 28 August-1 September, Washington, DC, 2005. q (mg/g) k (g mg min) R e 2 Karimi EZ, Vahdati KJ, Zebarjad SM, Bataev IA, Bannovm AG. A novel method for −4 MB 90.9 1 × 10 0.94 fabrication of Fe catalyst used for the synthesis of carbon nanotubes. Bull Mater Sci. 2014;37:1031–8. Aniline 5.05 0.076 0.98 Khasim S, Raghavedra SC, Revanasiddappa M, Sajjan KC, Mohanalakshmi, Faisal Md. Characterization and magnetic properties of polyaniline. Bull Mater Sci 2011;34:1557-1561. aggregation of synthesized ZVIN. Here, the FT-IR analysis Kim JH, Tratnyek PG, Chang YS. Rapid dechlorination of polychlorinated dibenzo-p-dioxins by bimetallic and nanosized zerovalent iron. Environ Sci of synthesized sorbent reveals the immaculate support of Technol. 2008;42:4106–12. biomaterial to ZVIN in the preparation of sorbent. The Kumar SP, Pooja G, Kaliaperumal S. Synthesis of a green nano iron particles (GnIP) SEM analysis showed that ZVIN are well dispersed on the and their application in adsorptive removal of As(III) and As(V) from aqueous solution. Appl Surf Sci. 2014;317:1052–9. surface of the sorbent. ZVIN immobilized on biomaterial Lanlan H, Xiulan W, Zuliang C, Mallavarapu M. Green synthesis of iron act as an efficient sorbent for the adsorption of water con- nanoparticles by various tea extracts: comparative study of the reactivity. taminants MB and aniline. Langmuir adsorption model Spectrochim Acta A Mol Biomol Spectrosc. 2014;130:295–301. Li X, Elliott DW, Zhang W. Zero-valent iron nanoparticles for abatement of was a well fit to the adsorption of MB and aniline on the environmental pollutants: materials and engineering aspects. Crit Rev Solid surface of sorbent than the Freundlich model, and the State Mater Sci. 2006;31:111–22. adsorption process follows pseudo-second order kinetics. Li XQ, Zhang WX. Iron nanoparticles: the core–shell structure and unique properties for Ni(II) sequestration. Langmuir. 2006;22:4638–42. Abbreviations Nadagouda MN, Castle AB, Murdock RC, Hussain SM, Varma RS. In vitro CG: Calotropis gigantea; EDX: Energy-dispersive X-ray spectroscopy; biocompatibility of nanoscale zerovalent iron particles (NZVI) synthesized FTIR: Fourier transform infrared; MB: Methylene blue; SEM: Scanning electron using tea polyphenols. Green Chem. 2010;12:114–22. microscope; UV-vis: Ultra-violet visible; XRD: X-ray diffraction; ZVIN: Zero-valent Machado S, Stawinski W, Slonina P, Pinto AR, Grosso JP, Nouws HPA, Albergaria iron nanoparticles JT, Delerue-Matosa C. Application of green zero-valent iron nanoparticles to the remediation of soils contaminated with ibuprofen. Sci Total Environ. 2013;461-462:323–9. Acknowledgements The authors are thankful to the Head of the Department of Chemistry, Madhavi V, Prasasd TNVKV, Vijaya BRA, Ravindra RB, Madhavi G. Application of Osmania University, for providing necessary facilities. phytogenic zerovalent iron nanoparticles in the adsorption of hexavalent chromium. Spectrochim Acta A Mol Biomol Spectrosc. 2013;116:17–25. Madhavi V, Ravindra RB, Madhavi G, Prasad TNVKV, Vijay BRA. Conjunctive effect Authors’ contributions of CMC–zero-valent iron nanoparticles and FYM in the remediation of This work was designed by KS, DA, and PYS. The experimental work and chromium-contaminated soils. Appl Nanosci. 2014;4:477–84. analysis of the results were done by KS, DA, and PYS. This manuscript was Mehdi F, Kourosh R, Ahmad Z, Hossein A, Fakhraddin N, Rasoul K. A novel green written by KS, DA, and PYS. All authors read and approved the final synthesis of zero valent iron nanoparticles (NZVI) using three plant extracts manuscript. and their efficient application for removal of Cr(VI) from aqueous solutions. Adv Powder Technol. 2017;28:122–30. Competing interests Mikhak A, K Md Z, Sohrabi A, Feizian M. Nano Fe(OH) /Zeolite as a novel, green The authors declare that they have no competing interests. and recyclable adsorbent for efficient removal of toxic phosphate from water. Indian J Chem Technol. 2017;24:284–93. Publisher’sNote Morales MA, de Souza Rodrigues EC, de Amorim ASCM, Soares JM, Galembeck F. Springer Nature remains neutral with regard to jurisdictional claims in Size selected synthesis of magnetite nanoparticles in chitosan matrix. Appl published maps and institutional affiliations. Surf Sci. 2013;275:71–4. Mystrioti, Xenidis A, Sparis D, Dermatas D, Papasiopi N, Chrysochoou M. Received: 29 June 2017 Accepted: 26 December 2017 Assessment of polyphenol coated nano zero valent iron for hexavalent chromium removal from contaminated waters. Bull Environ Contam Toxicol. 2015;94:302–7. Qiangu Y, Caixia W, Jian L, Jinsen G, Fei Y, Jilei Z, Zhiyong C. Iron nanoparticles in References situ encapsulated in biochar based carbon as an effective catalyst for the Allabaksh MB, Mandal BK, Kesarla MK, Kumar KS, Reddy PS. Preparation of stable conversion of biomass-derived syngas to liquid hydrocarbons. Green Chem. zero valent iron nanoparticles using different chelating agents. J Chem 2013;15:1631–40. Pharm Res. 2010;2:67–74. Raveendran P, Fu J, Wallen SL. Completely “green” synthesis and stabilization of Arshadi M, Soleymanzadeh M, Salvacion JWL, Salimi VF. Nano scale zero-valent metal nanoparticles. J Am Chem Soc. 2003;125:13940–1. iron (NZVI) supported on sineguelas waste for Pb(II) removal from aqueous Rebitanim NZ, Ghani WW, Mahmoud DK, Rebitanim NA, Salleh MM. Adsorption solution: kinetics, thermodynamic and mechanism. J Colloid Interface Sci. of methylene blue by agricultural solid waste of pyrolyzed EFB biochar. J 2014;426:241–51. Purity Util React Environ. 2012;1:346–60. Basavaraju S, Balaji DS, Mahesh DB, Ragunandan D, Prithviraj SPM, Venkataraman Richard A, Crane TS. The removal of uranium onto carbon-supported nanoscale A. Solvothermal synthesis and characterization of acicular α- zero-valent iron particles. J Nanopart Res. 2014;16:2813. Fe O nanoparticles. Bull Mater Sci. 2011;34:1313–7. 2 3 Ritu S, Virendra M, Rana PS. Synthesis, characterization and role of zero-valent Chicgoua N, Sabine C, Richard C. Nanoscale metallic iron for environmental iron nanoparticle in removal of hexavalent chromium from chromium-spiked remediation: prospects and limitations. Water Air Soil Pollut. 2012;223:1363–82. soil. J Nanopart Res. 2011;13:4063–73. Dey S, Bhattacharjee S, Bose RS, Ghosh CK. Room temperature synthesis of Satapanajaru T, Anurakpongsatorn P, Pengthamkeerati P, Boparai H. Remediation hydrated nickel (III) oxide and study of its effect on Cr(VI) ions removal and of atrazine-contaminated soil and water by nano zero valent iron. Water Air bacterial culture. Appl Phys A Mater Sci Process. 2015;119:1343–54. Soil Pollut. 2008;192:349–59. Eastoe J, Dalton JS. Dynamic surface tension and adsorption mechanisms of surfactants at the air-water interface. Adv Colloid Interf Sci. 2000;85:103–44. Shu HY, Chang MC, Chen CC, Chen PE. Using resin supported nano zero-valent Fazlzadeh M, Rahmani K, Zarei A, Abdoallahzadeh H, Nasiri F, Khosravi R. A novel iron particles for decoloration of acid blue 113 azo dye solutions. J Hazard green synthesis of zero valent iron nanoparticles (NZVI) using three plant Mater. 2010;184:499–505. extracts and their efficient application for removal of Cr(VI) from aqueous Shukla AK, Iravani S. Metallic nanoparticles: green synthesis and spectroscopic solutions. Adv Powder Technol. 2017;28:122–30. characterization. Environ Chem Lett. 2017;15:223–31. Sravanthi et al. Journal of Analytical Science and Technology (2018) 9:3 Page 11 of 11 Simin A, Mahmoud RS, Morteza K. Adsorption kinetics and thermodynamics of vat dye onto zero-valent iron. Indian J Chem Technol. 2013;20:173–9. Soon UY, Hun MH, Biswanath M, Chang GK. Phenol adsorption on surface-functionalized iron oxide nanoparticles: modeling of the kinetics, isotherm and mechanism. J Nanopart Res. 2016;18:170–9. Sttle, Ttngo, Khanitchaidecha W, Nakaruk A. Synthesis of iron/GAC catalyst for wastewater treatment using heterogeneous Fenton reaction. Bull Mater Sci. 2015;38:1039–42. Sunkara B, Zhan JJ, He JB, McPherson GL, Piringer G, John VT. Nanoscale zerovalent iron supported on uniform carbon microspheres for the in situ remediation of chlorinated hydrocarbons. ACS Appl Mater Interfaces. 2010;2: 2854–62. Vazquez I, Rodriguez-Iglesias J, Maranon E, Castrillon L, Alvarez M. Removal of residual phenols from coke wastewater by adsorption. J Hazard Mater. 2007; 147:395–400. Wang T, Jin X, Chen Z, Megharaj M, Naidu R. Green synthesis of Fe nanoparticles using eucalyptus leaf extracts for treatment of eutrophic wastewater. Sci Total Environ. 2014a;210:466–7. Wang T, Lin J, Chen Z, Megharaj M, Naidub R. Green synthesized iron nanoparticles by green tea and eucalyptus leaves extracts used for removal of nitrate in aqueous solution. J Clean Prod. 2014b;83:413–9. Wanyonyi WC, Onyari JM, Shiundu PM. Adsorption of Congo red dye from aqueous solutions using roots of Eichhornia crassipes: kinetic and equilibrium studies. Energy Procedia. 2014;50:862–9. Yan W, Ramos MAV, Koel BE, Zhang WX. As(III) sequestration by iron nanoparticles: study of solid-phase redox transformations with X-ray photo- electron spectroscopy. J Phys Chem C. 2012;116:5303–11. Zhang E, Wang G, Long X, Wang Z. Synthesis and influence of alkaline concentration on α-FeOOH nanorods shapes. Bull Mater Sci. 2014;37:761–5. Zheng XC, Xiao YJ, Zuliang C, Mallavarapu M, Ravendra N. Removal of methyl orange from aqueous solution using bentonite-supported nanoscale zero- valent iron. J Colloid Interface Sci. 2011;363:601–7. Zhipan W, Yalei Z, Chaomeng D. Removal of phosphate from aqueous solution using nanoscale zero valent iron (nZVI). Colloids and Surfaces colloids and Surfaces A: Physicochem Eng Aspects. 2014;457:433–40. Zhou Y, Gao B, Zimmerman A, Fang J, Sun Y, Cao X. Sorption of heavy metals on chitosan-modified biochars and its biological effects. Chem Eng J. 2013;231:512–8. Zheng H, Wang Y, Zheng Y, Liang S, Long M. Equilibrium kinetics and thermodynamic studies on the sorption of 4-hydroxyphenol on Cr-bentonite. Chem Eng J. 2008;143:117–23.
"Journal of Analytical Science and Technology" – Springer Journals
Published: Dec 1, 2018
Keywords: Analytical Chemistry; Characterization and Evaluation of Materials; Monitoring/Environmental Analysis
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