Accepted Manuscript Green synthesis of iron nanoparticles using Moringa oleifera extracts and their applications: Removal of nitrate from water and antibacterial activity against Escherichia coli
Lebogang Katata-Seru, Tshepiso Moremedi, Oluwole Samuel Aremu, Indra Bahadur PII: DOI: Reference:
S0167-7322(17)33108-2 doi:10.1016/j.molliq.2017.11.093 MOLLIQ 8209
To appear in:
Journal of Molecular Liquids
Received date: Revised date: Accepted date:
12 July 2017 14 November 2017 15 November 2017
Please cite this article as: Lebogang Katata-Seru, Tshepiso Moremedi, Oluwole Samuel Aremu, Indra Bahadur , Green synthesis of iron nanoparticles using Moringa oleifera extracts and their applications: Removal of nitrate from water and antibacterial activity against Escherichia coli. The address for the corresponding author was captured as affiliation for all authors. Please check if appropriate. Molliq(2017), doi:10.1016/ j.molliq.2017.11.093
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Green synthesis of iron nanoparticles using Moringa oleifera extracts and their applications: removal of nitrate from water
PT
and antibacterial activity against Escherichia coli
Chemistry Department, Faculty of Agriculture, Science and Technology, North-West
CE
PT E
D
MA
NU
University, Mmabatho, Mafikeng 2735, South Africa
AC
1
SC
RI
Lebogang Katata-Seru1,*, Tshepiso Moremedi1, Oluwole Samuel Aremu1, Indra Bahadur1,*
*Corresponding authors:
[email protected];
[email protected]
1
ACCEPTED MANUSCRIPT ABSTRACT The importance of fabricating nanoparticles using plant extracts is being emphasized globally, as an alternative to traditional method because they are cost–effective, nontoxic, biocompatible and eco-friendly. In this study, green synthesis of iron nanoparticles (FeNPs) using leaf and seed extracts of Moringa oleifera (M. oleifera) were prepared by mixing
PT
different ratios of plant extracts with iron chloride solution. They were characterized using
RI
techniques such as dynamic light scattering, UV–Visible spectroscopy (UV-Vis), X-ray
SC
diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The UV-Vis spectrum of M. oleifera leaf (MOL) and seed (MOS) based
NU
on FeNPs showed absorption at 210 and 240 nm, respectively. In addition, the green application of synthesized nanoparticles for the removal of nitrate ion (NO3-) from surface
MA
and ground water was also investigated. The batch adsorption results showed an enhanced removal of NO3- by 85 % and 26 % MOS-FeNPs and MOL-FeNPs respectively as compared
D
to M. oleifera extracts. Furthermore, the antibacterial activity illustrated that the maximum
PT E
zone of inhibition against Escherichia coli was observed by MOS-FeNPs (6 mm), followed by MOL-FeNPs (5 mm). FeNPs were successfully fabricated using M. oleifera extracts,
AC
CE
giving an alternative method to nitrate removal from surface and ground water.
Keywords: Nitrate removal, iron nanoparticles, M. oleifera, antibacterial activity, MOSFeNPs and MOL-FeNPs.
2
ACCEPTED MANUSCRIPT 1. Introduction Water is the most important component on earth for living organisms. Regrettably the quality of water is changing day by day due to population growth and environmental changes [1]. Ground and surface water serve as the main sources of drinking water in rural and urban areas; however availability of potable water is still a major concern [2]. According
PT
to the latest report by World Health Organization (WHO), 663 million people rely on reliable
RI
sources, and over 159 million depend on surface water. Annually, millions of people die from
SC
diseases such as diarrhoea and cholera, which are caused by poor quality water [3]. High concentrations of nitrate (NO3-) in water pose serious threats to drinking water supplies and
NU
promote eutrophication [3]. In addition, according to the United States Environmental Protection Agency (US EPA) high levels of NO3- measured as nitrogen (above 10 mg/L) are
MA
known to cause a fatal blood disorder called methemoglobinemia in infants [4]. Various techniques for water treatment including adsorption, reverse osmosis, chemical
D
precipitation, ion exchange and electrocatalysis have been employed for treating of NO3-, but
PT E
their application is limited due to incomplete pollutant removal, high energy consumption and toxic sludge production [5]. To overcome these limitations, extensive research has been
CE
focused on developing possible new methods using nanotechnology [6]. A number of studies have focused on the removal of water contaminants using iron
AC
nanoparticles (FeNPs) because iron metal is non-toxic, abundant, cheap and easy to produce. Iron metal has been used for the removal of various water contaminants including chlorinated compounds, pesticides, heavy metals, nitrates and dyes [7, 8]. There are several methods which have been used to synthesize nanoparticles, which include chemical synthesis such as reduction in solutions, sono-chemical methods which is a physical synthetic route, and recently plants have been employed via biological synthesis [9]. The use of plants for synthesis of nanoparticles offers different advantages such as eco-friendliness, non-toxicity 3
ACCEPTED MANUSCRIPT and cost effectiveness [10]. Synthesis of iron oxides nanoparticles have also been reported using various methods in different species for their use as nanomaterial [37]. Lately, leaf extracts of Eucalyptus globules have been used for synthesis of FeNPs and applied in the efficient adsorption of Cr(VI) [11]. The green production of Fe and Fe/Pd bimetallic nanoparticles using green tea extract for reductive degradation of chlorinated
PT
organics has also been reported [12] and results demonstrated that they have effective
RI
removal capability and longevity. Additionally, FeNPs prepared with tea extracts have also
SC
acted as a Fenton catalyst for oxidizing of cationic and anionic dyes and monochlorobenzene [13, 14].
NU
In the present work, green synthetic methods were used to synthesize FeNPs using M. oleifera extracts and applied for the removal of NO3- from surface and groundwater. In
MA
addition, the antibacterial activity of synthesized FeNPs was also investigated against Escherichia coli. E. coli is a faecal coliform that occurs universally in sewage and plays an
D
important role in the sanitary analysis of water, hence why it was chosen for this study. M.
PT E
oleifera is a non-toxic tropical plant found throughout India, Asia, and Sub-Saharan Africa. The plant consists of seeds containing edible oil and a water soluble substance which has
CE
coagulation properties for water treatment [15]. M. oleifera plant has been shown to act as an
[16].
AC
antimicrobial agent against different bacteria and fungi in various water treatment studies
M. oleifera is of interest because as an agent for water treatment is ideal for application in developing countries. Its advantage is that it is not technologically difficult to use by any personnel [17].
4
ACCEPTED MANUSCRIPT 2. Materials and methods 2.1 Materials Iron (III) chloride hexahydrate (FeCl3.6H2O with purity of 99.9%) was purchased from Sigma Aldrich (South Africa); M. oleifera powdered leaves were procured from Garuda
PT
naturals health shop (Pty) Ltd. (South Africa), and M. oleifera seeds were bought from Moringa, South Africa and they were authenticated by Botany section, Biological Science
RI
North West University, Distilled water obtained from the Milli-Q Elga System was used in
SC
all experiments. Nitrate standard solution was obtained from Merck (South Africa).
NU
2.2 Sample preparation
MA
M. oleifera seed (MOS) extract was prepared using a modified batch method. The details of the batch method can be found elsewhere [18, 19]. Briefly, the seeds were separated from
D
the pods and ground into fine powder using a mortar and pestle, followed by oil removal for
PT E
reduction of organic content in aqueous media. The seeds were defatted by mixing the seed powder in 95% ethanol (5%, w/v) and mixed for 30-45 min using a magnetic stirrer. The supernatant liquid was then separated by centrifugation for 45 min at 3000 rpm and the
CE
settled residual was dried at room temperature for 24 hours. From the dried sample; different
AC
concentrations of MOS powder were mixed in 100 mL of 0.1 M sodium chloride and/or distilled water at room temperature using a magnetic stirrer for 60 min and left to settle for 20 min. The M. oleifera crude extract was then filtered through a Whatman filter paper. The filtrate was termed as the crude extract. M. oleifera leaf (MOL) extract was carried out according to the procedure used in Elumalai et al [20]; leaf powder of 4 g was weighed and transferred into 100 mL of distilled water. The mixture was boiled for 20 min at 60 oC; a light yellow solution was formed and 5
ACCEPTED MANUSCRIPT was then cooled at room temperature. After that, the yellow coloured extract was filtered using filter paper and stored in a refrigerator [19]. A green synthesis method was used to prepare nanoparticles according to the modified procedure in Wang et al [21]. For this purpose, M. oleifera extracts of different concentrations were mixed with 0.1 M FeCl3 solution with various volume ratios of 1:1, 1:2,
PT
1:3 and 1:4; and constantly stirred for 30 minutes. A change in colour from faint yellow to
SC
of FeNPs. No filtration or drying of the sample was done.
RI
reddish brown and finally black after a certain known period of time indicated the formation
NU
2.3 Characterizations of nanoparticles 2.3.1 Dynamic light scattering
MA
The average particle size and particle size distribution of the nanoparticles (expressed as polydispersity index, PDI) were determined by using dynamic light scattering (Malvern Zetasizer Nano ZS; Malvern Instrument, Malvern, United Kingdom) at 25 oC. Nanoparticles
D
were filtered by using PTFE 0.2 µL pore size membrane to remove dust particles before
PT E
analysis. All experiments were measured in triplicate.
CE
2.3.2 Particle size distribution
The particle size distribution (expressed as polydispersity index, PDI) was determined
AC
using DLS (Malvern Zetasizer Nano ZS; Malvern Instrument, Malvern, UK) at 25 oC, taking the average of at least three measurements.
6
ACCEPTED MANUSCRIPT 2.3.3 UV-Vis spectroscopy The absorption spectra of FeNPs and M. oleifera extracts were analysed using UV-Visible spectrophotometer (Perkin Elmer, Lambda 35, 54, Singapore). For this purpose, samples were diluted ten times before the study.
PT
2.3.4 X-ray diffraction
RI
To identify the crystallinity phase of nanoparticles formed, X-ray diffraction (XRD)
SC
analysis were performed using Shimadzu 6000 with Cu-Kα radiation source with wavelength of 0.154 nm and was operated at 40Kv/30mA over 2θ range of 2 to 800. The scanning speed
MA
NU
was maintained at 50 min-1.
2.3.5 Fourier transform infrared spectroscopy Fourier Transform Infrared Spectroscopy (FTIR) analysis of FeNPs, MOL and MOS
PT E
D
were done over the range of 4000-400 cm-1. The measurements were carried out on a Cary 600 Series FTIR spectrometer.
CE
2.3.6 Transmission electron microscopy
AC
The morphology of the optimized nanoparticles was analysed using HR-TEM (TEM, JEOL JEM-200, Japan). The nanoparticles were stained with uranyl acetate solution before observation.
7
ACCEPTED MANUSCRIPT 2.3.7 Batch adsorption experiments In order to investigate adsorption of NO3- on FeNPs, MOS and MOL extracts, the modified batch adsorption method of Poguberović et al. [22] was performed under laboratory conditions, on a water bath shaker at a speed of 150 rpm. Adsorption studies were obtained by preparing the required concentration of the nitrate
PT
solution which was achieved by dilution of nitrate stock solution at room temperature. Fixed
RI
amount of FeNPs (0.5 mL) and M. oleifera extracts were added respectively to 10 mL NO3-
SC
solutions containing different initial concentrations in the range of 10–20 mgL-1. The mixture with an initial pH of 2.5 was added into a 20 mL beaker and left to react for 24 hrs. The
NU
reaction mixture was centrifuged for an hour at 3500 rpm and the supernatant liquid was collected. The concentration of the NO3- was then analyzed using a Spectroquant® Prove
MA
Spectrophotometer 300. Uptake of NO3- by nanoparticles, MOS and MOL extracts were
D
calculated using equation (1)
c c c
PT E
% Removal
0
f
*100%
(1)
0
CE
where C0 is the initial metal concentration (mgL-1) and Cf is the final residual concentration of NO3- at the end of the adsorption period, directly measured by the Spectroquant® Prove
AC
Spectrophotometer 300. The obtained NPs were further applied to groundwater and surface water to evaluate the adsorption of NO3- at the same conditions as the prepared nitrate solution.
8
ACCEPTED MANUSCRIPT 2.3.8 Antibacterial activity studies The antibacterial activities of M. oleifera FeNPs and different antibiotics (Ampicillin, Gentamycin, Erytomycin and Vancomycin) were evaluated against Gram negative Escherichia coli (E.coli) O157 obtained from the NWU microbiology research group using the modified paper disc method of Prakash et al., 2013. E. coli is a faecal coliform that occurs
PT
universally in sewage and plays an important role in the sanitary analysis of water. Briefly,
RI
isolates were grown on nutrient agar at 37 °C for 18 to 24 hrs. The bacterial suspensions were
SC
then swabbed on the Mueller-Hinton agar (MHA) plates using sterile cotton swabs. Sterile Whatman No 1 paper discs at 6 mm dimension were impregnated with MOS-FeNPs and
NU
MOL-FeNPs. The discs with different antibiotics (Ampicillin, Gentamycin, Erytomycin and Vancomycin) located on the plates were maintained as references. These discs were gently
MA
pressed in MHA plates and incubated in inverted position for 24 hrs at 37 °C to determine the
PT E
3. Results and discussion
D
zone of inhibition.
3.1 Dynamic light scattering
CE
The average particle size and polydispersity Index results of FeNPs prepared using MOS and MOL are given in Table 1. The results indicated that all the ratios (1:1, 1:2, 1:3, and 1:4)
AC
had an effect on the particle size. The smallest average particle and PDI, for MOS and MOL was obtained with the 1:2 ratios, of 151±2.916 nm and 0.202±0.004 nm, respectively. Possible reasons for size variations include concentration of extract [23], pH alterations leading to agglomeration by over nucleation (at low pH) and instability of nanoparticles (at high pH). MOL was also used in various ratios to fabricate FeNPs. It was observed that the size of the NPs were within a range of 250 - 474 nm (Table 1). The MOL extract produced NPs of appreciable size. Similar ranges in size were also obtained by other researchers [14, 9
ACCEPTED MANUSCRIPT 20]. Further characterization was done on the NPs with the best PDI, because this is a parameter which predicts the heterogeneity of the sample. Therefore, from the above results, nanoparticles formed by ratios of 1:2 and 1:4 were chosen for further analysis because of optimized results, while FeCl3, MOS and MOL were used as controls.
PT
3.2 UV-Vis spectroscopy
RI
UV-Vis spectroscopy is an important technique to establish the formation of
SC
nanoparticles. Figs. 1 and 2 show the UV spectra of MOS and MOL extract, and after reaction with Fe3+. On adding the MOS extract to FeCl3 solution, the mixture changed from
NU
yellow translucent to intense brown, and from greenish to black when using MOL extract. The colour changes are due to the excitation of the surface plasmon resonance in the metal
MA
nanoparticles [24]. An assessment of the UV analysis of MOS-FeNPs and MOL-FeNPs showed absorption peaks in the range of 210 and 240 nm, which are identical to the
D
characteristic UV visible spectrum of metallic iron [22]. The new peak on the MOS-FeNPs
PT E
and MOL-FeNPs was formed at 240 nm. The peak shows the interaction between FeCl3
CE
solution and the M. oleifera extracts.
AC
3.3 FTIR spectroscopy
Infrared spectroscopy was performed to identify the presence of functional groups on the surface of FeNPs, MOS, MOL and FeCl3. Fig. 3 shows three spectra of the MOS extract, FeCl3 solution and the MOS-FeNPs. For MOS a band at 3280 cm-1 is assigned to the O-H stretching vibration and the contribution for the vibration stretching of the N-H bond of the amide group. These bands are due to the protein and fatty acids found in MOS [25].The band at 2918 cm-1 characterizes the band of the C-H bond of the alkane group. The two region 10
ACCEPTED MANUSCRIPT bands at 1615 cm-1 and 1408 cm-1 are attributed to C-O bond stretching. Meanwhile, the FTIR spectra of MOS-FeNPs also displayed stretching vibrations at 3519 cm-1 for O-H, at 1615 cm1
for the C=C and 1049 cm-1 for C-O-C absorption peak [20]. Formation of FeNPs can be
confirmed by a band at 567 cm-1. Similar results were obtained by Luo et al., 2016 for degradation of Orange II using grape leaf aqueous extract to synthesis of bimetallic Fe/Pd
PT
nanoparticles [26].
RI
The FTIR spectra indicated by Fig. 4 showed the bands present at 3412 cm-1, 2362 cm-1 and 1601 cm-1 due to O-H stretching, C-H, and C=O, respectively of MOL-FeNPs. These
SC
regions around 3270 cm-1 (O-H), 2900 cm-1 (C-H) and 1700 cm-1 (C=O) were also observed
NU
on the spectrum of MOL. M. oleifera has been reported to be enriched with phytochemicals such as amino acids, alkaloids, flavonoids and phenolic compounds [27], hence the presence
MA
of these peaks was observed. The peak at 565 cm-1 confirms that FeNPs were obtained.
3.4 X-ray diffraction
D
A powerful tool for showing the crystalline and amorphous region is XRD spectroscopy.
PT E
The XRD patterns of MOS, MOS-FeNPs, MOL and MOL-FeNPs. Presented in Fig. 5 revealed a characteristic peak at around 2θ of 45o on the MOS-FeNPs which corresponds to
CE
zero valent iron [28, 29]. Similar results were observed in recent reports of FeNPs produced by tree leaf extract [28] and green tea [30]. This peak indicates that the green synthesis
AC
produces amorphous NPs [31]. No peaks were observed on the MOL-FeNPs analysis because the peaks of MOL formed at 2θ of around 20o and 25o are due to the high content of oils and proteins within the material’s composition, with a mass of around 69% [32].
11
ACCEPTED MANUSCRIPT 3.5 HRTEM analysis The size and morphology of synthesized FeNPs was analyzed using HRTEM. The HRTEM image (Fig.6a) showed that MOS-FeNPs are spherically shaped with thick surface layer, this could be due to the thickening layer of MOS (Fig. 6b), and the size range was found to be between 2.6 and 6.2 nm while analysis of the MOL-FeNPs by HRTEM confirmed that they
PT
were in nanorange, in spherical shape and a diameter of 3.4 and 7.4 nm. A representative image
SC
spherical shape of FeNPs prepared from Aloe vera [33].
RI
is illustrated in Fig. 7a and 7b. Similar findings were reported by Yadav et al. by describing a
NU
3.6 Adsorption studies
MA
The removal efficiency of NO3- by MOS extract and MOS-FeNPs are presented in Fig. 8. Previous reports have identified application of FeNPs in NO3- removal to be a promising
D
technique [20]. Different concentrations of NO3- (10, 15 and 20 mgL-1) were investigated.
PT E
Dosage (0.5 mL) of different materials was fixed as well as contact time (24 hrs.). The removal of NO3- increased as the pH of the solution decreased respectively with increase in concentration. The MOS-FeNPs were observed to be more effective than the extract. The
CE
removal percentages varied from 69% to 64% respectively. MOL-FeNPs had the highest
AC
NO3- removal efficiency as compared to MOS-FeNPs, with removal efficiency of 76% (Fig.9). The results obtained are almost consistent with previous studies involving NO3reduction using FeNPs [34; 21]. Therefore, regardless the type of FeNPs used, for removal of higher NO3- percentage, a lower pH of aqueous solution must be maintained [5]. The removal of NO3- from surface and ground water using plant extracts and synthesized nanoparticles are presented in Fig. 10. Previous reports have identified application of FeNPs in NO3- removal to be a promising technique [20]. Furthermore, a number of studies have 12
ACCEPTED MANUSCRIPT shown an extensive use of MOS instead of MOL for treating contaminated water [17, 18]. Therefore, the results in Fig.8 revealed the NO3- removal efficiency of MOS, MOS-FeNPs, MOL and MOL-FeNPs. The removal efficiency of NO3- was 43% and 85% for MOS and MOS-FeNPs, respectively whereas 48% and 26% was removed by MOL and MOL-FeNPs, respectively, for ground water. In the case of surface water analysis, 58% and 74% of NO3-
PT
was eliminated when using MOS and MOS-FeNPs, whilst 52% and 70% removal was
RI
achieved by MOL and MOL-FeNPs. Furthermore, MOL-FeNPs achieved 26% of removal of
SC
nitrate present in ground water, and 70% of removal of nitrate present in surf water this could be due low surface area of MOL and the presence of more dissolved solids in groundwater
NU
than surface water.
Wang et al. [21] achieved a percentage removal of 56% and 41%, respectively, using FeNPs
MA
synthesized by green tea and eucalyptus leaves extracts. Based on the above, MOS-FeNPs and MOL-FeNPs with their effective removal ability represent promising alternatives for
PT E
D
NO3- contaminated surface water treatment, and possibly for other types of aqueous media.
3.7 Antibacterial activity
CE
Fig. 11 shows the antibacterial effect MOS-FeNPs, MOL-FeNPs and different antibiotics (Ampicillin, Gentamycin, Erytomycin and Vancomycin) on gram negative strain. Results in
AC
Table 2 shows that MOS-FeNPs (6 mm) is more resistant to E.coli in comparison to MOLFeNPs (5 mm), Ampicillin (10 mm), Gentamycin
(5 mm), Erytomycin (1 mm) and
Vancomycin (0 mm) due to their smaller particle size [35]. The positive charge of Fe ion could be responsible for the antibacterial activity through the attraction between negative charged cell membrane of microorganism [27].
13
ACCEPTED MANUSCRIPT 4. Conclusions Green synthesis of FeNPs using plant extracts is a good alternative to chemical synthesis, since it is pollutant free and eco-friendly. The results obtained in this study confirmed that MOL and MOS extracts can play an important role in the bioreduction of Fe ions to FeNPs. Nitrate removal from aqueous solutions using M. oleifera extracts and FeNPs, exhibited
PT
better effects. The percentage removal of nitrate increased with a decrease in pH. The results
RI
show a possible alternative to the removal of nitrate and also suggest that these NPs have dual
SC
properties of coagulant and antibacterial activities, which is ideal for treating contaminated
NU
water. Further removal of other pollutants is currently under study.
Acknowledgments
AC
CE
PT E
D
MA
This project was funded by National Research Foundation and North West University.
14
ACCEPTED MANUSCRIPT References [1]
I. Ali, Chem. Rev. 112 (2012) 5073-5091.
[2]
K. J. Fatombi, T. A. Ahoyo, O. Nonfodji1, T. Aminou1, J. Water Resource and Protection, 4 (2012) 1001-1008.
[3]
WHO report on drinking water, 2015. WHO fact sheet 2015. available: http://www.who.int/mediacentre/factsheets/fs391/en/. Accessed (20.10.2016) U.S. Environmental Protection Agency. Clean water act analytical methods
PT
[4]
http://www.epa.gov/cwa-methods/approved-cwa-chemical-test-methods (accessed on
[5]
RI
10 July 2017)
M. Kassaee, E. Motamedi, A. Mikhak, R. Rahnemaie, Chem. Eng. J. 166 (2011) 490-
SC
495.
M. Ali, M. Ullah, S. B. A. Hamid, Adv. Mat. Res. 925 (2014) 674-678.
[7]
M. M. Pendergast, E. M. Hoek, Ene. Env. Sci. 4 (2011) 1946-1971.
[8]
A. Ryu, S. W. Jeong, A. Jang, H Choi, Appl. Cata. B: Envir. 105 (2011) 128-135.
[9]
Y. H. Hwang, D. G. Kim, H. S. Shin, J. Haza. Mat. 185 (2011) 1513-1521.
MA
NU
[6]
[10] R. Geethalakshmi, D. Sarada, Int. J. Eng. Sci. Tech. 2 (2010) 970-975. [11] K. Kavitha, S. Baker, D. Rakshith, H.U. Kavitha, R.H.C. Yashwantha, B. P. Harini, S.
D
Satish, Int. Res. J. Bio. Sci. 2 (2013) 66-76.
PT E
[12] V. Madhavi, Mol. Biom. Spect. 116 (2013) 17-25. [13] V. Smuleac, R.Varma. S. Sikdar, D. Bhattacharyya, J. Memb. Sci. 379 (2011) 131137.
CE
[14] Y. Kuang, Q. Wang , Z. Chen , M. Megharaj , R. Naidu, J. Coll. Inter. Sci. 410 (2013) 67-73.
AC
[15] T. Shahwan, S. Abu Sirriah, M. Nairat, E. Boyacı, A. E. Eroglu, T. B. Scott, K. R. Hallam, Chem. Eng. J. 172 (2011) 258-266. [16] C. Y. Yin, Proc. Biochem. 45 (2010) 1437-1444. [17] J. Beltrán‐ Heredia, J. Sánchez‐ Martïn, A. Delgado‐ Regalado, J. Chem. Technol. Biotechnol. (2009) 1653-1659. [18] S. Mangale, S. G. Chonde, A. S. Jadhav, P. D. Raut, J. Nat. Pro. Plant Res. 2 (2012) 89-100. [19] B. Garcia-Fayos, J. M. Arnal, M. Sancho, I. Rodrigo, Desalination and Water Treatment, (2016) 1-8. [20] K. Elumalai, S. Velmurugan, App. Surf. Sci. 345 (2015) 329-336. 15
ACCEPTED MANUSCRIPT [21] T. Wang, J. Lin, Z. Chen, M. Megharaj, R. Naidu, J. Clean Prod. 83 (2014) 413-419. [22] S. S. Poguberović, D. M. Krčmar, S. P. Maletić, Z. Kónya, D. D. T. Pilipović, D. V. Kerkez, S. D. Rončevićet, Ecol. Eng. 90 (2016) 42-49. [23] L. Huang, X. Weng, Z. Chen, M. Megharaj, R. Naidu, Mol. Bio.mol. Spe. 130 (2014) 295-301 [24] H. Y. El-Kassas, A. A. E, Mohamed, S. M. Gharib, Acta Oceanologica Sinica, 38
PT
(2016) 89-98. [25] M. Pattanayak, P. Nayak, J. Nano. Sci. Tech. 2 (2013) 06-09.
[26] D. H. K, Reddy, D. K. V. Ramana, K. Seshaiah, and A. V. R. Reddy, Carbohydrate
RI
Polymers, 88 (2012) 1077-1086.
SC
[27] F. Luo, D. Yang, Z. Chen, M. Megharaj, R. Naidu, J. Haza. Mat. 303 (2016) 145-153. [28] K. Elumalai, S. Velmurugan, S. Ravi, V. Kathiravan, S. Ashokkumar, Spect. Chim.
NU
Acta Part A: Mol. Bio. Spect. 143 ( 2015) 158-164.
[29] A. Truskewycz, R. Shukla, A. S. Ball, J. Env. Chem. Eng. 4 (2016) 4409-4417.
Total. Envir. 533 (2015) 76-81.
MA
[30] S. Machado, J. Pacheco, H. Nouws, J.T. Albergaria, C. Delerue-Matos, Science of the
[31] G. E. Hoag, J. B. Collins, J. L. Holcomb, J. R. Hoag, M. N. Nadagouda, R. S. Varma,
D
J. Mate. Chem. (2009) 19: 8671-8677.
[32] E. C. Njagi, H. Huang, L. Stafford, H. Genuino, H. M. Galindo, J. B. Collins, G. E.
PT E
Hoag, S. L. Suib, Langmuir, 27 (2010) 264-271. [33] C. S. Araújo, Edited by Y. B. Patil, P. Rao, (2013) 225.
7 (2016) 2
CE
[34] Yadav, J., Kumar, S., Budhwar, L., Yadav, A. and Yadav, M, J. Nanomed. Nanotech.
[35] Y. Liu, S. Li, Z. Chen, M. Megharaj, R. Naidu, Paracoccus sp, Chemosphere, 108
AC
(2014) 426-432.
[36] C. Carlson, S. M. Hussein, A. M. Schrand, L. K. Braydich-Stolle, K. L.Hess, R. L. Jones, J. J. Schlager, J. Phys. Chem. B, 112 (2008) 13608-13619. [37] W. Wu, Z. Wu, T. Yu , C. Jiang, W. Kim, Sci. Technol. Adv. Mater. 16 (2015) 023501.
16
ACCEPTED MANUSCRIPT Table 1: Size and PDI of synthesized FeNPs from MOS and MOL extracts.
MOS ratios Particle size (nm)
PDI
224±62.31
0.459±0.173
1:2
151±2.916
0.202±0.004
1:3
211±2.858
0.373±0.017
1:4
138±4.565
0.219±0.001
RI
PT
1:1
SC
MOL ratios 306.5±9.263
0.677±0.103
1:2
250.1±7.211
0.763±0.035
1:3
474.9±8.045
0.571±0.010
MA
NU
1:1
273.9±1.856
AC
CE
PT E
D
1:4
17
0.441±0.010
ACCEPTED MANUSCRIPT Table 2: Zone of inhibition images of MOS-FeNPs, MOL-FeNPs and different antibiotics (Ampicillin, Gentamycin, Erytomycin and Vancomycin) against E. coli.
15
MOS-FeNPs
17
Ampicillin
5
Gentamycin
10
Erytomycin
1
SC
MOL-FeNPs
PT
Zone of inhibition (mm)
RI
Components
0
AC
CE
PT E
D
MA
NU
Vancomycin
18
ACCEPTED MANUSCRIPT
5.5
MOL extract FeCl3.6H2O MOL-FeNPs
5.0 4.5 4.0
3.0 2.5 2.0
PT
Absorbance
3.5
1.5 1.0
RI
0.5 0.0
200
300
400
500
SC
-0.5
600
700
800
NU
Wavenumber (nm)
AC
CE
PT E
D
MA
Fig. 1: UV-visible absorption peak of MOL extract, MOL-FeNPs and FeCl3.
19
ACCEPTED MANUSCRIPT
6
5
FeCl3.6H2.O MOS extract MOS-FeNPs
3
PT
Absorbance
4
RI
2
0 300
400
500
600
700
800
NU
200
SC
1
MA
Wavenumber (nm)
AC
CE
PT E
D
Fig. 2: UV-visible absorption peak of MOS extract, MOS-FeNPs and FeCl3.
20
SC
RI
PT
ACCEPTED MANUSCRIPT
-1
NU
(cm )
AC
CE
PT E
D
MA
Fig. 3: FTIR spectra of MOS-FeNPs, MOS extract and FeCl3 solution.
21
MA
NU
SC
RI
PT
ACCEPTED MANUSCRIPT
-1
(cm )
AC
CE
PT E
D
Fig. 4: FTIR spectra of MOL-FeNPs, MOL extract and FeCl3 solution.
22
ACCEPTED MANUSCRIPT
2500
Moringa oleifera seeds MOS-FeNPs 2000
Counts
1500
PT
1000
SC
RI
500
0 0
20
40
60
80
100
120
NU
Position 2()
MA
1200
1000
D PT E
600
200
0
CE
400
AC
Counts
800
Moringa oleifera leaves MOL-FeNPs
0
20
40
60
80
100
Position 2()
Fig. 5: XRD pattern of MOS, MOS-FeNPs, MOL and MOL-FeNPs
23
120
ACCEPTED MANUSCRIPT
MA
NU
SC
RI
PT
a
AC
CE
PT E
D
b
Fig 6: HRTEM images of (a) MOS and (b) MOS-FeNPs
24
ACCEPTED MANUSCRIPT
MA
NU
SC
RI
PT
a
AC
CE
PT E
D
b
Fig 7: HRTEM images of (a) MOL and (b) MOL-FeNPs
25
NU
SC
RI
PT
ACCEPTED MANUSCRIPT
AC
CE
PT E
D
MA
Fig 8: Removal of NO3- using MOS extract and MOS-FeNPs
26
MA
NU
SC
RI
PT
ACCEPTED MANUSCRIPT
AC
CE
PT E
D
Fig 9: Removal of NO3- using MOL extract and MOL-FeNPs
27
MA
NU
SC
RI
PT
ACCEPTED MANUSCRIPT
Fig 10: Effectiveness of plant extracts and synthesized nanoparticles on real sample
AC
CE
PT E
D
application.
28
SC
RI
PT
ACCEPTED MANUSCRIPT
NU
Fig 11: Zone inhibition of MOS-FeNPs, MOL-FeNPs and different antibiotics (Ampicillin,
AC
CE
PT E
D
MA
Gentamycin, Erytomycin and Vancomycin) against E. coli.
29
ACCEPTED MANUSCRIPT Highlights Green synthesis of iron nanoparticles (FeNPs) were prepared. The removal of nitrate from surface and ground water were performed.
AC
CE
PT E
D
MA
NU
SC
RI
PT
The antibacterial activities were evaluated against Escherichia coli (E.coli).
30
