XIV
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International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
289
T5: P–9
Dyes in cellulose-based sorbends for water pollutants abatement –
identification and differentiation based on Raman spectroscopy
Damian K. Chlebda
1
, Tomasz Łojewski
2
, and Joanna Łojewska
1
1
Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Kraków, Poland,
e-mail: damian.chlebda@uj.edu.pl
2
Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Al.
Mickiewicza 30, 30-059 Kraków, Poland
Over the past decade, novel and cheap adsorbents dedicated to removing impurities from
aqueous solutions have been attracting scientific attention. Some of the studies focus on
exploiting waste plant materials such as leaves, wood chips, grain husks, straw, banana pith, and
corncobs [1, 2]. Researchers and technologists accustomed to classic adsorbents received new
and surprising materials worthy of a broader investigation.
Research concerning low-cost adsorbents mainly focuses on searching for and testing
materials to be used for the sorption of water contaminants such as heavy metal ions, or aliphatic
and aromatic hydrocarbons (pesticides, dyes, phenols, pyrene, etc.). Among this group – dyes
are used widely in the paper, textile, rubber, plastics and cosmetics industry. The number of
dyes produced every year reaches above 7105 tons and the number of its different forms/colors
exceeds 100 thousand that are available in the market [3]. Various techniques are used to
remove dyes from wastewater and include adsorption, nanofiltration, coagulation, advanced
chemical and electrochemical methods, application of different types of membranes as well as
biological processes. Thus biodegradability of those types of contaminants are low, the process
that utilize the bio-based methods like activated sludge process or biological contractors are not
effective enough to remove them from the water. Till now adsorption is one of the most efficient
methods of dye wastewater treatment due to its low initial costs, the simplicity of equipment,
easy operation of equipment and resistance to toxic substances.
A particular aim of this study was to elaborate the method of identification of selected dyes
adsorbed in low-cost cellulosic sorbents. The analysis is based on the Raman microscopy aided
with chemometric analysis. The plant-based sorbents are gaining more importance as an
alternative material for the removal of organic and inorganic contaminants from wastewater.
Identification of the dyes can help with the problem of selection of suitable sorbent for removal
of toxic dyes from water. Information from Raman spectra was correlated with the sorption
capacity of particular synthetic dyes: Reactive Blue 81, Reactive Red 120, Direct Black 22 and
Direct Orange 26 to the ecological plant-based sorbents. The classification results from principal
component analysis and hierarchical cluster analysis clearly show that information from Raman
spectroscopy can be enhanced with chemometric analysis and simplify the differentiation of
dyes.
Keywords: Raman spectroscopy, principal component analysis, dyes, water pollutants
Acknowledgment
Financial support for this work was provided by the National Science Centre, Poland – project no.
2015/19/N/ST8/00181
References
[1] V.K. Gupta, P.J.M. Carrott, M.M.L. Ribeiro Carrott, Crit. Rev. Environ. Sci. Technol. 39 (2009) 783.
[2] D. Sud, G. Mahajan, M.P. Kaur, Bioresour. Technol. 99 (2008) 6017.
[3] X.S. Wang, Y. Zhou, Y. Jiang, C. Sun, J. Hazard. Mater. 157 (2008) 374.
XIV
h
International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
290
T5: P–10
Raman spectroscopic studies of high-Mn-enriched apatite-supergroup
minerals from the Szklary pegmatite (Lower Silesia, Poland)
Bożena Gołębiowska
1
, Piotr Jeleń
2
, Adam Pieczka
1
, Magdalena-Dumańska Słowik
1
,
Maciej Sitarz
2
, Mariola Marszałek
1
, Adam Szuszkiewicz
3
, and Eligiusz Szełęg
4
1
AGH University of Science and Technology, Department of Mineralogy, Petrography and Geochemistry,
30-059 Kraków, Mickiewicza 30, Poland; e-mail: goleb@agh.edu.pl
2
AGH University of Science and Technology, Faculty of Materials Science and Ceramics, 30-059 Kraków,
Mickiewicza 30, Poland
3
University of Wrocław, Institute of Geological Sciences, 50-204 Wrocław, pl. M. Borna 9, Poland
4
University of Silesia, Faculty of Earth Sciences, Department of Geochemistry, Mineralogy and
Petrography, 41-200 Sosnowiec, Będzińska 60, Poland
Pieczkaite, (Mn,Cl)-dominant analogue of apatite [1] with an extreme composition of
(Mn
4.27
Ca
0.52
Fe
0.19
)
Σ4.98
(PO
4
)
3
(Cl
0.78
OH
0.22
)
Σ1.00
, and a pieczkaite-like phase (Mn < 2.5 Mn apfu and/or Cl <
0.5 apfu) of (Ca
2.68
Mn
2.17
Fe
2+
0.10
Fe
3+
0.01
Mg
0.01
K
0.02
)
Σ4.99
(PO
4
)
3
(Cl
0.37
OH
0.52
F
0.11
)
Σ1.00
, respectively, occur as
inclusions with sizes from 10 to 200 μm in larger crystals of hydroxy- to fluorapatites, beusites and
muscovite in the Szklary granitic pegmatite. Locally they are associated with bobfergusonite and fillowite,
and most often are surrounded by secondary Mn-oxide – smectite aggregates. It is supposed that both Mn-
bearing phosphates crystallized under the influence of Mn-, Cl-, and OH-bearing fluids simultaneously with
or after beusite formation, and then were replaced by hydroxy- to fluorapatite or completely altered to Mn
oxides.
The aim of the study was to provide the detailed Raman spectroscopy characteristics of
compositionally-varied pieczkaite crystals and the pieczkaite-like phase, mostly differing in
Mn*/(Mn*+Ca*) ratio (0.50–0.90), where Mn*=Mn+Fe and Ca*=Ca+Sr, and Cl (0.37–0.84 apfu). Raman
spectra were collected at ambient conditions, using a Horiba Labram HR spectrometer equipped with a laser
Nd: YAG, 532 nm (10 mW), grating 1800 gr/mm and an Olympus BX 40 confocal microscope. The spectra
were recorded in backscatter geometry in the range 4000–50 cm
−1
with a resolution of 0.5 cm
−1
; collection
times of 600 s and accumulations of 2 scans were chosen. The RS spectra were recorded for the spots,
analysed previously with an electron microprobe.
As a result, a characteristic set of two strong bands around 960–940 and 1020–1005 cm
−1
due to
phosphate PO
4
3−
symmetric and antisymmetric stretching vibrations (ν
1
and ν
3
mode), respectively, were
observed. Other Raman bands around 650–500 (ν
4
) and 440–420 (ν
2
) cm
−1
are attributed to PO
4
3−
bending
modes. The bands in the region above 3200 cm
−1
are assigned to water stretching vibrations. In the region
below 400 cm
−1
the bands are due to O-metal and external or lattice vibrations [2].
The Raman spectra of pieczkaite from Szklary with the highest amounts of Mn, corresponding to
Mn*/(Mn*+Ca*)=0.90, exhibit strong P–O stretching bands at 943 (ν
1
) and 1007 cm
−1
(ν
3
). A crystal with
lower Mn*/(Mn*+Ca*)=0.57 reveals strongest bands at 952 and 1015 cm
−1
. The lowest content of Mn and
the highest degree of substitution by Ca in a crystal of pieczkaite-like phase with Mn/(Mn+Ca)=0.50 and Cl
< 0.50 apfu, is responsible for the shift of ν
1
and ν
3
bands towards even higher wavenumbers, i.e. at 955 and
1016 cm
−1
. We conclude that the bands position of the PO
4
3−
stretching vibrations in pieczkaite and
pieczkaite-like phase is a function of crystal structure of the phosphates [3]. The observed differences seem
to be attributed to quantitative relationship between Ca* and Mn* occupying the M1 and M2 sites in the
apatite structure and variations in atomic weight between these elements. The increasing amounts of Ca
with lower atomic weight than Mn and Fe shifts ν
1
and ν
3
bands of the Mn-bearing phosphates toward
higher wavenumbers. This may indicate that the studied compositions can be a simple solid solution
between pieczkaite Mn
5
(PO
4
)
3
Cl and hydroxyapatite Ca
5
(PO
4
)
3
OH.
Keywords: pieczkaite; Raman spectroscopy; chemical composition; Szklary; Poland
Acknowledgment
The work was financially supported by the National Science Centre (Poland) grant 2015/17/B/ST10/03231 to AP
and AGH UST grant 11.11.140.319.
References
[1] K. Tait, N.A. Ball, F.C. Hawthorne, Am. Mineral. 100 (2015) 1047.
[2] R.L. Frost, Y. Xi, R. Scholz, A. López, F.M. Belotti, Vib.rational Spectrosc. 66 (2013) 69.
[4] V.C. Farmer, The Infrared Spectra of Minerals, Monograph 4, 1st ed., Mineralogical Society, London, 1974.
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