CHEMICAL ENGINEERING TRANSACTIONS
VOL. 56, 2017
A publication of
The Italian Association
of Chemical Engineering
Online at www.aidic.it/cet
Guest Editors: Jiří Jaromír Klemeš, Peng Yen Liew, Wai Shin Ho, Jeng Shiun Lim
Copyright © 2017, AIDIC Servizi S.r.l.,
ISBN 978-88-95608-47-1; ISSN 2283-9216
Effect of Zeolite 4A to Marine Microalgae Culture
Afifi Zainal*, Liyana Yahya, Muhammad N. Chik, Nur K. Hussien, Mohd H. Boosroh
Renewable Energy & Green Technology Unit, TNB Research Sdn. Bhd, No. 1, Lorong Ayer Itam, Kawasan Institusi
Penyelidikan Bangi, 43000 Kajang, MALAYSIA
afifi.zainal@tnbr.com.my
As a photosynthetic organism, microalgae curbs carbon dioxide (CO2) emission via carbon up-take either in
active or passive transport trough it cell wall. Nonetheless, the bottleneck factor of CO2 fixation trough
microalgae is due to CO2 dissolution in water. Apart from the dissolution of CO2 from air into water is too slow
to replace the assimilated CO2 by microalgae, the solubility of CO2 in water decreases with increasing of salinity.
Hence this paper describes the initiative using nanomaterial to increase the dissolution of CO2 in marine
microalgae culture. Marine microalgae culture has been inoculated in 10 liter photobioreactor (PBR). The
ambient temperature has been set at 25 °C and in 12 h / 12 h dark-light photoperiod. 10 g of zeolites 4a as
nanomaterial has been used to increase the dissolution of CO2 in the saline cultured solution. Through this
study, growth rate for culture added with zeolite was µZ4A was 0.35 O.D.day-1, and cell doubling time Td-Z4A was
1.96 day. In contrast the control culture growth rate µcontrol was 0.22 O.D.day-1, and for cell doubling times Td-
control it takes 3.15 day. The highest concentration of inorganic carbon in solution in microalgae culture with zeolite
was 23.3 ppm while the control culture was only 15.4 ppm. Thus proof that zeolite 4A hastens the dissolution of
CO2 in marine microalgae culture, therefore enhancing carbon capture trough biological means.
1. Introduction
Microalgae, a photosynthetic organism assemblage required light, CO2 and nutrient to growth (Razzak, et al.,
2013). Most commonly microalgae can be found water, be it fresh water, marine, or brackish. However, they
can also be found in almost every other environment on earth (Lee, 2008). The algal biomass is seen as an
alternative for a sustainable diversified feedstock to various industries either for energy, food, fine chemical
industry (Harun et al., 2014) or agriculture and aquaculture feeds (Yaakob et al., 2014). Thus, apart from
intended for harvesting its high potential biomass, it is beneficial if the mass culturing facilities to be run in parallel
for mitigating carbon emission. Microalgae culturing as the instrument for mitigating anthropogenic carbon
dioxide (CO2) has been well received among researcher, furthermore this endeavour envisage a new pathways
for microalgae biomass valorisation (Van Den Hende et al., 2012). Recent findings from National Oceanic and
Atmospheric Administration (NOAA) shows that on year 2015, CO2 concentration in the atmosphere has already
hit the records, achieving beyond 400 ppm (Dlugokencky and Tans, 2015). In Malaysia land transport combine
with CO2 extensive industries such as oil & gas, palm oil, energy sectors are expected to contribute 86 % of
total CO2 emission in 2020 (Harris, 2012). These CO2 extensive industries generated about 5 – 20 % of CO2
from its flue gas thus offer better mitigation potential, with commensurate increase in algal biomass production
(Brennan and Owende, 2013). Hence, by implementing microalgae biotechnology for capturing and utilized
inorganic carbon waste from industrial flue gas, high yield and valuable algal biomass can be produced.
1.1 Phycoremediation for carbon capture technology
Phycoremediation, a process whereby microalgae being used for biotreatment either for waste water treatment
especially on nutrient removal process (Olguin, 2003), domestic sewerage, (Rawat et al., 2010), industrial
effluent (Zainal et al., 2012) or to be used as parts of carbon captures for industrial flue gas treatment (Yen et
al., 2015). Though phycoremediation for nutrient and organic removal has been well received among researcher
(Colla et al., 2010; Rao et al., 2011), more research development is needed in area of carbon capture through
microalgae. One of the bottle neck issues in carbon capture through microalgae is due to slow dissolution of
DOI: 10.3303/CET1756082
Please cite this article as: Zainal A., Yahya L., Chik M.N., Hussien N.K., Boosroh M.H., 2017, Effect of zeolite 4a to marine microalgae culture,
Chemical Engineering Transactions, 56, 487-492 DOI:10.3303/CET1756082
487
CO2. When CO2 dissolves in an aqueous medium, it reacts through a set of chemical equilibriums which mainly
consist of species of CO2, carbonate, bicarbonate and carbonic acid. (Van Den Hende et al., 2012). Upon
achieving equilibrium, the hydration process of CO2 in the water took longer time. Consequently, the available
dissolve inorganic carbon from CO2 gas was too slow to be ready to replace the assimilated carbon by
microalgae. Therefore this situation leads to some CO2 freely escape to the atmosphere during the cultivation
process. In addition, the solubility of CO2 in water decreases with increasing of salinity, thus less CO2 retained
in the solution cultured with marine microalgae (Markou et al., 2014).
1.2 The way forward
In carbon capture technology, incorporating nanomaterial and zeolite in the membrane layer matrix as parts of
separation process has gained much attention such as in inorganic microporous membrane (Li et al., 2015),
MFI membrane (Sjöberg et al., 2015), modified nanoporous silica (González-barriuso et al., 2016) and novel
porous solid (Puccini et al., 2016). Although research development on phycoremediation incorporating zeolite
and nanomaterial with microalgae culture is still new, there is an attempt of using zeolite as nutrient removal in
microalgae culturing. Study reveal that zeolite may influence microalgae yield in marine microalgae due to
changes in culture medium (Fachini et al., 2004), whereas zeolite too has been study as parts of biofilm rotating
photobioreactor for nutrient removal through phycoremediation (Young, 2011), while hydrogel has been used to
immobilized microalgae for environmental application (González-delgado et al., 2016). Hence, this paper
describes the preliminary study towards overcoming slow CO2 dissolution by incorporating zeolite as catalyst
as well as adsorbent in the marine microalgae culture. The aim of this article is to evaluate the potential of zeolite
4A in improving CO2 dissolution reactivity in marine microalgae culture, therefore assisting microalgae to fixed
CO2 as well as improved its growth.
2. Materials and methodology
2.1 Microalgae strains
A consortium of native marine microalgae species were used in these experiments. The native species consists
of Chlorella sorokiniana (NCBI KR869729), Chlorella pyrenoidosa (NCBI KT852374), and Amphora sp. The
consortia was isolated from the sea water outfall at Sultan Azlan Shah Power Station, Manjung Perak at west
coast of Malaysia Peninsular, 4° 9’ 31.158”S latitude and 100° 38’ 30.3396” E longitude. The initial inoculum
was set at 0.4 optical density (O.D) at 560 nm absorbance. In addition TNBR medium (Yahya et al. 2015) and
artificial saline water, Red Sea Salt (Houston, USA) were used as a growth solution for the microalgae.
2.2 CO2 dissolution
The dissolution of CO2 was determined through inorganic carbon (IC) analysis, General Electric InnovOx
Analyzer (Colorado, United States). In this study nanomaterial zeolite type 4A was used to enhance CO2
dissolution on marine microalgae culture. To verify Zeolite 4A capacity in enhancing dissolution of CO2 in saline
water, a setup of 1 L column filled with artificial saline water, Red Sea Salt (Houston, USA) was added with 10
g of zeolite 4A. The saline water solution was aerated via aeration pump and purged intermittently with CO2 that
being regulated by pH controller at pH range 6.3 – 7.0. Simultaneously, a blank setup without zeolite 4A was
run as a control parameter. The IC concentration obtained versus time for both setup was then plotted in a
graph.
2.3 Materials and procedures
Microalgae were cultured in 10 L laboratory photobioreactor as shown in figure 1. In this study, 10 g zeolite 4A,
Sigma Aldrich (Missouri, USA) was put in a sack and affixed directly to the air sparger at the bottom of PBR
column. In addition, a similar setup of marine microalgae culture without addition of zeolite 4A was run as a
control medium.
The effect of zeolite 4A towards microalgae growth was observed trough optical density using HACH DR2800
Spectrometer (Colorado, USA) at 560 nm absorbance. Microalgae growth curved was plot hence, the specific
growth rate µ, was calculated according to Eq. (1) where N1 and N2 represent the optical density at time T1 and
T2 respectively.
Growth rate, µ = ln(N2/N1)/(T2−T1) (1)
While the cell doubling time Td, was calculated according to Eq. (2) where µ represent specific growth rate.
Doubling time Td = ln 2/µ (2)
The ambient temperature for the experiment was fixed at 25 oC (± 2 oC) and in 12 h / 12 h dark-light photoperiod.
Culture was aerated with air and pure CO2 (99 %) was influx intermittently and been regulate by PINPOINT pH
488
controller, American Marine Inc., (Ridgefield, USA) at range pH 6 to 7. The experiment was run in duplicate for
a period of seven consecutive days.
Figure 1: Two set of 10 L laboratory photobioreactor setup
3. Result and Discussion
3.1 Zeolite 4A as CO2 dissolution enhancer
Initial study on effect of zeolite 4A to the dissolution of CO2 was conducted on artificial seawater. CO2 dissolution
was observed through concentration level of inorganic carbon. Based from Figure 2 it is certain that zeolite 4A
helps to retained CO2 in artificial seawater water. It was observed that maximum IC concentration in blank
artificial seawater solution was 27.3 ppm. In parallel the artificial seawater solution that contained zeolite 4A has
higher IC concentration at 44.4 ppm.
Figure 2: Concentration of inorganic carbon (IC) in artificial seawater
The result shows that zeolite 4A has hastened the time required to increase IC concentration. These can be
seen in Figure 2 which illustrates that between first initial two days the IC in the saline solution added with zeolite
4A has increase remarkably compared to the blank solution. Due to zeolite 4A has approximate pore diameter
0
10
20
30
40
50
0 1 2 3 4 5 6
In
o
rg
a
n
ic
C
a
rb
o
n
(
p
p
m
)
Days
IC blank IC zeolite
489
of 4 Å, it capable to adsorb CO2 trough it molecular sieve (Hauchhum and Mahanta, 2014; Myers and Sircar,
2003). Zeolite 4A helps to prolong the retention time of CO2 in the solution, in parallel it act as catalyst to speed
up the reaction of CO2 into form of ion (Myers and Sircar, 2003). As such Zeolite 4A accelerate CO2 dissolution
process and resulted more dissolve inorganic carbon available in the saline solution thus less CO2 gas escape
to the atmosphere.
3.2 Zeolite 4A effect on algae growth and inorganic carbon in microalgae culture
In Figure 3 it shows that microalgae thrive better with addition of zeolite 4A. The algae growth was observed
through light absorbance at 560 nm optical density whereas the CO2 dissolution was observed through inorganic
carbon. After one week of culturing and aerated with pure CO2 and air, the optical density for microalgae algae
culture added with zeolite has increase from 0.4 OD to 0.915 OD, while the maximum OD for control culture
only achieved 0.533 OD. Based from Eq(1) and Eq(2), growth rate for culture added with zeolite was µz(day1-2)
was 0.35 O.D / d, and cell doubling time Tdz was 1.96 day. In contrast the control culture growth rate µc(day5-6)
was 0.22 O.D / d, and for cell doubling times Tdc it takes 3.15 day.
Figure 3: Zeolite 4A effect towards optical density and Inorganic carbon
From Figure 3 it can be seen after two days of culturing, it shows that there’s step increase of IC in microalgae
culture added with zeolite 4A with concentration of 23.3 ppm before it starts to gradually decreased. This can
be understood as in the initial stage of microalgae culturing, the concentration of microalgae cell is lesser, as
such amount of CO2 added in the PBR supersede the CO2 uptakes by the microalgae. However when algae
starts to grow and the concentration of microalgae cell gets higher, the IC concentration shows a decreasing
trend as capacity of CO2 uptake from microalgae cell gets higher (Lam, et al., 2012). Meanwhile, though the
control experiment gave nearly similar trend of IC in the initial stage, the magnitude of IC concentration in the
microalgae culture is lesser due to more low mass transfer rates of CO2 to the water cause CO2 escape to the
air (Pires, et al., 2012) thus leads to low performance in algae growth. This can be co-relating with low OD,
which indicates low microalgae growth when compared to the culture added with zeolite 4A.
4. Conclusions
Throughout this study, the addition of nanomaterial Zeolite 4A helps to increase dissolves CO2 in terms of
available inorganic carbon in microalgae culture. Addition of zeolite in the culture has assist the reaction process
for CO2 gas dissociates to the form of ion, thus stay longer in the microalgae culture. Furthermore through this
0
5
10
15
20
25
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0 1 2 3 4 5 6 7
In
o
rg
a
n
ic
C
a
rb
o
n
(
p
p
m
)
O
p
ti
ca
l
d
e
n
si
ty
@
5
6
0
n
m
OD control OD zeolite IC control IC zeolite
490
study zeolite 4A shows no adverse effect to microalgae growth and in parallel it shows that better microalgae
growth with addition of zeolite 4A compared to the control experiment. This phenomenon indicates that limitation
issue of available dissolve CO2 in microalgae culture that hinder the growth performance of microalgae are now
able to be unlocked with the addition of nanomaterial, Zeolite 4A. This finding has leads to an improvised
culturing method in utilizing algal biotechnology as instrument for CO2 capture and utilization. Thorough research
should be conduct in future, especially in the area zeolite selectivity that performs better in the sorption of CO 2
as well as able to synergized algae growth.
Acknowledgments
The authors would like to thank TNB Research Technical Board Committee for approving a seeding fund no.
TNBR / SF0180/2015 in supporting the research on carbon capture, utilization and storage using biological
approach.
Reference
Brennan L., Owende P., 2013. Biofuel from from Microalgae: Towards Meeting Advanced Fuel Standards, Ed.
Lee J.W., Advanced Biofuel and Bioproducts, Volume 2, New York, Springer, 533–599.
Colla L.M., Saggiorato A.G., Siebert R., Tatsch P.O., Hemkemeier M., Costa J.A.V., Bertolin T.E., 2010,
Cultivation of microalgae Spirulina platensis (Arthrospira platensis) from biological treatment of swine
wastewater. Ciênc. Tecnol. Aliment., Campinas 30 (1), 173-178,.
Dlugokencky E., Tans P., 2015, Recent global monthly mean CO2. NOAA/ESRL. accessed 24.06.2016
Fachini A., Leal M.F.C., Vasconcelos M.T.S.D., 2004, Are zeolites capable of modifying the yield of marine
micro-algae cultures? a case study with Emiliania huxleyi and a product of zeolitic nature, Aquaculture 237
(1–4), 407–419.
González-barriuso M., Gómez L., Pesquera C., Perdigón A., 2016, CO2 Capture at Low Temperature by
Nanoporous Silica Modified with Amine Groups, Chemical Engineering Transactions 47, 181–186.
González-delgado Á.D., Barajas-solano A.F., Yolima Y., 2016. Microalgae Immobilization Using Hydrogels for
Environmental Applications : Study of Transient Photopolymerization, Chemical Engineering Transactions
47, 457–462.
Harris S., 2012, Opportunities and Risks Arising from Climate Change for Malaysia, Khazanah Nasional,
accessed 24.06.2016.
Harun R., Singh M., Forde G.M., Danquah M.K., 2010, Bioprocess engineering of microalgae to produce a
variety of consumer products, Renewable and Sustainable Energy Reviews 14 (3), 1037–1047.
Hauchhum L., Mahanta P., 2014, Carbon dioxide adsorption on zeolites and activated carbon by pressure swing
adsorption in a fixed bed, International Journal of Energy and Environmental Engineering 5 (4), 349–356.
Van Den Hende S., Vervaeren H., Boon N., 2012, Flue gas compounds and microalgae: (Bio-)chemical
interactions leading to biotechnological opportunities, Biotechnology Advances 30 (6), 1405–1424.
Lam M.K., Lee K.T., Mohamed A.R., 2012, Current status and challenges on microalgae-based carbon capture,
International Journal of Greenhouse Gas Control 10, 456–469.
Lee R.E., 2008. Phycology Fourth Edition, Colorado State University, Cambridge University Press, Cambridge
UK.
Li H., Haas-Santo K., Schygulla U., Dittmeyer R., 2015, Inorganic microporous membranes for H2 and CO2
separation—Review of experimental and modeling progress, Chemical Engineering Science 127, 401–417.
Markou G., Vandamme D., Muylaert K., 2014, Microalgal and cyanobacterial cultivation: The supply of nutrients,
Water Research 65, 186–202.
Myers A.L., Sircar S., 2003, Gas Separation by Zeolites, Handbook of Zeolite Science and Technology, CRC
Press, Florida, US.
Olguin E.J., 2003. Phycoremediation : key issues for cost-effective nutrient removal processes, Biotechnology
Advances 22, 81–91.
Pires J.C.M., Alvim-Ferraz M.C.M., Martins F.G., Simões M., 2012, Carbon dioxide capture from flue gases
using microalgae: Engineering aspects and biorefinery concept, Renewable and Sustainable Energy
Reviews 16 (5), 3043–3053.
Puccini M., Stefanelli E., Seggiani M., Vitolo S., 2016, Removal of CO2 from Flue Gas at High Temperature
Using Novel Porous Solids, Chemical Engineering Transactions 47, 139–144.
Rao P.H., Kumar R.R., Raghavan B.G., Subramanian V.V., Sivasubramanian V., 2011, Application of
phycoremediation technology in the treatment of wastewater from a leather-processing chemical
manufacturing facility, Water SA 37 (1), 7–14.
Rawat I., Ranjith Kumar R., Mutanda T., Bux F., 2010, Dual role of microalgae: Phycoremediation of domestic
wastewater and biomass production for sustainable biofuels production, Applied Energy 88 (10), 3411–3424.
Razzak S.A., Hossain M.M., Lucky R.A., Bassi A.S., De Lasa H., 2013, Integrated CO2 capture, wastewater
treatment and biofuel production by microalgae culturing - A review, Renewable and Sustainable Energy
491
Reviews 27, 622–653.
Sjöberg E., Barnes S., Korelskiy D., Hedlund J., 2015, MFI membranes for separation of carbon dioxide from
synthesis gas at high pressures, Journal of Membrane Science 486, 132–137.
Yaakob Z., Ali E., Zainal A., Mohamad M., Takriff M.S., 2014. An overview: biomolecules from microalgae for
animal feed and aquaculture, Journal of Biological Research-Thessaloniki 21, 6, DOI:10.1186/2241-5793-
21-6
Yahya L., Chik M.N., Harun I., Boosroh M.H., Radzun K.A., Sulong A., 2015, Formulation and testing of an
improved nutrient for Isochrysis sp. culture at a live coal-fired power plant, International Conference on
Environment 2015 (ICENV 2015), Penang, Malaysia.
Yen H.W., Ho S.H., Chen C.Y., Chang J.S., 2015, CO2, NOx and SOx removal from flue gas via microalgae
cultivation: A critical review, Biotechnology Journal 10 (6), 829–839.
Young A.M., 2011. Zeolite-based Algae Biofilm Rotating Photobioreactor for Algae and Biomass Production.
MSc. Thesis, Utah State University, Utah, United States of America.
Zainal A., Yaakob Z., Takriff M.S., Rajkumar R., Ghani J.A., 2012, Phycoremediation in Anaerobically Digested
Palm Oil Mill Effluent Using Cyanobacterium, Spirulina platensis, Journal of Biobased Materials and
Bioenergy, 6, 1–6.
492