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PHYTOREMEDIATING POTENTIALS OF Sida acuta and Duranta erecta FOR LEAD, CADMIUM, COBALT AND ZINC

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Abstract

Recently pollution of the environment has gathered an increased global interest. In this respect, contamination of soils with heavy metals has always been considered a critical challenge in the scientific community . Remediation of soil contaminated by heavy metals is necessary in order to reduce the associated risks, make the land resource available for agricultural production, enhance food security, and scale down land tenure problems. Immobilization, soil washing, and phytoremediation are frequently listed among the best available technologies for cleaning up heavy metal contaminated soils but have been mostly demonstrated in developed countries. Nonedible African plants –Sida acuta and Duranta erecta were used to study the absorption of Cadmium, Lead Zinc and Cobalt from soils inoculated with the metal ions. 0.1M, 0.5M and 1M solutions of the metal ions were used in the inoculation. The Leaves, stems and roots of Sida acuta and the stems and roots of Duranta erecta were collected in the first instance at six weeks, and then, at ten weeks of planting. Atomic Absorption Spectrophotometer was used to determine the metal ion concentration in the plants’ parts. Lead was more absorbed by Sida acuta than did Duranta erecta, with the highest absorption of 1.223mg/kg in the former occurring in the roots. Absorption increased as the concentration of the inoculant solution increased, and also on moving from 6 weeks’ to 10 weeks’ samples for concentrations less than 0.1M. Cadmium was the only absorbed by Sida acuta, with a highest value of 6.495mg/kg in the roots,. Duranta erecta was poisoned by Cd2+ in all concentrations. Zinc was more absorbed by Duranta erecta than did Sida acuta, with the highest absorption of 7.898mg/kg in the former occurring in stems. Absorption increased as the concentration of the inoculants solution increased. Cobalt was most absorbed by Sida acuta with the highest value of 9.354mg/kg found in the stem. Generally, Phytotoxicity was shown in the plants at inoculants concentration above 0.5M, after 6 weeks except for Duranta erecta inoculated with Zn2+. The tolerance for Lead, Cadmium, and Cobalt by Sida acuta show a good promise for its phytoremediation and recovery.
International Journal of Science and Research (IJSR)
ISSN: 2319-7064
Index Copernicus Value (2016): 79.57 | Impact Factor (2017): 7.296
Volume 7 Issue 11, November 2018
www.ijsr.net
Licensed Under Creative Commons Attribution CC BY
Phytoremediating Potentials of Sida acuta and
Duranta erecta for Lead, Cadmium, Cobalt and
Zinc
Anarado, C.E.1, Anarado, C.J.O.2, Agwuna, C.3, Okeke, M.O.4, Okafor, P.C.5
Department of Pure and Industrial Chemistry, Nnamdi Azikiwe University. P.M.B. 5025, Awka, Anambra State, Nigeria
Abstract: Recently pollution of the environment has gathered an increased global interest. In this respect, contamination of soils with
heavy metals has always been considered a critical challenge in the scientific community . Remediation of soil contaminated by heavy
metals is necessary in order to reduce the associated risks, make the land resource available for agricultural production, enhance food
security, and scale down land tenure problems. Immobilization, soil washing, and phytoremediation are frequently listed among the best
available technologies for cleaning up heavy metal contaminated soils but have been mostly demonstrated in developed countries. Non-
edible African plants Sida acuta and Duranta erecta were used to study the absorption of Cadmium, Lead Zinc and Cobalt from soils
inoculated with the metal ions. 0.1M, 0.5M and 1M solutions of the metal ions were used in the inoculation. The Leaves, stems and roots
of Sida acuta and the stems and roots of Duranta erecta were collected in the first instance at six weeks, and then, at ten weeks of
planting. Atomic Absorption Spectrophotometer was used to determine the metal ion concentration in the plants’ parts. Lead was more
absorbed by Sida acuta than did Duranta erecta, with the highest absorption of 1.223mg/kg in the former occurring in the roots.
Absorption increased as the concentration of the inoculant solution increased, and also on moving from 6 weeks’ to 10 weeks’ samples
for concentrations less than 0.1M. Cadmium was the only absorbed by Sida acuta, with a highest value of 6.495mg/kg in the roots,.
Duranta erecta was poisoned by Cd2+ in all concentrations. Zinc was more absorbed by Duranta erecta than did Sida acuta, with the
highest absorption of 7.898mg/kg in the former occurring in stems. Absorption increased as the concentration of the inoculants solution
increased. Cobalt was most absorbed by Sida acuta with the highest value of 9.354mg/kg found in the stem. Generally, Phytotoxicity was
shown in the plants at inoculants concentration above 0.5M, after 6 weeks except for Duranta erecta inoculated with Zn2+. The tolerance
for Lead, Cadmium, and Cobalt by Sida acuta show a good promise for its phytoremediation and recovery.
Keywords: Phytoremediation ;Sida acuta; Duranta erecta; Phytotoxicity; Lead; Cadmium; Cobalt, Zinc
On behalf of all authors, the corresponding author states that there if no conflict of interest
1. Introduction
One of the greatest problems that the world is facing today is
that of environmental pollution, increasing with every
passing year and causing grave and irreparable damage to
the earth(Meagher, 2000).
Industrialization is considered vital to the nation’s socio-
economic development as well as its standing in the
international community. Ideally, the siting of industries
should achieve a balance between socio- economic and
environment considerations(Mohammedand Folorunsho
2015).
In recent years, heavy metal contamination has become a
serious problem all over the world as these metals persist in
the soil for longer period due to their non
biodegradability(Kavitha et al, 2013). Since the beginning of
the industrial revolution, soil pollution by these toxic metals
has accelerated dramatically and has contributed to a variety
of toxic effects on living organisms. Soils as the major sink
have been contaminated by heavy metals and metalloids
through emissions from the rapidly expanding industrial
areas, sewage sludge, pesticides, wastewater irrigation, coal
combustion residues, spillage of petrochemicals, and
atmospheric deposition (Raymond et al, 2011, Aremu et al,
2010). Heavy metal pollution of the soil is caused by
various metals, especially Cu, Ni, Cd, Zn Cr and
Pb(Singh and Kalamdhad, 2011).
Heavy metal contamination of soil may pose risks and
hazards to humans and the ecosystem through: direct
ingestion or contact with contaminated soil, the food chain
(soil-plant-human or soil-plant-animal-human)( McLaughlin
et al, 2000). Lead is a highly toxic metal whose widespread
use has caused extensive environmental contamination and
health problems in many parts of the world(Monisha et al,
2014). The decontamination of soil and wastes polluted with
anthropogenic chemical is a global problem that has
consumed considerable economic resources(Chambers et al,
1991, Watts, 1997, Baker et al, 1994).
Presently, phytoremediation has become an effective and
affordable technological solution used to extract and remove
heavy metal pollutants from polluted soil. Many species of
plants have been successful in absorbing heavy metal
pollutants such as lead, cadmium and others from the soil
and water(Tangahu at al, 2011, Foluso et al, 2009, Amin et
al, 2013, Otaru et al, 2013, Kavitha and Jegadeesan, 2014).
The health risks posed by these metals have continued to be
of global concern, and have made the European Union to
place thirteen metals on the High-Risk-Monitor level. These
include Arsenic, Cadmium, Cobalt, Chromium, Copper,
Mercury, Manganese, Nickel, Lead, Tin, and Thallium.
Lead, Cadmium, Zinc and Cobalt have been used in this
work to study the ability of two nonedible African plants
Sida acuta and Duranta erecta to phytoremediate soils
polluted with the metal ions in their +2 oxidation states.
Paper ID: ART20192715
DOI: 10.21275/ART20192715
969
International Journal of Science and Research (IJSR)
ISSN: 2319-7064
Index Copernicus Value (2016): 79.57 | Impact Factor (2017): 7.296
Volume 7 Issue 11, November 2018
www.ijsr.net
Licensed Under Creative Commons Attribution CC BY
2. Methods
Twenty five seedlings, each, of the two plants were grown
on soils isolated in polyethylene pots. Forty eight pots were
inoculated with 0.1M, 0.5M and 1.0M solutions of Pb2+,
Zn2+, Co2+ and Cd2+, while controls were left. The plants’
parts were harvested after the sixth and eighth week of
inoculation. The harvested plants were washed, dried, and
ashed at 450oC. After digesting with concentrated HNO3,
Varian AA240 spectrophotometer was used to determine the
metal ions concentrations absorbed in the plants’ parts.
3. Results
Table 1: Concentration of Pb2+ absorbed by Sida acuta in
mg/kg
Stem (Ss) 1st Harvest 2nd Harvest
Ss1 0.397 0.496
Ss2 0.489 0.634
Ss3 1.108 Died
Root(SR) 1st Harvest 2nd Harvest
SR1 0.417 0.523
SR2 0.563 0.985
SR3 1.223 Died
Leaf(SL) 1st Harvest 2nd Harvest
SL1 0.358 0.405
SL2 0.425 0.597
SL3 0.713 Died
Table 2: Concentration of Pb2+ absorbed by Duranta erecta
in mg/kg
STEM(Ds) 1st Harvest 2nd Harvest
Ds1 0.251 Died
Ds2 2.400 Died
Ds3 Died Died
Root(ER) 1st Harvest 2nd Harvest
DR1 0.197 Died
DR2 1.658 Died
DR3 Died Died
Table 3: Concentration of Cd2+ absorbed by Sida acuta in
mg/kg
Stem (DS) 1st Harvest 2nd Harvest
Ss4 1.423 2.004
Ss5 4.001 Died
Ss6 5.241 Died
Root(DR) 1st Harvest 2nd Harvest
SR4 1.859 2.326
SR5 4.510 Died
SR6 6.495 Died
Leaf(DL) 1st Harvest 2nd Harvest
SL4 0.921 1.675
SL5 3.577 Died
SL6 4.932 Died
Table 4: Concentration of Cd2+ absorbed by Duranta erecta
in mg/kg
STEM(Ds) 1st Harvest 2nd Harvest
Ds4 Died Died
Ds5 Died Died
Ds6 Died Died
Root(DR) 1st Harvest 2nd Harvest
DR4 Died Died
DR5 Died Died
DR6 Died Died
Table 5: Concentration of Co2+ absorbed by Sida acuta in
mg/kg
Stem (DS) 1st Harvest 2nd Harvest
Ss7 7.421 Died
Ss8 8.252 Died
Ss9 9.354 Died
Root(DR) 1st Harvest 2nd Harvest
SR7 6.089 Died
SR8 6.595 Died
SR9 8.074 Died
Leaf(DL) 1st Harvest 2nd Harvest
SL7 6.853 Died
SL8 7.532 Died
SL9 8.901 Died
Table 6: Concentration of Co2+ absorbed by Duranta erecta
in mg/kg
STEM(Ds) 1st Harvest 2nd Harvest
Ds7 3.689 Died
Ds8 4.725 Died
Ds9 Died Died
Root(DR) 1st Harvest 2nd Harvest
DR7 2.142 Died
DR8 3.986 Died
DR9 Died Died
Table 7: Concentration of Zn2+ absorbed by Sida acuta in
mg/kg
Stem (Ss) 1st Harvest 2nd Harvest
Ss10 2.347 2.418
Ss11 2.515 2.663
Ss12 4.441 Died
Root(SR) 1st Harvest 2nd Harvest
SR10 2.409 2.434
SR11 2.557 2.731
SR12 4.520 Died
Leaf(DL) 1st Harvest 2nd Harvest
SL10 1.857 2.001
SL11 2.409 2.605
SL12 3.713 Died
Table 8: Concentration of Zn2+ absorbed by Duranta erecta
in mg/kg
STEM(Ds) 1st Harvest 2nd Harvest
Ds0 3.252 3.970
Ds11 3.754 5.078
Ds12 7.571 7.898
Paper ID: ART20192715
DOI: 10.21275/ART20192715
970
International Journal of Science and Research (IJSR)
ISSN: 2319-7064
Index Copernicus Value (2016): 79.57 | Impact Factor (2017): 7.296
Volume 7 Issue 11, November 2018
www.ijsr.net
Licensed Under Creative Commons Attribution CC BY
Root(DR) 1st Harvest 2nd Harvest
DR10 2.573 2.834
DR11 2.975 3.422
DR12 3.721 3.115
CODES: S- Sida acuta, D-Duranta erecta, s- stem, R- root,
L- leaf, 1,4,7,10= 0.1M, 2,5,8,11= 0.5M, 3,6,9,12= 1.0M
4. Discussions
The result of the analysis generally showed that some
African plants could be used to phytoremediate soil polluted
with Pb2+, Cd2+, Co2+ and Zn2+. Zinc was most absorbed by
both plants. Lead was more absorbed by Sida acuta than did
Duranta erecta, with the highest absorption of 1.223mg/kg
in the former occurring in the roots. Absorption increased as
the concentration of the inoculant solution increased, and
also on moving from 6 weeks’ to 10 weeks’ samples for
concentrations less than 0.1M. Phytotoxicity was shown in
the plants at inoculants concentration above 0.5M, after 6
weeks for Sida acuta, and from time of planting to 10 weeks
for Duranta erecta. Cadmium was the only absorbed by
Sida acuta, with a highest value of 6.495mg/kg in the roots,
Sida acuta could not tolerate Cd2+ as concentration of the
inoculant solution increased, and also on moving from 6
weeks’ to 10 weeks’. Duranta erecta was poisoned by Cd2+
in all concentrations. Zinc was more absorbed by Duranta
erecta than did Sida acuta, with the highest absorption of
7.898mg/kg in the former occurring in stems. Absorption
increased as the concentration of the inoculants solution
increased. Cobalt was most absorbed by Sida acuta with the
highest value of 9.354mg/kg found in the stem. Generally,
Phytotoxicity was shown in both plants at inoculants
concentration above 0.5M, after 6 weeks except for Duranta
erecta inoculated with Zn2+. The tolerance for Lead,
Cadmium, and Cobalt by Sida acuta shows a good promise
for its phytoremediation and recovery.
5. Conclusion
Soil is the fundamental foundation of our agricultural
resources, food security, global economy and environmental
Quality. The need to decontaminate the soils of heavy metals
cannot be overemphasized. Sida acuta and Duranta erecta
were used. It can be safely concluded that sida acuta has
better phytoremediating potential for Pb2+, Cd2+ and Co2+
than did Duranta erecta. Duranta erecta which cannot be
used to phytoremediate Cd2+ had better phytoremediating
potential for Zn2+than did Sida acuta.
References
[1] Amin M., Hamidi A. A., Mohammad A. Z., Shuokr Q.
A., M. Razip B. S.(2013),
[2] Phytoremediation of Heavy Metals from Urban Waste
Leachate by Southern Cattail (Typha domingensis).
International Journal of Scientific Research in
Environmental Sciences (IJSRES), 1(4):63-70,
[3] Aremu, M.O., Atolaiye B.O. and Labaran, L.(2010),
Environmental Implication of metal concentrations in
soil, plant foods and pond in area around the Derelict
Udege Mines of Nasarawa State, Nigeria. Bull. Chem.
Soc. Ethiop. 24(3): 351-360
[4] Baker, A.J.M. McGrath, S.P. Sidoli, C.M.D. Reeves,
R.D.(1994), The possibility of in situ heavy metal
decontamination of polluted soils using crops of metal-
accumulating plants. Elsevier, 11(1-4):41-49.
[5] Chambers, C.D., Willis, J., Giti-Pour, S., Zieleniewski,
J.L., Rickabough, J.F., Mecca, M.I., Pasin, B., Sims,
R.C., Sorensen, D.L., Sims, J.L., McLeam, J.E.,
Mahmood, R.R., Wagner, K.,(1991), In situ treatment of
Hazardous Waste- contaminated Soils, 2nd edn, Noyes
Data Corporation, Park Ridge, New York.
[6] Foluso O.A., Bamidele I.O., Kayode O.A.,(2009),
Phytoremediation potential of Eichornia crassipes in
metal-contaminated coastal water.Elsevier bioresource
technology, 100(19):4521-4526
[7] Kavitha, B., Jothimani, P., Ponmani, S., Sangeetha, R.,
(2013). Phytoremediation of Heavy metals- A review,
International Journal of Research studies in Bioscience,
Coimbatore, 1:17-23
[8] Kavitha, K. K. and Jegadeesan, M.(2014), Mercury and
cadmium accumulation in selected weed plants:
Implications for phytoremediation. Asian Journal of
Plant Science and Research, 4(5):1-4
[9] Meagher, R.B.,(2000), Phytoremediation of toxic
elemental and organic pollutants, current opinion in
plan Biology, 3(2): 153-162
[10] McLaughlin,M. J. Zarcinas,B. A. Stevens, D. P. and
Cook, N.(2000) “Soil testing for heavy
metals,” Communications in Soil Science and Plant
Analysis, 31(11): 16611700,
[11] Mohammed, S. A.1 and Folorunsho, J.O.(2015), Heavy
metals concentration in soil and Amaranthus retroflexus
grown on irrigated farmlands in the Makera Area,
Kaduna, Nigeria. Journal of Geography and Regional
Planning, 8(8): 210-217
[12] Monisha J., Tenzin T., Naresh A., Blessy B. M.,
and Krishnamurthy N. B.(2014), Toxicity, mechanism
and health effects of some heavy metals.
Interdisciplinary Toxicology. 7(2): 6072.
[13] Otaru, A.J., Ameh, C.U., Okafor, J.O., Odigure, J.O.,
Abdulkareem, A.S and Ibrahim, S.(2013), Study on the
Effectiveness of Phytoremediation in the Removal of
Heavy Metals from Soil Using Corn, International
Journal of Computational Engineering Research03(4):
87-93.
[14] Raymond A. Wuana and Felix E. Okieimen(2011),
“Heavy Metals in Contaminated Soils: A Review of
Sources, Chemistry, Risks and Best Available Strategies
for Remediation,” ISRN Ecology, Article ID 402647, p
20. https://doi.org/10.5402/2011/402647.
[15] Singh Jiwan and Kalamdhad Ajay S.(2011), Effects of
Heavy Metals on Soil, Plants, Human Health and
Aquatic Life. International Journal of Research in
Chemistry and Environment, 1(2): 15-21
[16] Tangahu, B.V., Abudulla, S.T.S., Basri, H., Anuar, N.,
and Mukhlisin, M.,(2011), A Review on heavy metal
(As, Pb and Hg) uptake by plants through
phytoremediation, International Journal of Chemical
Engineering, Malaysia, ID 939161: 1-31
[17] Watts R.J. (1997), Hazardous Wastes: Sources,
Pathways and Receptors. John Wiley, New York.
Paper ID: ART20192715
DOI: 10.21275/ART20192715
971
... f. 0.1M, 0.5M and 1M Highest Cd concentration of 6.495 mg kg -1 was absorbed and was unable to tolerate further cadmium stress. (Anarado et al., 2018) Al- Khayri et al. 10.3389/fpls.2022.1047410 Frontiers in Plant Science frontiersin.org ...
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