Original Research
POTENTIAL OF
WATER HYACINTH (EICHHORNIA CRASSIPES
L.) FOR PHYTOREMEDIATION OF HEAVY METALS FROM WASTE WATER
*NAZIR MI1,
*IDREES I2, DANISH P1, AHMAD S3, ALI Q1,
MALIK A1
1Institute of Molecular Biology and Biotechnology, The
University of Lahore, Lahore, Pakistan
2Department of Chemical Engineering, COMSATS University
of Information and Technology, Lahore, Pakistan
3Institute of
Agricultural Sciences, University of the Punjab, Lahore, Lahore, Pakistan
Corresponding
author: muhmmadirtaza@gmail.com,
ijlalidrees2@gmail.com
(Received, 9th February 2020, Accepted 24th April
2020)
Abstract: The present study was carried out to
determine the potential for phytoremediation of water hyacinth (Eichhornia
crassipes) plant for Cadmium (Cd), Arsenic (Ar), and Mercury (Hg) absorption.
The samples were collected from Dhamthal, Zafarwal and Narowal. The plant
samples were cut into their parts and dried at room temperature for 25-30 days
until they were fully dried. The change in fresh weight and dry weight was
examined. The data of collected samples was recorded and statistically
analyzed, which revealed the significance of results for different localities.
The lower coefficient of variation was recorded for all studied traits which
revealed that there was consistency among the results for different localities.
For our study the plant's percentage removal of metals was determined using
atomic absorption spectroscopy in plant sample as well as water sample. Metal
uptake happened at variable degrees. The water hyacinth uptake the largest
metal uptake per dry weight of water hyacinth was 166.25ppm for cadmium and the
smallest 0.032ppm was for mercury. In water sample highest amount of metal was
177.25ppm for cadmium and lowest 0.012ppm was for arsenic. It was found from
our study that the water hyacinth (Eichhornia crasssipes) uptake cadmium (cd)
metal from sewage water in highest amount as compare to arsenic and mercury. It
was suggested that the use of water hyacinth plant may be helpful to remove
heavy metals from waste water to minimize the heavy metal pollution of water.
Keywords: Water hyacinths, phytoremediation,
cadmium, arsenic, mercury
Introduction
Our earth contains over 70% of water. The
human-accessible freshwater measure is only 0.01% and the rest being bound in
ice (Ahmed et al.,
2015). This little extent of the earth's absolute water is ending up
progressively contaminated because of different anthropogenic exercises like
unpredictable transfer of civil and mechanical waste and enormous scale
utilizations of synthetics in agriculture (Soomro et al.,
2011; Zubair et al.,
2016). Many substances have been registered as poisons in freshwater and
incorporating acids such as alkali, anions (e.g. sulfide, cyanide) household
wastewater and homestead compost, chlorine gases, heavy metals (cadmium,
arsenic, mercury) supplements (phosphates, nitrates) oil and oil fumes etc.
Heavy metals are hard to expel from amphibian environment since they are
non-degrade able. There are numerous procedures present that evacuate heavy
metals but they all are costly. Therefore, it is necessary to develop such
systems which are eco-accommodating and financially savvy for getting the waste
metals expel from the environment (Erakhrumen and Agbontalor, 2007; Idrees et al., 2017). Phytoremediation
is a technology in which eliminates dangerous substances from the environment
with the help of plants and micro organisms that present soil. Heavy metals
take up by the plant through phytoremediation innovations is utilizing these
instruments of phytoextraction, phytostabilisation, rhizofiltration, and
phytovolatilization (Dushenkov, 2003). Phytoextraction is the
take-up / ingestion and translocation of contaminants by plant roots into the
plant shoots over the ground (Rulkens et al.,
1998). Phytostabilization is the use of certain plant species to immobilize
contaminants from soil and groundwater through ingestion and root adsorption
process (Ghosh and Singh, 2005). Rhizofiltration
is the adsorption or precipitation on plant roots or ingestion in the
fundamental foundations of contaminants that are arranged to clean up
simultaneous wastewater that covers the root zone (Salt et al.,
1995). Phytovolatilization is the uptake contaminants and convert into
volatile compounds and ispersed in the air with the help of stomata (Ghosh and Singh, 2005).
Phytodegradation includes the breakdown of complex natural mixes into more
straight forward structure and these substances present into plant tissues (Chaudhry et al.,
1998). There are 400 types of
hyperaccumulators use for the phytoremediation procedure e.g A. racemouses,
Zea mays, Eichhornia crassipes etc. The Eichhornia crassipes is the
most idealistic oceanic plant. The water hyacinth (Eichhornia crassipes)
assume a significant job in the phytoremediation of poisons like cadmium,
arsenic, cobalt, nickel, mercury and lead from antiquated time to present day
era (Idrees et al., 2017). It becomes quick with no exceptional requirements.
The different sorts of sea-going plants are helpful but the water hyacinth has
capacity to remediate numerous kinds of substantial metals. Therefore, in this
investigation utilize this plant (Téllez et al., 2008). In this paper
the principle spotlight was on examining the phytoremediation productivity of
water hyacinth in expelling heavy metals like mercury, cadmium and arsenic from
the waste water.
Material and
methods
This
study was conducted to investigate the metal uptake capacity of water hyacinth
on heavy metals like Lead, Arsenic, Cadmium, Mercury etc. The water hyacinth (Eichhornia crassipes) plants used in the
study were obtained from the different local areas of Narowal, Punjab Pakistan.
Narowal is situated at northeast side of Punjab. The sample of water hyacinth collects
from 3 different local areas of Narowal. From one area take 3 healthy plants
with roots and water in the plastic bottle as a sample to check the water
quality, water contaminants and presence of heavy metals before and after the
experiment. According to this procedure, obtained 9 plants sample and 3 water
sample and numbering the sample according to the area. Unwanted debris like
insects larvae, dust particles and other epiphytes were removed from the plants
before being washed by the water. Than weight the water hyacinth on weight
balance and measuring the length of plant by measuring scale. After this procedure, separate the
plant leaves, stem and root with surgical blade and then weight all the parts
of the plant separately. After this, plants allow to dry under the room
temperature until all the separates parts were fully dried. The data was
collected for various seedling morphological traits; plant height (PH),
stem/root fresh weight ratio (SRFWR), stem/root dry weight ratio (SRDWR), root
moisture percentage (RM%) and stem moisture percentage (SM%). The data was statistically
analyzed through analysis of variance techniques by using Statistix8.1
software. After this procedure, one dry plants sample and water sample from
each location selected and evaluate the metal concentration through atomic
absorption spectroscopy. The results was shown in the graph for compare the
metals concentrations among different localities.
Results and discussions
Plant Height
The average plant height under all studied treatments was recorded as 35.244±0.2388cm.The lower value of
coefficient of variation was 1.17% (Table 1). The
results indicated that the higher plant (37.033cm) under locality Narowal and,
locality Dhamthal (36.100cm) and was found while lowest plant was for control
(32.600cm) under locality Zafarwal (Figure 1). Plant heights vary according to
different localities. The higher plant height indicated that the growth of hyacinths was higher which leads towards the
increase in plant height because of higher photosynthetic rate under available
nutrient resources in water. The accumulation of organic and inorganic compound
was higher which indicated that the accumulation of heavy metals may also be
higher in stem of hyacinths plants (Ingole and Bhole, 2003; Mahmood et al.,
2005).
Figure
1. Plant height of water hyacinth under different localities
Stem/root
fresh weight ratio
It
was found from results that the average stem/root fresh weight ratio under all studied treatments
was recorded as 0.3478±0.001925. The lower value of coefficient of variation
(0.96%) for stem/root fresh weight ratio indicated that there was consistency
among the results which also cleared that the results were reliable for plant
of water hyacinth under different localities (Table 1). In Dhamthal
fresh weight ratio was (0.29) in Zafarwal fresh weight ratio was (0.53) and in
Narowal weight ratio is (0.22) (Figure 2). The higher
stem/root fresh weight ratio indicated that the amount of absorbed moisture
contents was higher in stem and roots. The higher ratio revealed that the hyacinths plants may survive under harsh
conditions because of higher storage ability of stems and roots (Dushenkov, 2003; Idrees et al., 2017; Rulkens et al., 1998).
Figure 2. Stem/root fresh weight ratio of water hyacinth under different
Stem/root dry weight ratio
It
was found from results that the average stem/root dry weight ratio under all studied
treatments was recorded as 0.3769±0.00419. The lower value of coefficient of
variation (1.93%) for stem/root dry weight ratio indicated that there was
consistency among the results which also cleared that the results were reliable
for plant of water hyacinth under different localities (Table 1).
In Dhamthal dry weight ratio is (0.31) in Zafarwal dry weight ratio is (0.4)
and in Narowal dry weight ratio is (0.39) (Figure 3). The higher
ratio revealed that the hyacinths plants may survive
under harsh conditions because of higher storage ability of stems and roots (Carbonell et al., 1998; Idrees et al., 2017; Soomro et al.,
2011).
Figure 3. Stem/root dry weight ratio of water hyacinth under different
localities
Root moisture percentage
It
was found from results that the average root moisture percentage under all studied
treatments was recorded as 91.650±0.0809%. The lower value of coefficient of
variation (0.15%) for root moisture percentage indicated that there was
consistency among the results which also cleared that the results were reliable
for plant of water hyacinth under different localities (Table 1).
In Dhamthal moisture percentage was (90.064%). In Zafarwal moisture percentage
was (93.75%) and in Narowal moisture percentage was (91.5%) (Figure 4).
The higher root moisture percentage revealed that the hyacinths plants may survive under harsh
conditions because of higher storage ability of roots (Idrees et al., 2017; Marin et al., 1993).
Stem moisture percentage
It
was found from results that the average stem moisture percentage under all studied
treatments was recorded as 92.097±0.0437%. The lower value of coefficient of
variation (0.08%) for stem moisture percentage indicated that there was
consistency among the results which also cleared that the results were reliable
for plant of water hyacinth under different localities (Table 1).
In Dhamthal moisture percentage was (90.064%). In Zafarwal moisture percentage
was (93.75%) and in Narowal moisture percentage was (95.5%) (Figure 5).
The higher root moisture percentage revealed that the hyacinths plants may survive under harsh
conditions because of higher storage ability of stem (Mahmood et al., 2005; Tiwari et al., 2007).
Figure 4. Root moisture percentage of water hyacinth under different
localities
Figure 5. Stem moisture percentage of water hyacinth under different
localities
Table 1. Analysis of variance for various
morphological traits of water hyacinths
Source |
Stem moisture % |
Root moisture % |
Stem/root dry weight ratio |
Stem/root fresh weight ratio |
Plant Height cm |
Replication |
0.0043 |
0.03687 |
0.00004 |
0.00001 |
0.0221 |
Locality |
60.5133* |
6.3135* |
0.00680* |
0.07874* |
16.3878* |
Error |
0.0057 |
0.01961 |
0.00005 |
0.00001 |
0.1711 |
Grand Mean |
92.097 |
91.60 |
0.3769 |
0.3478 |
35.244 |
CV % |
0.08 |
0.15 |
1.93 |
0.96 |
1.17 |
Standard error |
0.0437 |
0.0809 |
0.00419 |
0.00192 |
0.2388 |
* =
Significant at 5% probability level
Heavy metals concentration in plant and water
samples
Cadmium
The various
metals assayed in the experiment were found present in test plants and water
samples. However, the concentration of the metals e.g. Cadmium, Arsenic and Mercury in the test plants differed
significantly when compared to the different localities as well as the
concentration of the metals Cadmium, Arsenic and Mercury in the test water
samples differed significantly when compared to different localities. In figure
6 indicate that Cadmium found in plant and water sample according to different
localities (Dhamthal, Zafarwal, Narowal). In Dhamthal cadmium in water sample
was (0.00ppm) and in plant sample was (0.002ppm). In Zafarwal cadmium in water
sample is (30.25ppm) and (29.25ppm) in plant sample. In Narowal cadmium metal
in water sample is (177.25ppm) and in plant sample was (166.25ppm).
Arsenic
In figure 7
indicate that in Dhamthal arsenic in water sample was (0.04ppm) and in plant
sample was (0.09ppm). In Zafarwal arsenic in water sample was (0.03ppm) and
(0.02ppm) in plant sample. In Narowal arsenic metal in water sample is
(0.012ppm) and in plant sample was (0.025ppm).
Mercury
In figure 8
indicate that in Dhamthal mercury from water sample was (0.00ppm) and in plant
sample was (0.05ppm). In Zafarwal mercury in water sample was (28.23ppm) and
(0.04ppm) in plant sample. In Narowal mercury metal in water sample was (145.25ppm)
and in plant sample was (0.032ppm). The findings of the current research (Figures 6, 7 and 8) showed that the
water hyacinth can bioaccumulate some of these metals under separate localities
(Dhamthal, Zafarwal, Narowal), such as cadmium, arsenic and mercury (Carbonell et al., 1998; El‐Gendy et al.,
2006; Ingole and Bhole, 2003; Mahmood et al.,
2005; Upadhyay and Tripathi, 2007; Zhu et al.,
1999). In figure 6 indicate that cadmium concentration in Dhamthal was
very low in plant sample is (0.002ppm) as well as cadmium metal not found in
water sample this means that the water of Dhamthal contain very lower
concentration of cadmium. The amount of cadmium were lower than those reported
in literature (El‐Gendy et al., 2006; Téllez et al.,
2008). The amount of cadmium were higher than those reported in (Marin et al., 1993; Upadhyay and Tripathi, 2007). In figure 7 indicate that arsenic concentration in Dhamthal is
very high in plant sample was (0.09ppm) as well as arsenic metal found in water sample is (0.04ppm) this means
that the water of Dhamthal very polluted which contain very higher
concentration of arsenic. The amount of arsenic were lower than those reported
in literature (Mahmood et al., 2005). The amount of arsenic were higher than those reported in (Marin et al., 1993). In figure 8 indicate that mercury concentration in Dhamthal is very low
in plant (0.05ppm) and in water mercury not found means that water of Dhamthal
contains very low amount of mercury. The amount of mercury were lower than
those reported in literature (Abedin et al., 2002).
Figure 6. Cadmium concentration in water and plants
sample under different localities
Figure 7. Arsenic concentration in water and plants
sample under different localities
Figure 8. Mercury concentration in water and plants
sample under different localities
Conclusion
Phytoremediation is a
remediation technology that uses green plants to clean up contaminants from the
atmosphere. Phytoremediation can be an option to treat heavy metal contaminated
regions as a green technology. According to our research, water hyacinth plant
has a strong potential as a bioaccumulator of heavy metals and can be used for
heavy metal phytoremediation. Our findings have shown the various options of
using water hyacinth to remove pollutants in waste water. It has been found
that water hyacinth is appropriate for managing urban waste water. It has also been
shown that water hyacinth among aquatic plants is a reasonable and feasible way
to absorb toxic nutrients and improve the quality of the water. The research
showed that water hyacinth (Eichhornia
crassipes) could efficiently
phytoremediate contaminated water containing metals such as cadmium (Cd),
arsenic (Ar) and mercury (Hg), thereby decreasing the potential environmental
danger from untreated waste water to the environment. According to our study
the water hyacinth uptake highest amount of metal per dry weight of water
hyacinth was 166.25ppm for cadmium while lowest, 0.032ppm for mercury. It was
suggested from our study that the water hyacinth (Eichhornia crasssipes) uptake cadmium (Cd) metal from sewage water
in highest amount as compare to arsenic and mercury. Future research will
explore the potential of water hyacinth as a bio-agent for phytoremediate
polycyclic aromatic hydrocarbon, a significant toxicant from petroleum spills
in Nigeria's oil-producing countries.
Conflict
of interest
The authors declared the absence of any
conflict of interest.
References
Dushenkov, S. (2003).
Trends in phytoremediation of radionuclides. Plant and soil 249, 167-175.
El‐Gendy, A., Biswas, N., and Bewtra, J. (2006). Municipal landfill leachate
treatment for metal removal using water hyacinth in a floating aquatic system. Water environment research 78, 951-964.
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