ArticlePDF Available

Removal of heavy metals from waste water using water hyacinth


Abstract and Figures

Water pollution has become one of the most serious problems of today’s civilization. In the last few years considerable amount of research has been done on the potential of aquatic macrophytes for pollutant removal or even as bio-indicators for heavy metals in aquatic ecosystems. Water hyacinth is one of the aquatic plant species successfully used for wastewater treatment. It is very efficient in removing pollutants like suspended solids, BOD, organic matter, heavy metals and pathogens. This paper mainly focuses on the treatment of waste water using the plant ‘water hyacinth’ and has given emphasis to the removal of heavy metals by the plant. Water hyacinth’ could grow in sewage; they absorb and digest the pollutants in wastewater, thus converting sewage effluents to relatively clean water. Thus, the plants hold promise as a natural water purification system, which could be established at a fraction of the cost of a conventional sewage treatment facility. The study conducted in this regard revealed how efficiently wastewater could be treated using the plant ‘Water hyacinth’.
Content may be subject to copyright.
ACEEE Int. J. on Transportation and Urban Development, Vol. 01, No. 01, Apr 2011
© 2011 ACEEE
DOI: 01.IJTUD.01.01.39 48
Removal of Heavy Metals from Waste Water Using
Water Hyacinth
A. Mary Lissy P N¹, B. Dr. G. Madhu²
¹Lecturer, Department of Civil Engineering,
Toc H Institute of Science and Technology,Arakkunnam, Kochi, India.
² Professor and Head (Safety & Chemical Engg ) School of Engineering,
Cochin University of Science and Technology, Kochi, India.
Abstract— Water pollution has become one of the most serious
problems of today’s civilization. In the last few years
con siderable amount of research has been done on the
potential of aquatic macrophytes for pollutant removal or even
as bio-indicators for heavy metals in aquatic ecosystems. Water
hyacinth is one of the aquatic plant species successfully used
for wastewater treatment. It is very efficient in removing
pollutants like suspended solids, BOD, organic matter, heavy
metals and pathogens. This paper mainly focuses on the
treatment of waste water using the plant ‘water hyacinth’ and
has given emphasis to the removal of heavy metals by the
plant. Water hyacinth’ could grow in sewage; they absorb and
digest the pollutants in wastewater, thus converting sewage
effluents to relatively clean water. Thus, the plants hold
promise as a natural water purification system, which could
be established at a fraction of the cost of a conventional sewage
treatment facility. The study conducted in this regard revealed
how efficiently wastewater could be treated using the plant
‘Water hyacinth’.
Index Terms macrophytes, absorption , adsorption,
heliophytes, phytoextraction, bioaccumulators.
Water scarcity has been increasing all over the world
and in many countries may become absolute by the year
2025 “Ref. [17]”. This problem becomes more apprehensive
when recognizing that the severity of surface water pollution
is a worldwide problem “Ref. [18]”. To tackle the problem,
several measures for sustainable water resource utilization
have been developed, of which wastewater reclamation and
reuse is currently one of the top priorities “Ref. [14]”. It was
reported that domestic and Industrial discharges are
probably the two most important anthropogenic sources for
metals in the water environment “Ref. [4]”.
The presence of heavy metals in water are toxic even at
very low concentrations “Ref. [7]”. Pollution of the biosphere
with toxic metals has accelerated dramatically since the
beginning of the industrial revolution. Water hyacinth
(Eichhornia crassipes) an aquatic plant which could
successfully used for removing various pollutants from water
thus has great importance in wastewater treatment. It has a
huge potential for removal of the vast range of pollutants
from wastewater “Ref. [3]”.
In this paper the main focus was on studying the efficiency
of water hyacinth in removing dissolved solids, B.O.D, heavy
metals mainly chromium and copper from the waste water,
and the effect of the growth of water hyacinth on the pH of
the waste water. To achieve this objective, water hyacinth
was grown in synthetic wastewater prepared by adding
varying concentrate ions of Cr and Cu. The concentrations
of heavy metals, pH, B.O.D and total dissolved solids were
noted in the waste water before and after cultivating water
hyacinth and compared the results with the standard values.
Wastewater could be any water that has been adversely
affected in quality by anthropogenic influence. It comprises
liquid waste discharged by domestic residences, commercial
properties, industry, and agriculture and can encompass a
wide range of potential contaminants and concentrations
“Ref. [9]”. Treated wastewater can be reused as drinking water,
in industry and in the rehabilitation of natural ecosystems
“Ref. [15]”. Although the nature has a fantastic capacity to
deal with waste water and even pollution, with billions of
gallons of polluted and dirty water, it cannot do the work
alone. There are many technologies for wastewater treatment
that can help in re-establishing and preserving physical,
chemical and biological integrity of water. But the efficient
and ecofriendly methods lacked in this regard
A. Water Hyacinth
Water hyacinth (E.crassipes.) is a fast growing perennial
aquatic macrophyte and its name Eichhornia was derived
from well known 19th century Prussian politician J.A.F.
Eichhorn “Ref. [8]”. It is well known for its reproduction
potential and the plant can double its population in only
twelve days. Water hyacinth is also known for its ability to
grow in severe polluted waters. E.crassipes is well studied as
an aquatic plant that can improve the effluent quality from
oxidation ponds and as a main component of one integrated
advanced system for the treatment of municipal, agricultural
and industrial waste waters “Ref. [6]”.
ACEEE Int. J. on Transportation and Urban Development, Vol. 01, No. 01, Apr 2011
© 2011 ACEEE
DOI: 01.IJTUD.01.01.39
Division: Magnoliophyta
Class: Liliopsida
Subclass: Commeinidae
Super order: Commelinanae
Order: Pontederiales
Family: Pontederiaceae
Genus: Eichhornia
Water hyacinth is an aquatic vascular plant with rounded,
upright and shiny green leaves and lavender flowers similar
to orchids. Individual rosette is erect and free floating with
numerous stolons. Each one carries six to eight spirally
arranged succulent leaves that are produced sequentially on
a short vertical stem. Petioles are bulbous and spongy with
many air spaces which allow plants to float on a water surface
“Ref. [6]”.
Top petal has gold yellow spot bordered with blue line.
Root system of water hyacinth is dark blue in colour with
numerous stolons. New plants are formed at the end of these
stolons. Measured from flower top to root top E. crassipes
usually reach the height of 1.5m and more. When grown in
wastewaters water hyacinth is smaller and it often reaches
heights no more than 0.5 to 1.2m. Growth of water hyacinth is
primarily dependant on the ability of the plant to use solar
energy, nutrient composition of water, culture methods and
environmental factors. Plant growth is described in two ways,
firstly, by reporting the percentage of water surface covered
of a period of time and second and more useful method is by
reporting the plant density in units of wet plant mass per unit
of surface area.
This aquatic plant reproduced in both generative and
vegetative ways. That means new plants could be produced
from seeds or they represent clones derived from stolon
elongation due to division of auxiliary meristems of mother
Figure.1 Morphology of Water Hyacinth
At first these new rosettes are attached to mother plant but
stolons are very fragile so they could easily broken enabling
young individuals to float away and colonies new areas. Only
ten plants in just eight months could produce a population
of 655,330 individuals.
Water hyacinth is mainly reproduced by generative means
in its natural habitat and it produces large number of seeds.
The flowering period lasts for about fifteen days. When
flowering cycle ends flower stalk bends and the spike go
under the water surface and seeds are released directly into
the water. Each inflorescence contains normally 1 to 20 seed
capsules and capsule caries 3 to 250 seeds. In spite of the
production of this large number of seeds there are only 3 to
3.4 seeds per plant each year that could eventually able to
B. Ecological Factors
The environmentally-sound attribute of ecological
technology is its capability of resource recovery and reuse.
For instance, nutrients in nitrogenous and phosphorous
wastewater compounds are recycled into usable biomass by
means of the ecological food chains functioning in aquatic
ecosystems “Ref. [19]”.
Water hyacinth could grow best in warm waters rich in
macronutrients. Optimal water pH for the growth of this
aquatic plant is neutral but it could tolerate pH values from 4
to 10. This important characteristic enables E.crassipes to
treat different types of wastewater .Optimal water temperature
for growth is 28-30oC. Temperatures above 33oC inhibit further
growth. Optimal air temperature is 21-30oC. So if aquatic
systems with water hyacinth are constructed in colder
climates it would be necessary to build greenhouses for
maintaining optimal temperature for plant growth and
development. Low air humidity from 15% to 40% could also
be a limiting factor for undisturbed growth of water hyacinth.
E.crassipes tolerates drought well because it could survive
in moist sediments up to several months.
C. Effects Of Heavy Metals
Some heavy metals have bio-importance as trace elements
but, the biotoxic effects of many of them in human
biochemistry are of great concern . The term “heavy metals”
refers to any metallic element that has a relatively high density
and is toxic or poisonous even at low concentration. To a
small extent, they enter the body system through food, air,
and water and bio-accumulate over a period of time “Ref.
Heavy metals include lead (Pb), cadmium (Cd), zinc
(Zn),mercury (Hg), arsenic (As), silver (Ag) chromium
(Cr),copper (Cu) iron (Fe), and the platinum group elements
“Ref. [11]”. If the concentration of heavy metals exceeds their
limits in the drinking water, it can affect the human health.
Earlier experiments showed that at higher doses they can
cause anemia, liver and kidney damage and can even damage
circulatory and nervous systems “Ref. [7]”. The removal of
heavy metals from aqueous solutions has therefore received
considerable attention in recent years “Ref. [12]”.
D. Mechanisms of Waste Water Treatment Using Water
Aquatic macrophytes like water hyacinth uptake
contaminants and stores in its biomass. These plants are
called bioaccumulators as they accumulate the contaminants
in their tissues “Ref. [5]”. They have high tolerance against
contaminants like heavy metals and are able to absorb large
quantities. This method of extracting heavy metal from
ACEEE Int. J. on Transportation and Urban Development, Vol. 01, No. 01, Apr 2011
© 2011 ACEEE
DOI:1.IJTUD.01.01.39 50
polluted water bodies is called phytoextraction . The uptake
of contaminants is by three methods
 Root absorption- The roots absorb water together
with the contaminants in water. The presence of carboxyl ·
groups at the roots system induces a significant cation
exchange through cell membrane and this might be the
mechanism of moving heavy metal in the roots system where
active absorption takes place. In sewage systems, the root
structures of water hyacinth (and other aquatic plants) provide
a suitable environment for aerobic bacteria to function.
Aerobic bacteria feed on nutrients and produce inorganic
compounds which in turn provide food for the plants. The
plants grow quickly and can be harvested to provide rich and
valuable compost. Water hyacinth has also been used for the
removal or reduction of nutrients, heavy metals, organic
compounds and pathogens from water.
 Foliar absorption- In addition to root absorption,
plants could also derive low amounts of some contaminants
through foliar absorption. They are passively absorbed
through stoma cells and cracks in cuticle.
 Adsorption- The fibrous and feathery roots not only
trap suspended solids and bacteria, but provide attachment
sites for bacterial and fungal growth. The contaminants get
adsorbed to the root surface by the bacteria present there. It
is also due to ionic imbalance across the cell membrane.
Water hyacinth was collected from three different local
ponds. The experiments were conducted in tank as well as in
jars. This was done in order to find out the efficiency of the
plant in removing the pollutants when they were used as a
single plant in jars and also when they are used collectively
in tanks.
A. Water Hyacinth grown in Tank
A natural wetland was simulated in an RCC tank in
which the water hyacinth was grown. A tank of size 3m x 2.5m
x 1m having a capacity of 7.5m3 was constructed. The tank
was filled with 6000 litres of water. Then the water hyacinths
collected were grown in the tank.
B. Water Hyacinth grown in Jars
Eight quart size jars were filled with 1litre of water containing
chromium (1ppm) and copper (5ppm).The jars with chromium
and copper were then sorted separately into four treatments
with two jars in each treatment. The samples collected were
placed in three of the four treatments and two jars were
without plant as control as shown in “Fig. 3” & “Fig.4”.
The standard procedure was carried out with known
concentrations of chromium and copper. The change in pH,
TDS, B.O.D, Cr and Cu concentrations were found out at
regular intervals using APHA methods “Ref. [1]”.
The experimental results of various tests conducted
are shown below:
The results given in Table: 1 showed that the quality
of the water sample collected is within the W.H.O standards
“Ref. [2]”. So the study was carried out by adding known
concentrations of heavy metal ie; 1ppm of Cr and 5 ppm of
A. Results of the experiments carried out with Chromium
in the tank
Figure.5: Variation of chromium concentration in the tank
ACEEE Int. J. on Transportation and Urban Development, Vol. 01, No. 01, Apr 2011
© 2011 ACEEE
DOI:1.IJTUD.01.01.39 51
B. Results of Copper in tank
C .Results of experiments carried out in Jars with
Figure.11 Results of TDS
D. Results of experiments carried out in Jars with
Figure.12: Results of Copper in Jars
ACEEE Int. J. on Transportation and Urban Development, Vol. 01, No. 01, Apr 2011
© 2011 ACEEE
DOI:1.IJTUD.01.01.39 52
E .Discussions
The results of the experiments carried out in the tank
showed that the plant has the ability to absorb heavy metals
Chromium and copper from the waste water .The TDS values
increased on placing the plants in the tank .This increase
was due to the presence of clay or other fine particles present
in the plant roots. On subsequent days it showed that the
TDS value considerably decreased by the accumulation
process of water hyacinth. There was reduction in BOD also.
The jars with plant showed a considerable decrease in Cr
and Cu concentrations. For jars without plant, the decrease
of chromium and copper concentration was found to be very
less .Thus we could conclude that loss due to evaporation
and settlement were very less. There was no much change
for pH. The pH value was found to be between 6 and 8. The
value of TDS was found increasing. This might be attributed
to the decay of the single plant growing in the jar with high
Cr concentrations contributing to TDS content. The results
obtained indicated that water hyacinth could be used as an
effective means for the removal of heavy metals from waste
water if the same is used collectively as done in the RCC
The efficiency of waste water treatment was expressed
in terms of the variation in pH, biochemical Oxygen Demand
(BOD), total Dissolved Solids (TDS) and heavy metals before
and after treatment. When the plants were collectively grown,
the removal of pollutants from the water was very high. The
experimental results have shown that about 65% removal of
heavy metals could be achieved by water hyacinth. The plants
have also got the capacity to convert the accumulated
biomass into biogas. This system of treatment was cost
effective since cost of installation and maintenance was very
low. This system could be provided alone or together with
other systems used for treating waste water. In conclusion,
the present investigation demonstrated the feasibility of
adopting a “sustainable” and eco-friendly approach to sewage
waste water treatment using aquatic plant Eichhornia. Since
it was only a laboratory scale base - line study, further
investigations should be carried out in future on a large scale
particularly focusing on phytoremediation and resource
Authors are grateful to department of civil engineering,
TIST, Arakkunnam for the co-operation and support given
for the completion of this work. This work was supported by
Research centre of Toc H Institute of Science & Technology ,
[1] APHA (2002). Standard Methods for the Examination of Water
and Wastewater, American Public Health Association, AWWA,
and WPCF, Washington DC.
[2] G. S. Birdie (1992).Water supply and sanitary engineering,
Dhanpat Rai Publishing Company, New Delhi.
[3] Ayaz and Acka (2001). Treatment of wastewater by natural
systems, Environment International, 26,189-195.
[4] S. Muramoto and Y. Oki (1983),Removal of Some Heavy
Metals from Polluted Water by Water Hyacinth (Eichhornia
crassipes) ,Bulletin of Environmental Contaminants and
toxicology, 30, 170-177.
[5] Boyd, C. E. (1970). Vascular aquatic plants for mineral nutrient
removal from polluted waters. Economic Botany, 24, 95–103.
[6] Sangeeta Dhote & Savita Dixit(2009),Water quality improvement
through macrophytesa review, Environmental Monitoring
and Assessment,152:149–153
[7] Tiwari, S., Dixit, S., & Verma, N. (2007). An effective means of
bio-filtration of heavy metal contaminated water bodies using
aquatic weed Eichhornia crassipes, Environmental Monitoring
and Assessment, 129, 253–256.
[8] Shree N. Singh, Rudra D.Tripathi (2007), Environmental
bioremediation technologies, Springer.
[9] Goel, P.K. (1997). Water pollution, causes, effects and control.
New Age International (P) Ltd., publishers, New Delhi: 269.
[10] Athalye, R.P., Mishra, V., Goldin Quadros, Vidya Ullal and
Gokhale, K.S. (2001). Heavy metals in the abiotic and biotic
components of Thane Creek, India. Pollut. Res., 18(3): 329-
[11] Upadhyay, Alka R.; B. D. Tripathi (2007). “Principle and
Process of Biofiltration of Cd, Cr, Co, Ni & Pb from Tropical
Opencast Coalmine Effluent”. Water, Air, & Soil Pollution
(Springer) 180 (1 - 4):213–223..
[12] Abou-Shanab, R. A. I. et al.; Angle, JS; Van Berkum, P
(2007). “Chromate-Tolerant Bacteria for Enhanced Metal
Uptake by Eichhornia Crassipes (MART.)”. International
Journal of Phytoremediation 9 (2): 91–105.
[13] Sathyanarayanan, U. (2007): Textbook of Biotechnology Books
and Ailled (P) Ltd., Kolkata. pp. 667-707.
[14] Anderson, J., Adin, A., Crook, J., Davis, C., ultquist, R.,
Jimenez-Cisneros, B., Kenedy, W.,Sheik, N. , and Van der
Merwe, B., (2001).Climbing the ladder: a step by step
approach to international guidelines for waterrecycling. Water
Science Technology, 43, 1-8.
[15] Ch u, J., Chen, J., Wang, C., Fu, P. (2004). Wastewater reuse
potential analysis: implications for China’s water resource
management. Water Research, 38, 2746-2756.
[16] Nhapi I., Gijzen H.J. 2005. A 3-step strategic approach to
sustainable wastewater management. Water SA, Vol 31, No 1,
pp. 133-140
[17] Seckler, D., Barker R. and Amarasinghe U. (1999). Water
scarcity in the twenty-first century. International Journal of
Water Resources Development 15, 29-42.
[18] Yan, J., Wang, R., Wang, M. (1998). The fundamentalprinciples
and ecotechniques of wastewater aquaculture.Ecological
[19] Joel de la Noue, Niels de Pauw(1988). The potential of
micro algal technology Biotechnology Advances, Volume 6,
Issue 4, 1988, Pages725-770
... Besides, it has already been reported that industrial and domestic wastewaters are the predominant sources of heavy metals in the environment 46,47 . In 1986 the government of India launched the Ganga Action Plan intending to clean Ganga and its tributaries unfortunately, they have had little success in achieving their objectives and goals. ...
Full-text available
Water quality index (WQI) of Narora channel and health of endemic fish Bagarius bagarius and plant Eichhornia crassipes, district Bulandshahar, Uttar Pradesh, India were studied. Among the physicochemical properties of water, pH, D.O, Cr, Fe, Ni, and Cd were above the recommended standards. These factors lead to high WQI (4124.83), indicating poor quality and not suitable for drinking and domestic usage. In fish tissues, the highest metal load was reported in the liver (58.29) and the lowest in the kidney (33.73). Heavy metals also cause a lowering of condition indices. As expected, decreased serum protein (− 63.41%) and liver glycogen (− 79.10%) were recorded in the exposed fish. However, blood glucose (47.22%) and serum glycogen (74.69%) showed elevation. In the plant, roots (21.50) contained the highest, and leaves (16.87) had the lowest heavy metal load. Bioaccumulation factor (BAF) > 1, indicates hyperaccumulation of all metals. E. crassipes roots showed the highest translocation factor (TF)> 1 for Ni (1.57) and Zn (1.30). The high mobility factor (MF) refected the suitability of E. crassipes for phytoextraction of Mn, Cd, Zn, Fe, Ni, and Cu. Moreover, Bagarius sp. consumption could not pose any non-cancer risk. Although, lower cancer risk can be expected from Ni and Cr.
... As of 2020, more than 450 different plant species from at least 45 angiosperm families had been identified as heavy metal hyperaccumulators (Suman et al. 2018). The aquatic macrophyte species E. crassipes has been examined in more than ten such phytoremediation studies of heavy-metal polluted water systems, demonstrating strong capacity to extract Cr (i.e., 65% removal) and Cu (i.e., 61-97% removal, depending on initial concentrations) from synthetic wastewaters and simulated wetland environments (Lissy and Madhu 2011;Mokhtar et al. 2011). In one study, which focused on decontaminating heavy metals from agricultural activities, Zea mays plantings were shown to be useful in accumulating both Cr and Pb from soils (Braud et al. 2009). ...
Natural wetlands in Africa continue to decline in surface area and water quality. Still, there is scant information about the nature and causes of the decline, despite African countries’ increasing efforts to sustainably manage the wetlands. African countries have embarked on efforts to promote sustainable pathways to balance the development of wetlands for sustaining livelihoods with conservation and maintenance of ecosystem services, such as improvement of water quality and biodiversity. However, there is still inadequate information about the application of wetlands in remediation and the threats to wetlands under the pressures of changes in climate and population. This chapter reviews the status of Wetlands in Africa and their potential use in remediation to highlight emerging opportunities for sustainable management of ecosystems and uncovers the gaps and challenges that may deter proper implementation and application of wetlands for remediation of environmental problems in Africa. We recommend that constructed wetlands be integrated into management plans for conservation of both soil and water resources of watersheds and as parts of major restoration projects in Africa.
... As of 2020, more than 450 different plant species from at least 45 angiosperm families had been identified as heavy metal hyperaccumulators (Suman et al. 2018). The aquatic macrophyte species E. crassipes has been examined in more than ten such phytoremediation studies of heavy-metal polluted water systems, demonstrating strong capacity to extract Cr (i.e., 65% removal) and Cu (i.e., 61-97% removal, depending on initial concentrations) from synthetic wastewaters and simulated wetland environments (Lissy and Madhu 2011;Mokhtar et al. 2011). In one study, which focused on decontaminating heavy metals from agricultural activities, Zea mays plantings were shown to be useful in accumulating both Cr and Pb from soils (Braud et al. 2009). ...
Constructed wetlands and the associated flora and fauna have had important roles in human history, such as providing food, water purification, flood control, biological habitat, recreation, and education functions. As the human population increases and living space becomes limited, the integration of constructed wetlands into the urban landscape will become important. At the most basic ecological level, microalgae are important primary producers, providing an important source of energy for wetland organisms and their respective food webs that extend to terrestrial ecosystems. They are a potential renewable energy source, and as a nature-based solution, microalgae offer considerable environmental advantages over other types of renewable energy sources. Microalgae grow rapidly, sequester atmospheric carbon dioxide, nitrogen, and phosphorous and some species are rich in oils that can be used to produce different types of biofuel. We explored the bioremediation and renewable energy roles these simple, unicellular organisms could play in the future.KeywordsBiofuelBiogasBiomass energyBioremediationConstructed wetlandsMicroalgaeRenewable energyWise use
... Water hyacinth has potential economic, social and environmental values. Water hyacinth grows widely with a yield of 400 tons/ha, which will meet the requirements of 490 biogas production for cooking, silage for ruminant cattle, mushroom cultivation or fuel (coal briquettes) (Suthar,2022). in the alkaline soil, water hyacinth juice is put into the pond to raise the pH from 3.2 to 4.5, creating more nutrients in the water, especially creating a good environment for chlorella algae -which is the food of fry, especially flounder and marble goby (Jimenez, 2020). in its natural form, water hyacinth has the effect of absorbing heavy metals (such as lead, mercury, strontium) and thus, can be used to eliminate environmental pollution (Mary P.N, 2011). According to Dan viet newspaper, the current saltwater intrusion has caused death for water hyacinth, dozens of poor and disadvantaged households in Hoa Tien commune (vi Thanh city, Hau Giang province) who live on this plant have lost their jobs. ...
Water hyacinth is an aquatic plant, of which proliferation rate is extremely rapid as a weed, causing great economic, social and environmental damage. On the other hand, the water hyacinth also has potential economic value, because it is used as food for livestock, gas, fertilizer, environmental treatment, art crafts, decoration items, as well as herbal medicine. This research investigated the effects of concentrations of BA (Benzyl adenine) and NAA (Naphthylacetic acid) on in-vitro bud and root formation of Eichhornia crassipes [Mart.] Solms to create in-vitro sample source which is initially used in subsequent researches of water hyacinth. After 4 weeks of in-vitro culture, the results showed that the two-layer MS (Murashige Skoog) medium – the lower solid agar medium and the upper liquid medium – accompanied by aerobic culture conditions supplemented with 0.5 mg/L BA were suitable for bud proliferation. Next, these explants after destroying shoot apical meristem were transferred to MS medium supplemented with 0.75 mg/L BA suitable for bud development. The mature buds were transferred to MS medium supplemented with 0.25 mg/L NAA, suitable for rooting of water hyacinth and gave high survival rate (83.00%) when planted in the garden on hydroponic nutrient medium Howard of 600ppm.
... Date of publication 28 November 2022; date of current version 7 December 2022. This work was supported in part by European Social Fund (Resolución de 10 de mayo de 2017, de la Secretaría General de Ciencia, Tecnología e Innovación, por la que se resuelve la convocatoria de ayudas para la financiación de contratos predoctorales para formación de Doctores en los centros públicos de I+D pertenecientes al Sistema Extremeño de Ciencia, Tecnología e Innovación en el ejercicio 2017, expediente PD16001), in part by Consejería de Economía, Ciencia y Agenda Digital of the Junta de Extremadura, in part by European Regional Development It absorbs heavy metals and organic contaminants, allowing its utilization in wastewater treatments [5], [6], [7] and for heavy metal removal [8], [9]. It also has potential use as water hyacinth biomass in biochar [10], bio-oil, and syngas [11]. ...
Full-text available
Monitoring the spatio-temporal distribution of invasive aquatic plants is a challenge in many regions worldwide. One of the most invasive species on earth is the water hyacinth. These plants are harmful to biodiversity and create negative impacts on society and economy. The Guadiana river (one of the most important ones in Spain) has suffered from this problem since the early 2000 s. Several efforts have been made to mitigate it. However, invasive plants such as the water hyacinth are still present in seed banks at the bottom of the river and can germinate even more than a decade after. In this paper, we propose an automatic, based on remote sensing and deep learning techniques, to monitor the water hyacinth in the Guadiana river. Specifically, a multitemporal analysis was carried out during two years using images collected by ESA's Sentinel-2 satellite, analyzed with a convolutional neural network (CNN). We demonstrate that, with our strategy, the river can be monitored every few days and we are able to automatically detect the water hyacinth. Three experiments have been carried out to predict the presence of water hyacinth from a few scattered training samples, which represent invasive plants in different phenological stages and with different spectral responses.
Water hyacinth is a well-known aquatic plant worldwide because of its incredible properties like rapid growth in a tolerated environmental condition in more than 50 countries. This has been an issue of discussion among researchers and scientists over the past few decades due to severe difficulties in irrigation, navigation, and power generation. Researchers and scientists are trying to change the perception angle regarding control of it and also show a new phase of it as a resource because of its several valuable unique qualities, which can solve many problems. As a result, lots of research work has been undertaken on its control (especially biological control) and appropriate utilization in energy production (especially biogas), water and wastewater treatment. The main objective of this review paper is to show comprehensive information about the conducted research activities and their properties, control and utilization.
Full-text available
Water hyacinth (Eichhornia crassipes) is considered a prospective free-floating aquatic plant potentially used to address current issues on food, energy, and the environment. It can grow quickly and easily in various tropical and subtropical environments as long as it has access to adequate light and water to support photosynthetic growth. Ecosystems are threatened by their invasive growth and remarkable capacity for adaptation. However, managing this plant can result in valuable products. This paper demonstrates particle technologies that might be used to utilize water hyacinths, including brake pads, fertilizer, bioenergy, animal feed, phytoremediation agents, bioplastics, and adsorbents. This study is accompanied by a discussion based on the conducted experiments and currently available literature, providing readers with a clearer understanding. Water hyacinth's capacity to absorb macro- and micro-nutrients, nitrogen, and phosphorus makes it a good plant for phytoremediation. The prospect of producing cellulose makes it prospective as a biomass energy source and livestock feeding. Further, it can be transformed into high-cellulose content particles for applications in bioplastics, brake pads, and adsorbents. The current reports regarding education of water hyacinth to student also were added. Finally, issues and suggestions for future development related to the use of water hyacinths are discussed. This study is expected to provide comprehensive knowledge on how to turn invasive water hyacinth plants into valuable products.
Full-text available
As an invasive species, water hyacinths ( Eichhornia crassipes ) are known to progressively proliferate and cause the ecological invasions of aquatic environment. Their incursions not only cause the disappearance of native species but gradually degrades the natural habitats of freshwater regimes. The control and management of these species is laborious task, however, transforming weed into wealth can substantially serve a sustainable approach to reduce the efforts. Therefore, the present study intends to utilise the application of geospatial techniques for mapping the water hyacinths growth in the Deepor beel (wetland) of Assam, India. Sentinel based image analysis has shown that pre-monsoon seasons has encountered massive productivity and area coverage of water hyacinth, whereas in post-monsoon seasons, productivity of water hyacinths reduces to half. Furthermore, i n-situ biomass estimation of the water hyacinths samples same around the productive season has been collected and analysed 6 kg (green biomass) and 1 kg (dry biomass after sun-dried). Finally, this hybrid approach evaluated the production and revenue generation from Moorhen yoga mat (handicraft item) made from the dried water hyacinths. After assuming the actual availability of 50% of total mass yield of water hyacinths, around ~ 0.8 million (8.8 lakhs) yoga mats can be commercially produced within the most productive seasons. The revenue generation from the yoga mat in the domestic and international markets evaluated around US $ 12.79 million (Rs. 105.85 Crore) and US $ 15.99 million (Rs. 132.31 crore), respectively from a single productive season. Thus, applicative intent of this study can boost potential market in Assam, renovate the weed waste of water hyacinth into wealth generation, and sustainably support the livelihoods of the local communities.
Agricultural pollutants known to have harmful impacts on aquatic species and ecosystems include excess levels of plant nutrients (e.g., ammonium nitrate and phosphate from fertilizers) as well as inorganic (e.g., heavy metals) and organic compounds (e.g., pesticides including insecticides and herbicides) commonly associated with global farming practices. This chapter examines the role of phytoremediation in decontaminating these key pollutants of agricultural origins, with a particular focus on the plant species and environmental dynamics which occur in tropical regions. This chapter also includes strategic applications (e.g., terrestrial barrier plantings around sensitive wetlands), which could provide safe, affordable, and environmentally sustainable solutions for reducing the impacts of agricultural practices on tropical wetlands.KeywordsFarmsAgricultural wastewatersWetlandsDecontaminationBarrier plantingsSoils
Full-text available
Many cities in developing countries are facing surface water and groundwater pollution problems. This deterioration of water resources needs to be controlled through effective and feasible concepts of urban water management. The Dublin Principles, Agenda21, Vision21, and the Millennium Development Goals provide the basis for the development of innovative, holistic, and sustainable approaches. Whilst highly efficient technologies are available, the infusion of these into a well-thought out and systematic approach is critical for the sustainable management of nutrient flows and other pollutants into and out of cities. Based on cleaner production principles, three intervention steps are proposed in this paper. The first step is to minimise wastewater generation by drastically reducing water consumption and waste generation. The second step is the treatment and optimal reuse of nutrients and water at the smallest possible level, like at the on-plot and community levels. Treatment technologies recommended make the best use of side products via reuse. Once the first two intervention steps have been employed to the maximum, the remaining waste flows could be safely discharged into the environment. The third step involves enhancing the self-purification capacity of receiving water-bodies (lakes, rivers, etc.), through intervention. The success of this so-called 3-step strategic approach requires systematic implementation, providing specific solutions to specific situations. This, in turn, requires appropriate planning, legal and institutional responses. In fact, the 3-step approach could be applied as an overall approach for waste management, although here the focus is on sewage. This paper offers examples under each step, showing that the systematic application of this approach could lead to cost savings and sustainability.
Full-text available
Metals like Fe, Zn, Cu, Pb, C r & A s in different components ofThane creek were studied during 199 1 -94.The re-sults showed that water had metals higher than the permissible limits except in Cu & Zn.The biotic components allowed accumulation of essential metals Fe, Zn & Cu, whereas they regulated toxic trace metals As. C r & Pb. How-ever lead contents of these components, especially prawn (Metapenaeus rnonoceros) and fish (Mystus gulio and Mugil cephalus) were found almost reaching the permissible limits. Zn had maximum accumulation in the prawn, Cu accu-mulated maximum in polychaetes, whereas, Pb, Fe.As & C r accumulated maximum in phytoplankton.The detritus food chain (sediment + polychaete & prawn +,Fish M. gulio) showed higher bioaccummulation as compared t o grazing food chain (water + phytoplankton + fish M. cephalus).A comparison of metal levels with the data of 1984-85 re-vealed increase in Cu. Zn, Pb (except lowering of Cu in sediment and prawn) suggesting deteriorating status of the creek.
Full-text available
As we approach the next century, more than a quarter of the world's population or a third of the population in developing countries live in regions that will experience severe water scarcity. This paper reports on a study to project water supply and demand for 118 countries over the 1990-2025 period. The nature and geographic focus of growing water scarcity are identified. In the semi-arid regions of Asia and the Middle East, which include some of the major breadbaskets of the world, the ground water table is falling at an alarming rate. There is an urgent need to focus the attention of both professionals and policy makers on the problems of ground water depletion, which must be seen as the major threat to food security in the coming century.
Full-text available
Aquatic plants have potential as feedstuffs in certain nations, but the economics of harvesting and processing would prohibit their direct utilization as a forage in technologically advanced nations. However, nutrient pollution is accelerating rates of eutrophication of natural waters in many areas. Aquatic plants produce large standing crops and accumulate large amounts of nutrients. Systems based on the harvest of aquatic plants have potential application in removing nutrients from effluents and natural waters.
Water Pollution: Causes, Effects And Control Is A Book Providing Comprehensive Information On The Fundamentals And Latest Developments In The Field Of Water Pollution.The Book Is Divided Into 28 Chapters Covering Almost All The Aspect Of Water Pollution Including Water Resources And General Properties Of Water; History Of Water Pollution And Legislation; Origin, Sources And Effects Of Pollutants; Bioaccumulation And Biomagnification; Toxicity Testing And Interaction Of Toxicities In Combination; Water Quality Standards; Biomonitoring Of Water Pollution; Bacteriological Examination And Purification Of Drinking Water; Monitoring And Control Of Pollution In Lakes, Rivers, Estuaries And Coastal Waters; Physical And Biological Structure Of Aquatic Systems; And Structure, Properties And Uses Of Water.Some Important Topics Like Eutrophication, Organic Pollution, Oil Pollution And Thermal Pollution Have Been Discussed In Detail. The Water Pollution Caused By Pesticides, Heavy Metals, Radio Nuclides And Toxic Organics And Inorganic Along With The Water Quality Problems Associated With Water-Borne Pathogens And Nuisance Algae Have Also Been Dealt With Extensively.The Book Covers In Detail The Flow Measurement And Characterization Of Waste Waters In Industries, And Control Of Water Pollution By Employing Various Techniques For Treatment Of Biological And Nonbiological Wastes. The Considerations For Recycling And Utilization Of Waste Waters Have Also Found A Place In The Book. Special Topic Has Also Been Given On Water Pollution Scenario And Water Related Policies And Programmes In India.The Book Shall Be Of Immediate Interest To The Students Of Environmental Science, Life Science And Social Sciences Both At Undergraduate And Postgraduate Levels. People From A Wide Variety Of Other Disciplines Like Civil, Chemical And Environmental Engineering; Pollution Control Authorities; Industries; And Practicing Engineers, Consultants And Researchers Will Also Find The Book Of Great Interest.
Opencast coalmine effluent contains higher concentrations of Cd, Cr, Co, Ni and Pb. Biofiltration of these metals has been demonstrated successfully with the help of aquatic macrophytes i.e., E. crassipes, L. minor and A. pinnata. Experiments revealed E. crassipes reduced highest concentration of heavy metals followed by L. minor and A. pinnata on 20th days retention period. Plant tissue analysis revealed higher accumulation of metals in roots than leaves. Highly significant correlations have been noted between removal of heavy metals in effluent and their accumulation in roots and leaves of the experimental sets. Translocation factor also revealed lower transportation of metals from root to leaves. Reduction in chlorophyll and protein content was noted with the accumulation of heavy metals. N, P and K analysis in plant tissues indicated continuous decrease in their concentration with increasing metal concentration. Negative and significant correlations between metal accumulation and N, P and K concentrations in plant tissues showed adverse effects of heavy metals. Analysis of variance (Dunnett t-test) showed significant results (p < 0.001) for all the metals in different durations.
Wastewater aquaculture has been practiced throughout the world. Conversion of waste into usable resources, environmental protection internalized in the aquaculture procedure and sustainable development are its objectives. Its fundamental principles are holism, harmony, self-resiliency, regeneration and circulation. Its main guiding ecotechniques are series connections of food chains or production chains; parallel connection of originally independent ecosystems to create symbiotic networks; multi-layer and multi-step utilization of materials including products, byproducts and waste; promotion of effective and beneficial circulation; and restoration of ecosystems. This paper focuses on these principles involving several different patterns, demonstrating how these principles and ecotechniques are used in wastewater aquaculture in some pilot case studies in China, including stocking of filter-feeding animals; combining conservation with reasonable utilization of hydrophytes; fishery-cum-husbandry integrated system; duckpond integrated system; treatment and utilization of industrial wastewater by aquaculture.
Water hyacinth(Eichhornia crassipes.(Mart.) Solms) grows abunduntly throughout the tropical and subtropical regions of the world (PENFOUND & EARLE 1948), and is also widely distributed in the southwest regions in Japan(UEKl et ai.1976). Recently, this plant has received attention because of its potential for removal of pollutants when utilized as a biological filtration system(WOLVERTON ~t al. 1978). There are many reports which refer to the removal of mineral nutrients(ORNES et ai. 1975, ROGERS & DAVIS 1972, SHEFFIELD 1967) by aquatic plants, especially water hyacinth from polluted wastes, but few refer to the removal of heavy metals, such as copper(SUTTON et ai. 1971), silver, cobalt, strontium(WOLVERTON et a~.1975a),mercury, Iead(WOLVERTON et al.1975b), cadmium, and nickeI(WOLVERTON et al. 1975c) by water hyacinth from heavy metal-contaminated waste effluents. The purpose of this study was to examine the ability of water hyacinth to remove toxic heavy metals from the metal-containing solution without nutrients in winter. Cadmium, lead, and mercury were chosen for this investigation since they are common toxic metals found in industrial wastewater. Cadmium has not been shown to be essential to the growth of