16 Fantastic Floating Weeds and How to Use Them
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and Indonesia water hyacinth was reported to be used as feedstock for pigs, fishes,
ducks, and other non-ruminants after sun drying. Oguniade et al. (1988), reported
that after drying the protein mineral and vitamin content in water hyacinth increases
and the dry matter had less fiber (33%) and elevated crude protein (18%). Healthy
weight is seen to be retained when water hyacinth is mixed with fodder crops, e.g.,
Ctenopharyngodon idella grass up to 100%. It further decreased the protein efficiency ratio. Water hyacinth is also extensively used as fish feed. It has been used
after removing moisture to feed channel catfish fingerlings to improve their production. When chemical control was used to eradicate the weed, the dead decayed matter
released compounds in the water that were beneficial for both fishes and phytoplanktons (Jianbo et al. 2008). Water hyacinth is also enriched with calcium (~2%) and
can strengthen the egg shells and increased total weight of the egg when used as duck
feed. Furthermore, the digestion rate and absorption of other nutrients were found to
have improved in ducks.
16.2.5 As Biosorbent
Water hyacinth comprises certain binding sites and functional groups that can bind
cationic metals and anionic complexes to its matrix. The root portion of the plant acts
as an excellent metal sorbent and the overall plant is considered as a better sorbent
than yeast Candida parapsilosis, bacterium Mycobacterium phlei, and fungus Rhizopusoryzae strains or even better than the acacia bark (Priya and Selvan 2017). Zheng
et al. (2009) utilized dried water hyacinth roots for Cu (II) bio sorption from aqueous
media. Water hyacinth was converted to ash and then used as a sorbent and hyper
accumulator for uptake of Pb
2+ , Zn
2+ , Cr
6+ , Zn
2+ , and Ni
2+ (Mahmood et al. 2010). In
most of the cases, metal absorbed by the plant could be desorbed and recovered after
subjecting to proper treatment. A significant concern for water hyacinth to be commercially used as biosorbent is the regeneration capacity of its biomass and ability to
recover the heavy metals uptake. Metal recovery is very essential, mainly if precious
trace metals are involved in the process and cheaper desorption techniques are also
crucial because formation of the biomass matrix is expensive (Mahamadi 2011). The
more the sorbent efficiency and greater the absorption capacity with multiple reuse,
more is its economic value. The absorption depends on many criteria viz., pH, dose,
contact time, and temperature. Analysis of the rapid spread of water hyacinth and
problems related to it can be compensated by involving them in biosorption.
16.2.6 Biogas Production
Biogas constitutes various gases mainly comprising of methane (CH 4 ) and trace
amounts of carbon dioxide (CO 2 ), carbon monoxide (CO), hydrogen (H 2 ) and nitrogen (N 2 ) that are produced after the disintegration of organic substances that occurs
373
and Indonesia water hyacinth was reported to be used as feedstock for pigs, fishes,
ducks, and other non-ruminants after sun drying. Oguniade et al. (1988), reported
that after drying the protein mineral and vitamin content in water hyacinth increases
and the dry matter had less fiber (33%) and elevated crude protein (18%). Healthy
weight is seen to be retained when water hyacinth is mixed with fodder crops, e.g.,
Ctenopharyngodon idella grass up to 100%. It further decreased the protein efficiency ratio. Water hyacinth is also extensively used as fish feed. It has been used
after removing moisture to feed channel catfish fingerlings to improve their production. When chemical control was used to eradicate the weed, the dead decayed matter
released compounds in the water that were beneficial for both fishes and phytoplanktons (Jianbo et al. 2008). Water hyacinth is also enriched with calcium (~2%) and
can strengthen the egg shells and increased total weight of the egg when used as duck
feed. Furthermore, the digestion rate and absorption of other nutrients were found to
have improved in ducks.
16.2.5 As Biosorbent
Water hyacinth comprises certain binding sites and functional groups that can bind
cationic metals and anionic complexes to its matrix. The root portion of the plant acts
as an excellent metal sorbent and the overall plant is considered as a better sorbent
than yeast Candida parapsilosis, bacterium Mycobacterium phlei, and fungus Rhizopusoryzae strains or even better than the acacia bark (Priya and Selvan 2017). Zheng
et al. (2009) utilized dried water hyacinth roots for Cu (II) bio sorption from aqueous
media. Water hyacinth was converted to ash and then used as a sorbent and hyper
accumulator for uptake of Pb
2+ , Zn
2+ , Cr
6+ , Zn
2+ , and Ni
2+ (Mahmood et al. 2010). In
most of the cases, metal absorbed by the plant could be desorbed and recovered after
subjecting to proper treatment. A significant concern for water hyacinth to be commercially used as biosorbent is the regeneration capacity of its biomass and ability to
recover the heavy metals uptake. Metal recovery is very essential, mainly if precious
trace metals are involved in the process and cheaper desorption techniques are also
crucial because formation of the biomass matrix is expensive (Mahamadi 2011). The
more the sorbent efficiency and greater the absorption capacity with multiple reuse,
more is its economic value. The absorption depends on many criteria viz., pH, dose,
contact time, and temperature. Analysis of the rapid spread of water hyacinth and
problems related to it can be compensated by involving them in biosorption.
16.2.6 Biogas Production
Biogas constitutes various gases mainly comprising of methane (CH 4 ) and trace
amounts of carbon dioxide (CO 2 ), carbon monoxide (CO), hydrogen (H 2 ) and nitrogen (N 2 ) that are produced after the disintegration of organic substances that occurs