lead, iron, nickel, mercury, cadmium, zinc, and cobalt (Wang and Yang 2015;
Alvarez et al. 2016) that are harmful for living organism. Certain waste-contributing
manufacturing industries are textile printing, paint, dying, pharmaceutical, leather
tanning, plastics, petroleum, paper, and pulp (Raja and Venkatesan 2010; Hakeem
2015). These inorganic and organic polluted effluents may find their way to surface
water bodies such as lagoon, Table 11.1. Major roles of macrophytes in constructed
wetland Wetland plant part Role Aerial plant tissues Less growth of phytoplanktons
due to light attenuation with reduced wind velocity and risk of settled solid
resuspension with good nutrient storage Aquatic plant tissues Filtering of larger
debris with low current velocity and high rate of sedimentation, less risk of settled
solid resuspension, increased nutrient uptake and aerobic degradation with increased
photosynthetic oxygen excretion Roots and rhizomes Less soil erosion due to
sediment surface stabilization, increased nutrient uptake and organic degradation
due to oxygen release and nitrification with release of antibiotics M. Rastogi and
M. Nandal rivers, lakes, and ponds through canals and become vulnerable to such
pollution (Bhuiyan et al. 2011). One more major contributor is heavy metals being
the most toxic pollutant of groundwater and industrial wastewater. Heavy metals are
persistent and recyclable bio-geochemically and have biological risks (Alves et al.
2012) and so are of particular concern for surface water quality.
(b) Domestic Wastes
Domestic wastes comprise of wastes from the houses that become ultimately a
part of water resources such as rivers, streams, ponds, lakes, and seas and pollute
them severely. They can be categorized further on the basis of nature:
1. Inorganic waste – Nitrate and phosphates being the major component of soaps
and detergents being released in freshwater causing damage to humans, animals,
and plants.
2. Organic waste – Papers, plastic, polythene bags, rotten fruits and vegetables, and
recalcitrant by-products are major causes of organic water pollution.
3. Liquid waste – Dirty and percolating effluents from houses and toxic metalcontaining liquids that leach down and deteriorate the water quality severely
(Hudak 2012).
In addition, domestic sewage comprises of large amount of suspended solids
(such as partially disintegrated particles), colloidal solids, large floating particles of
rags, plastic, etc. (Awadallah and Yousry 2012).
(c) Agricultural Wastes
These wastes hold a major share in wastewater generation by discharging pollutants and sediments into the surface water by periodic storm water. The use of this
wastewater contaminates the crops and causes transmission of diseases to humans.
The agricultural drainage water contains pesticides, fertilizers, and effluent from
manufacturing industry activities and runoff, in addition to sewage effluents and the
presence of decaying plant and animal residues that supply the surface water bodies
with huge quantities of pollutants.
11 Toxic Metals in Industrial Wastewaters and Phytoremediation Using. . .
261
Alvarez et al. 2016) that are harmful for living organism. Certain waste-contributing
manufacturing industries are textile printing, paint, dying, pharmaceutical, leather
tanning, plastics, petroleum, paper, and pulp (Raja and Venkatesan 2010; Hakeem
2015). These inorganic and organic polluted effluents may find their way to surface
water bodies such as lagoon, Table 11.1. Major roles of macrophytes in constructed
wetland Wetland plant part Role Aerial plant tissues Less growth of phytoplanktons
due to light attenuation with reduced wind velocity and risk of settled solid
resuspension with good nutrient storage Aquatic plant tissues Filtering of larger
debris with low current velocity and high rate of sedimentation, less risk of settled
solid resuspension, increased nutrient uptake and aerobic degradation with increased
photosynthetic oxygen excretion Roots and rhizomes Less soil erosion due to
sediment surface stabilization, increased nutrient uptake and organic degradation
due to oxygen release and nitrification with release of antibiotics M. Rastogi and
M. Nandal rivers, lakes, and ponds through canals and become vulnerable to such
pollution (Bhuiyan et al. 2011). One more major contributor is heavy metals being
the most toxic pollutant of groundwater and industrial wastewater. Heavy metals are
persistent and recyclable bio-geochemically and have biological risks (Alves et al.
2012) and so are of particular concern for surface water quality.
(b) Domestic Wastes
Domestic wastes comprise of wastes from the houses that become ultimately a
part of water resources such as rivers, streams, ponds, lakes, and seas and pollute
them severely. They can be categorized further on the basis of nature:
1. Inorganic waste – Nitrate and phosphates being the major component of soaps
and detergents being released in freshwater causing damage to humans, animals,
and plants.
2. Organic waste – Papers, plastic, polythene bags, rotten fruits and vegetables, and
recalcitrant by-products are major causes of organic water pollution.
3. Liquid waste – Dirty and percolating effluents from houses and toxic metalcontaining liquids that leach down and deteriorate the water quality severely
(Hudak 2012).
In addition, domestic sewage comprises of large amount of suspended solids
(such as partially disintegrated particles), colloidal solids, large floating particles of
rags, plastic, etc. (Awadallah and Yousry 2012).
(c) Agricultural Wastes
These wastes hold a major share in wastewater generation by discharging pollutants and sediments into the surface water by periodic storm water. The use of this
wastewater contaminates the crops and causes transmission of diseases to humans.
The agricultural drainage water contains pesticides, fertilizers, and effluent from
manufacturing industry activities and runoff, in addition to sewage effluents and the
presence of decaying plant and animal residues that supply the surface water bodies
with huge quantities of pollutants.
11 Toxic Metals in Industrial Wastewaters and Phytoremediation Using. . .
261