118
groups for enhancing the adsorption capacities (Cao et al. 2017). Nano-cellulose is
referred as crystallites, nano-fibers or nanocrystals, etc. Wood, sugar beet, potato,
hemp, flax, cotton, algae, and certain bacteria are its typical sources of synthesis
(Hokkanen et al. 2016).
5.3 Heavy Metal Sources and Their Impacts
Heavy metals commonly include metals with specific gravity 5 or higher and finally
metals beyond calcium in the periodic table (Nieboer and Richardson 1980).
Cadmium, cobalt, iron, lead, zinc, chromium, mercury, etc. are considered as toxic
heavy metals (Wagenet et al. 1978). Anthropogenic reasons and increase in industrial activities have enhanced greatly their release in the environment, causing harms
to the flora and fauna. Electroplating, mining, paints and pigments, leather tanning,
textile dyeing, inorganic chemical manufacturing industries, wood treatment, etc.
are the industrial sources of Cr(VI) (Udy 1956; Casarett and Doul 1980), and mining, metal plating, cadmium-nickel battery manufacturing units, smelting, sewage
sludge, etc. are responsible of Cd(II) discharge (Alqudami et al. 2012). Petrochemical,
fertilizer, oil refineries, and automobile industries (Abdel-Halim et al. 2003; Uzu
et al. 2011) release lead, copper, and zinc. Nickel comes mainly from metal plating,
tannery, brewery, boiler pipe, cooking utensil, fertilizer, paper, rubber vulcanization, ceramics, textile, fertilizer, pharmaceutical, and steel production units (Parker
1980, Kim et al. 2007). Chlor-alkali, oil refining, battery, rubber processing, pesticide, thermometer, cosmetics and pharmaceuticals, etc. industries are sources of
mercury contamination (Krishnan and Anirudhan 2002; Namasivayam and
Periasamy 1993).
Heavy metals are water-soluble, and their long persistence in the nature is causing serious health issues (Choi et al. 2009; Stratton 1987). Their toxicity increases
with solubility (Milojkovic et al. 2016). Chromium exists as Cr(III) and Cr(VI) in
aqueous medium with different chemical and biological properties (Ahmad et al.
2005). Cr(VI) is very toxic and is considered as group A human carcinogens by the
Environmental Protection Agency (US-EPA 2006; Cieslak-Golonka 1996; Farhan
et al. 2012; Raji and Anirudhan 1998). All cadmium compounds are potentially
harmful and instigate hypertension, nephritis, and dysfunctions of the nervous system, renal system, birth defects, and itai-itai disease and act as a cumulative poison
(Brower et al. 1997; Dror et al. 2012). Lead and its compounds even at trace level
cause harm to the gastrointestinal track, nervous system, liver, kidney, and brain and
even may cause death. Chronic exposure leads to abortion and neonatal death (Sittig
1981). Excess intake of Cu(II) damages the liver, kidney, and stomach and causes
anemia. It is considered to be carcinogenic and source of neurotoxicity, commonly
known as Wilson’s disease (Baum 1982). Excess zinc intake sets off restlessness,
muscular stiffness, loss of appetite, nausea, infertility, and pancreas problems
(Pahlsson 1989). Nickel causes lung and bone cancer. Headache, dizziness, nausea,
vomiting, and weakness are also related problems (Kadirvelu 1998; Meena et al.
S. Nag and S. Biswas
groups for enhancing the adsorption capacities (Cao et al. 2017). Nano-cellulose is
referred as crystallites, nano-fibers or nanocrystals, etc. Wood, sugar beet, potato,
hemp, flax, cotton, algae, and certain bacteria are its typical sources of synthesis
(Hokkanen et al. 2016).
5.3 Heavy Metal Sources and Their Impacts
Heavy metals commonly include metals with specific gravity 5 or higher and finally
metals beyond calcium in the periodic table (Nieboer and Richardson 1980).
Cadmium, cobalt, iron, lead, zinc, chromium, mercury, etc. are considered as toxic
heavy metals (Wagenet et al. 1978). Anthropogenic reasons and increase in industrial activities have enhanced greatly their release in the environment, causing harms
to the flora and fauna. Electroplating, mining, paints and pigments, leather tanning,
textile dyeing, inorganic chemical manufacturing industries, wood treatment, etc.
are the industrial sources of Cr(VI) (Udy 1956; Casarett and Doul 1980), and mining, metal plating, cadmium-nickel battery manufacturing units, smelting, sewage
sludge, etc. are responsible of Cd(II) discharge (Alqudami et al. 2012). Petrochemical,
fertilizer, oil refineries, and automobile industries (Abdel-Halim et al. 2003; Uzu
et al. 2011) release lead, copper, and zinc. Nickel comes mainly from metal plating,
tannery, brewery, boiler pipe, cooking utensil, fertilizer, paper, rubber vulcanization, ceramics, textile, fertilizer, pharmaceutical, and steel production units (Parker
1980, Kim et al. 2007). Chlor-alkali, oil refining, battery, rubber processing, pesticide, thermometer, cosmetics and pharmaceuticals, etc. industries are sources of
mercury contamination (Krishnan and Anirudhan 2002; Namasivayam and
Periasamy 1993).
Heavy metals are water-soluble, and their long persistence in the nature is causing serious health issues (Choi et al. 2009; Stratton 1987). Their toxicity increases
with solubility (Milojkovic et al. 2016). Chromium exists as Cr(III) and Cr(VI) in
aqueous medium with different chemical and biological properties (Ahmad et al.
2005). Cr(VI) is very toxic and is considered as group A human carcinogens by the
Environmental Protection Agency (US-EPA 2006; Cieslak-Golonka 1996; Farhan
et al. 2012; Raji and Anirudhan 1998). All cadmium compounds are potentially
harmful and instigate hypertension, nephritis, and dysfunctions of the nervous system, renal system, birth defects, and itai-itai disease and act as a cumulative poison
(Brower et al. 1997; Dror et al. 2012). Lead and its compounds even at trace level
cause harm to the gastrointestinal track, nervous system, liver, kidney, and brain and
even may cause death. Chronic exposure leads to abortion and neonatal death (Sittig
1981). Excess intake of Cu(II) damages the liver, kidney, and stomach and causes
anemia. It is considered to be carcinogenic and source of neurotoxicity, commonly
known as Wilson’s disease (Baum 1982). Excess zinc intake sets off restlessness,
muscular stiffness, loss of appetite, nausea, infertility, and pancreas problems
(Pahlsson 1989). Nickel causes lung and bone cancer. Headache, dizziness, nausea,
vomiting, and weakness are also related problems (Kadirvelu 1998; Meena et al.
S. Nag and S. Biswas