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T. Rasool and W. Baba
chemical, neurological and physical impact on humans (Mehta and Gaur 2014).
Unlike organic pollutants which are biodegradable, heavy metals pose a serious
challenge for their removal or remediation from effluents and wastewaters. The focus
of this study are two heavy metals Zn(II) and Ni(II), which owe their origin mostly
from automobile, petroleum, pulp and paper, steel, organic and inorganic chemical,
fertilizer, mining, metal electroplating and steel power plants (Mali et al. 2014;
Srivastava et al. 2007). The permissible concentration limit set by World Health
Organization (W.H.O) for nickel discharge is 0.5 mg/l for surface water and 0.05 mg/l
in drinking water while that for zinc, it is 5 mg/l and 0.05 mg/l, respectively (WHO
2004).
Adsorption has been potentially proven as one of the non destructive and efficient
methods for removal of heavy metals from effluents and waste water (Mali et al.
2014). The recent trend in the removal of heavy metals through adsorption has been
the application of various biomass and clay based composites and these composites
have proven both effective, efficient and eco-friendly in nature (Mali et al. 2014; Ngah
et al. 2011; Rashid et al. 2016). Biomasses based on algae, fungi, bacteria, seaweeds
and other aquatic and terrestrial plankton have been often used for the removal of
heavy metals based on adsorption (Elangovan et al. 2008). On the other hand investigations on clays such as monti-morillonites, kiolinites, esmectities for adsorption
have shown promising tendencies and efficiencies for removal of heavy metals from
wastes due to their diverse and dynamic characteristics primarily the overall negative
charge on its surface which facilitates the removal of positively charged metal ions
along with physical and chemical stabilities and high superficial area. Bentonite composed of monti-morillonites contains swelling clays along with MgO, Fe 2 O 3 , Na 2 O,
SiO 2 , Al 2 O 3 , and K 2 O and its composites with various biomasses have emerged as
promising and excellent agents for removing heavy metals from waste water (Rashid
et al. 2016). In view of promising adsorption characteristics shown by both the dead
algal biomass and bentonite, a nanocomposite of algae-sodium bentonite (ABC) was
synthesized and evaluated for the removal of Ni(II) and Zn(II) from aqueous media.
2 Materials and Methodology
Analytical grade sodium-bentonite (Sigma Aldrich) was used for synthesis of composite bioadsorbent. Besides analytical grade nickel nitrate, zinc nitrate, sodium
hydroxide, hydrochloric acid, sodium chloride, calcium chloride, iron chloride were
used. Deionized water (ASTM Type-II, Rions India) with total chlorides less than
3 ppm, was used for all the experimental procedures. The samples of algae were collected from popular Dal Lake in Srinagar of Jammu & Kashmir (India). The samples
were collected using standard procedure and strains were identified using inverted
microscopy and identified as Spirogyra species. The microscopic view of the algal
strain is presented in Fig. 1.
T. Rasool and W. Baba
chemical, neurological and physical impact on humans (Mehta and Gaur 2014).
Unlike organic pollutants which are biodegradable, heavy metals pose a serious
challenge for their removal or remediation from effluents and wastewaters. The focus
of this study are two heavy metals Zn(II) and Ni(II), which owe their origin mostly
from automobile, petroleum, pulp and paper, steel, organic and inorganic chemical,
fertilizer, mining, metal electroplating and steel power plants (Mali et al. 2014;
Srivastava et al. 2007). The permissible concentration limit set by World Health
Organization (W.H.O) for nickel discharge is 0.5 mg/l for surface water and 0.05 mg/l
in drinking water while that for zinc, it is 5 mg/l and 0.05 mg/l, respectively (WHO
2004).
Adsorption has been potentially proven as one of the non destructive and efficient
methods for removal of heavy metals from effluents and waste water (Mali et al.
2014). The recent trend in the removal of heavy metals through adsorption has been
the application of various biomass and clay based composites and these composites
have proven both effective, efficient and eco-friendly in nature (Mali et al. 2014; Ngah
et al. 2011; Rashid et al. 2016). Biomasses based on algae, fungi, bacteria, seaweeds
and other aquatic and terrestrial plankton have been often used for the removal of
heavy metals based on adsorption (Elangovan et al. 2008). On the other hand investigations on clays such as monti-morillonites, kiolinites, esmectities for adsorption
have shown promising tendencies and efficiencies for removal of heavy metals from
wastes due to their diverse and dynamic characteristics primarily the overall negative
charge on its surface which facilitates the removal of positively charged metal ions
along with physical and chemical stabilities and high superficial area. Bentonite composed of monti-morillonites contains swelling clays along with MgO, Fe 2 O 3 , Na 2 O,
SiO 2 , Al 2 O 3 , and K 2 O and its composites with various biomasses have emerged as
promising and excellent agents for removing heavy metals from waste water (Rashid
et al. 2016). In view of promising adsorption characteristics shown by both the dead
algal biomass and bentonite, a nanocomposite of algae-sodium bentonite (ABC) was
synthesized and evaluated for the removal of Ni(II) and Zn(II) from aqueous media.
2 Materials and Methodology
Analytical grade sodium-bentonite (Sigma Aldrich) was used for synthesis of composite bioadsorbent. Besides analytical grade nickel nitrate, zinc nitrate, sodium
hydroxide, hydrochloric acid, sodium chloride, calcium chloride, iron chloride were
used. Deionized water (ASTM Type-II, Rions India) with total chlorides less than
3 ppm, was used for all the experimental procedures. The samples of algae were collected from popular Dal Lake in Srinagar of Jammu & Kashmir (India). The samples
were collected using standard procedure and strains were identified using inverted
microscopy and identified as Spirogyra species. The microscopic view of the algal
strain is presented in Fig. 1.