Experiment, modeling and optimization of liquid phase adsorption of Cu(II) using dried and carbonized biomass of Lyngbya majuscula
Appl Water Sci (2017) 7:935–949
DOI 10.1007/s13201-015-0304-0
ORIGINAL ARTICLE
Experiment, modeling and optimization of liquid phase adsorption
of Cu(II) using dried and carbonized biomass of Lyngbya
majuscula
Deepika Kushwaha1 • Susmita Dutta2
Received: 6 December 2014 / Accepted: 23 June 2015 / Published online: 8 July 2015
Ó The Author(s) 2015. This article is published with open access at Springerlink.com
Abstract The present work aims at evaluation of the
potential of cyanobacterial biomass to remove Cu(II) from
simulated wastewater. Both dried and carbonized forms of
Lyngbya majuscula, a cyanobacterial strain, have been
used for such purpose. The influences of different experimental parameters viz., initial Cu(II) concentration, solution pH and adsorbent dose have been examined on
sorption of Cu(II). Kinetic and equilibrium studies on
Cu(II) removal from simulated wastewater have been done
using both dried and carbonized biomass individually.
Pseudo-second-order model and Langmuir isotherm have
been found to fit most satisfactorily to the kinetic and
equilibrium data, respectively. Maximum 87.99 and
99.15 % of Cu(II) removal have been achieved with initial
Cu(II) concentration of 10 and 25 mg/L for dried and
carbonized algae, respectively, at an adsorbent dose of
10 g/L for 20 min of contact time and optimum pH 6. To
optimize the removal process, Response Surface Methodology has been employed using both the dried and carbonized biomass. Removal with initial Cu(II) concentration
of 20 mg/L, with 0.25 g adsorbent dose in 50 mL solution
at pH 6 has been found to be optimum with both the
adsorbents. This is the first ever attempt to make a comparative study on Cu(II) removal using both dried algal
biomass and its activated carbon. Furthermore, regeneration of matrix was attempted and more than 70% and 80%
of the adsorbent has been regenerated successfully in the
& Susmita Dutta
1
Department of Earth and Environmental Studies, National
Institute of Technology Durgapur, Durgapur 713209, India
2
Department of Chemical Engineering, National Institute of
Technology Durgapur, Durgapur 713209, India
case of dried and carbonized biomass respectively upto the
3rd cycle of regeneration study.
Keywords Lyngbya majuscula Copper Adsorbent
Response Surface Methodology Optimization
Regeneration
Introduction
Heavy metal pollution of aquatic system is a serious
environmental problem, resulting from rapid industrialization. Due to their non-biodegradable and recalcitrant
nature, they accumulate in the environment causing a
serious threat to human health and ecological systems
(Papageorgiou et al. 2008). As per the list published by
United States Environmental Protection Agency (USEPA)
in 1978, the most hazardous metals listed are antimony,
arsenic, beryllium, cadmium, copper, lead, mercury, nickel,
selenium, silver, thallium and zinc. According to USEPA,
maximum permissible limit of copper in drinking water
and industrial wastewater is 1.0 and 3.0 mg/L, respectively. Though copper, a heavy metal, is essential in minute
amount (3 mg/day) for different biochemical pathways in
human body, it becomes toxic when its concentration in
drinking water exceeds the permissible limit. Copper is
found in effluent coming from different industries such as
electroplating, coal, tanning, smelting, copper wire mills,
insecticides, fungicides, etc. The presence of Cu(II) ions
above permissible limit is extremely toxic to living
organisms. It is usually known to be deposited in liver,
pancreas, brain and may produce gastrointestinal catarrh
(Gupta et al. 2006). Conventional methods such as chemical precipitation, ion exchange, chemical oxidation and
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Appl Water Sci (2017) 7:935–949
electrochemical treatment have been used to reduce heavy
metals from polluted water but these are expensive, less
effective, inefficient at low metal concentration i.e., below
100 mg/L and produce toxic sludge (Yilmazer and Saracoglu 2009).
Adsorption process is recognized as an effective and
economic method for the abatement of heavy metals from
wastewater (Fu and Wang 2011). Using microorganisms as
sorbent is a new and very promising technology for
wastewater treatment. The major advantages of biosorption
over conventional methods are low cost, minimization of
sludge, highly efficient at low metal ion concentration and
regeneration of biosorbent. Biosorption occurs by physicochemical interaction between the cell surface and metal
ions and hence reported as metabolically independent
mechanism while bioaccumulation is metabolically
dependent mechanism (Flouty and Estephane 2012). Bacteria, fungi, yeast and algae are potential metal biosorbent
and among these the cyanobacterial populations have been
found as more promising due to their simple nutrient
requirements, larger biomass production and generally
non-toxic and eco-friendly nature (Kiran and Kaushik
2008). Phycoremediation of heavy metals is an emerging
technology in which macroalgae or microalgae are used to
remove or transform the pollutants. Algae have high metal
binding capabilities due to the presence of negative charges
on the surface of their cell walls (Pittman et al. 2011).
Dried algal biomass and its activated carbon are used for
passive uptake of heavy metals while living cells take part
actively in biosorption and bioaccumulation processes. As
maintenance of living alga at higher metal ion concentration is a challenging job, the present study deals with
biosorption using dried and carbonized algal biomass. The
efficiency of this process is dependent on different
parameters viz., metal ion concentration, adsorbent dose,
adsorbent size and solution pH (Das et al. 2008). Hence,
optimization of these process parameters is mandatory
from proper bioreactor operation perspectives. The conventional technique for the optimization of a multivariable
system usually defines one factor at a time (Sahu et al.
2009). Response Surface Methodology (RSM) can be used
to overcome the problems associated with the conventional
method for optimization of removal of Cu(II). RSM is a
collection of mathematical and statistical techniques useful
for developing, improving and optimizing processes (Silva
et al. 2004; Ravikumar et al. 2006, 2007; Karacan et al.
2007). Though a number of studies have been done to
optimize chemical processes using RSM, its application in
the field of phycoremediation using two different forms of
algae (dried and carbonized) is probably a novel approach.
East Kolkata Wetland (EKW) is a biodiversity rich
region (Kundu et al. 2008). Different industries like paints,
electroplating, and battery discharge their waste into the
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ponds of wetland. Wastes of these industries act as source
of different metals like chromium, copper, etc. and phytoplankton found in this wetland area are highly resistant to
these metals. In the present work, the cyanobacterium
strain Lyngbya majuscula, collected from EKW site, has
been used for sorp (...truncated)
