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International Journal of Environment Science and Technology
Center for Environment and Energy Research and Studies (CEERS)
ISSN: 1735-1472 EISSN: 1735-1472
Vol. 13, No. 1, 2016, pp. 243-256
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Bioline Code: st16023
Full paper language: English
Document type: Research Article
Document available free of charge
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International Journal of Environment Science and Technology, Vol. 13, No. 1, 2016, pp. 243-256
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Arsenic mitigation by chitosan-based porous magnesiaimpregnated alumina: performance evaluation in continuous packed bed column
Saha, S. & Sarkar, P.
Abstract
Dissolved arsenic in contaminated groundwater
is a major concern on a global scale due to its extreme
toxicity. This paper reports a magnesium oxide-impregnated
mesoporous alumina synthesized using biopolymer
chitosan template. The adsorbent was first characterized by
BET, SEM and EDAX analysis. The packed column performed
effectively over wide range of pH and exhibited a
maximum adsorption capacity of 17.2 mg/g for an input
arsenic concentration of 20 mg/L. The experimental data
fitted well with pseudo-second-order kinetics. Thermodynamic
study on the adsorption phenomena revealed that
arsenic adsorption on the porous adsorbent was spontaneous,
and the process was exothermic. The arsenic sorption
capacity at breakthrough point was greatly dependent
on bed depth. A bed depth service time approach was
adopted to describe the continuous flow system. The column
after exhaustion was regenerated by eluting the bound
arsenate [As(V)] with ~15 bed volume sodium hydroxide
solution. The adsorbent could retain its capacity up to five
cycles of such regeneration. The influence of different
operating conditions such as bed depth, flow rate and initial
arsenic concentration was investigated statistically by the
two-level full-factorial experimental designs to evaluate
optimum operating conditions.
Keywords
Adsorption; BDST model; Breakthrough; Drinking water; Factorial design
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