Mukri, B D and Killi, K and Chowdhury, A and Duvvuri, S and Ch, Subrahmanyam
(2016)
Alkali - treated Carbonized Rice Husk for the Removal of
Aqueous Cr(VI).
BioResources, 11 (4).
pp. 9175-9189.
ISSN 1930-2126
Abstract
Rice husk was chemically modified for the
preparation of activated carbon
.
Rice husk
was treated with nitric acid and carbonized at 700
C. After
carbonization, the resulting rice husk char was treated with NaOH at room
temperatur
e.
The
5
M NaOH
-
treated
rice husk ha
d
the
highest surface
area
(
750 m
2
/g
)
. Proximate analysis of activated ca
rbon
confirmed that
NaOH treatment remove
d
silica completely.
T
emperature programmed
decomposition (TPD) graphs
showed
that
the
total gas
contents
(CO and
CO
2
) liberated
by CRH and
H
2
O
-
treated CRH and CRH5M were 2l5
μmol/g, 390 μmol/g
,
and 970 μmol/g, respectively. The adsorption
studies
of the activated carbon
during Cr
(VI) removal from
the
aqueous medium
indicated that CRH5M showed the highest rate of adsorption. The
eff
ect
of adsorbent dosage, Cr
(VI) concentration, pH
,
and temperature were
studied to
determine
the best removal
efficiency. With
a decrease in
pH
from 4.4 to 2, the adsorption capacity increased from 3 mg/g to 25.2 mg/g.
T
he adsorption of
Cr
(VI) followed pse
udo
-
second
-
order behaviour. The
change
s in Gibbs free energy,
enthalpy
,
and entropy
affected by
thermodynamic parameters
were found to be negative, which conf
irmed
that the adsorption of Cr
(VI) on CRH5M is spontaneous, exothermic
, and
favours
low temperatu
re
s
.
[error in script]
IITH Creators: |
IITH Creators | ORCiD |
---|
Ch, Subrahmanyam | https://orcid.org/0000-0002-2643-3854 |
|
Item Type: |
Article
|
Uncontrolled Keywords: |
Rice husk; Surface
area; T
emperature
-
programmed decomposition (TPD); Adsorption study;
1,5
-
D
iphenylcarbazide |
Subjects: |
?? sub5.8 ?? |
Divisions: |
Department of Chemistry |
Depositing User: |
Team Library
|
Date Deposited: |
19 Sep 2016 04:20 |
Last Modified: |
04 Dec 2017 05:48 |
URI: |
http://raiithold.iith.ac.in/id/eprint/2773 |
Publisher URL: |
|
Related URLs: |
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