SUPPLEMENTARY MATERIAL
Table S1. HPLC retention times (min) of NoA and MY10 at initial incubation time (t0)
and after 24 and 48 h of biological reaction, in the presence and absence of AC0, and of
the standards m-phe, p-phe and 5-ASA (products of biological reduction).
t0
Compound
No AC
After 24h
AC0
No AC
AC0
After 48h
No AC
AC0
o-NoA
12.2
5.4
N.d.
m-NoA
10.1
5.1
N.d.
p-NoA
8.6
4.9
N.d.
MY1
4.6
3.8; 10.0
m-phe
5.1
N.d.
N.d.
p-phe
4.9
N.d.
N.d.
5-ASA
3.8
3.8
3.8
3.8; 10.1; 5.1
3.8; 5.1*
N.d. – not determined; (*) residual amount, as observed in figure 5B.
Characterization of Carbon Materials
Compared with the other CM prepared, AC samples are characterized by the high
volume of microporous and a higher surface area: SBET for AC samples is circa the
double of the CX and triple of the CNT (table S2). The lower S BET of CNT and,
consequently, being equal to its Smeso, as compared with other CM samples, is due to the
inexistent microporous. On the other hand, Smeso is higher for CX and CNT, which is
related with the low amount (CX) or inexistence (CNT) of microporous. The main
differences among the CX, prepared at different initial pH, are in the average mesopore
diameter. The CX prepared at pH 5.45, CXB, has the largest mesopore size (dBJH = 24.4
and 3.2 nm for CXB and CXA, respectively). Contrary to the CX samples that have
cylindrical pores, the mesoporosity of the CNT sample results from the free space in the
CNT bundles, with a pore size distribution between 10 and 24 nm (Orge et al., 2012).
Tessonnier et al. (2009) characterized this material as having an average inner and outer
diameters of 4 and 10 nm, respectively.
Surface oxygen groups on CM decompose upon heating, releasing CO and/or CO2 at
different temperatures, allowing to identify and to estimate the amount of oxygenated
groups (table S3).
As previously reported by our group (Pereira et al., 2010), according to the TPD
analysis higher CO and CO2 release is obtained in sample ACHNO3. Indeed, liquid
oxidation with HNO3 of AC0 increases the amount of surface oxygen-containing
groups, carboxylic, anhydrides and lactones groups. These acidic groups are responsible
for the high acidity and the lower pHpzc value obtained for sample ACHNO3 (pHpzc=2.7).
On the other hand, thermal treatments at high temperature produce materials with low
amount of oxygen containing groups and high basicity, resulting mainly from the
ketonic groups remaining on the surface, from the low amount of acidic groups, and
from the delocalized π-electrons on the carbon basal planes (Gonçalves et al., 2010).
These electrons are responsible for the high basicity of the ACH2 sample (pHpzc=10.4).
CNT sample presents lower oxygen-containing surface groups, especially CO releasing
groups, which explain the neutral pHpzc (Gonçalves et al., 2010).
Table S2. Textural characterization of the tested CM (Pereira et al., 2010; Pereira et al.,
2014; Orge et al., 2012).
SBET
Smeso
Vμpores
dBJHa
(m2 g-1)
(m2 g-1)
(cm3 g-1)
(nm)
AC0
1032
138
0.382
-
ACHNO3
893
102
0.346
-
ACH2
987
129
0.377
-
CXA
540
168
0.192
3.2
CXB
566
233
0.165
24.4
CNT
331
331
0
-
Sample
a
Average mesopore diameter obtained by the Barret, Joyner and Halenda (BJH) method applied to the
desorption isotherm.
Table S3. Chemical characterization of tested CM samples (Figueiredo, 2013; Pereira
pHpzc
(μmol g-1)
quinones
Carbonyl/
(μmol g-1)
Phenols
(μmol g-1)
Lactones
(μmol g-1)
Anhydrides
(μmol g-1)
Carboxylic acids
(μmol g-1)
COb
CO2a
Sample
(μmol g-1)
et al., 2010, Pereira et al., 2014; Orge et al., 2012; Tessonnier et al., 2013).
AC0
243
814
110
79
54
428
307
8.4
ACHNO3
1103
2402
723
222
158
948
1232
2.7
ACH2
59
590
48
0
11
249
341
10.8
CNT
25
478
n.d.c
n.d.c
n.d.c
n.d.c
n.d.c
7.0
a
Amounts of CO and CO2 released, obtained by integration of the areas under TPD spectra.
Mass percentage of oxygen on the surface, obtained from TPD data assuming that all the surface oxygen
is released as CO and/or CO2.
C
Not determined.
b
Table S4. Previously reported results on nitrocompounds chemical and biological
reduction, either in the absence or presence of redox mediators, comparison with the
present work.
Treatment
Redox
Compounds
Results
System
Reference
Mediator
32%, 56%, 52% and 70%
of reduction within 24h at
rate 0.07 h-1, 0.26 h-1, 0.14
h-1 and 0.057 h-1
None
for o-, m-, p- NoA and
Batch assays
MY1, respectively
with non1 mmol L-1 o-, m-, padapted
This work
NoA and MY1
anaerobic
Total reduction in 12h,
granular biomass
4h, 5h and 24h, for o-, m-,
0.1 g L-1
AC0
p- NoA and MY1 at rate
0.15 h-1, 1.14h-1, 1.05 -1
and 0.161 h-1, respectively
(adsorption <10%)
Chemical
Nitrobenzene
reduction by
sulphides in
aqueous
0.3gL-1
Carbon
(Yu
et al.,
0.0367 h-1
2011)
Black CB
solutions
~20% within 15 days for
None
4NP and ~50% within 1
0.5 mmol L-1 of 4Chemical
day, for 3CNB
(Amezquita-
~90% within 15 days for
Garcia et al.,
4NP and ~85% within 1
2013)
nitrophenol (4.NP)
reduction by
or 3Na2S in aqueous
chloronitrobenzene
solutions
(3CNB)
-1
1 gL
Activated
day, for 3CNB
carbon fibers
(adsorption <20%)
Very low extent of
Chemical
0.08 mmol L-1
reduction by
nitrobenzene
Na2S in aqueous
None
reduction
r=7.83 × 10–5 h–1
0.005 gL-1
solutions
(Fu
and Zhu,
2013)
~70% within 7 days
Graphene
oxide (GO)
r=7.77 × 10–3 h–1
~14 % over 72 h
None
r=0.0016 h−1
Chemical
0.5 gL-1 of
reduction by
Black
sulphides in
carbons from
aqueous
rice (R-BC),
solutions
wheat straw
~75 % over 72 h
(Gong et
-1
0.275 mmol L
nitrobenzene
al.,
2014)
R-BC > W-BC > C-BC:
(W-BC) and
r = 0.0186, 0.0063, and
corn (C-BC)
0.0051 h-1, respectively
straw ashes
MO1:
UASB
None
MO1 reduction occurred
(Donlon
et al.,
0.35 mmol L-1
bioreactors:
only with adapted
R1without co-
biomass:
1997)
in R2 and 0.18
substrate, R2
mmolL-1
R1 performance slowly
with glucose and
dropped over time, failing
in R3
R3 with VFA
completely by day 50
Anaerobic
In R2, 95% and in R3,
granular sludge
91% MO1 reduction
adapted with
(HRT of 8h)
increasing MO1
concentrations
during 75 days
Table S5. VFA consumption in biological assays for the reduction of the azo dye Acid
Orange 10 (AO10) (unpublished data) in the absence and presence of 0.1 g L-1 of AC0
or CNT.
Experimental Assay
Biomass+AO10
Biomass+AO10+AC0
Biomass+AO10+CNT
Incubation
Time
(h)
0
8
24
0
8
24
0
8
24
VFA concentration (mM)
Acetic
Propionic
Butyric
Acid
Acid
Acid
3.37
11.93
11.62
3.49
9.42
11.38
0.76
7.09
11.10
3.30
12.09
12.00
3.34
9.73
11.96
0.60
6.68
11.65
3.63
11.91
11.63
4.45
10.16
11.92
2.73
7.75
11.37
A
B
C
D
E
F
Figure S1. Photography of magenta complex formed from the reaction of Fe2+ (resulted
from the reduction by AC0) with ferrozine (duplicate experiments): (A and B) – 0.1 g L1
AC0 and (D and E) – 1.0 g L-1 AC0, previously biologically reduced in the absence and
presence of BES, respectively. C and F, are the controls with AC0 (0.1 and 1.0 g L-1,
respectively) incubated in the same conditions of biotic experiments, but without
biomass.