National Biosolids Odors Research Meeting @ Bucknell University, June 13, 2002
Odor Research at Virginia Tech, CEE
D. Glindemann, J. Novak
Dietmar Glindemann, Dglindem@vt.edu
Virginia Tech, 418 Durham Hall (0246)
Blacksburg, Virginia, 24061, USA
ph 001-540-231-2146, fx 001-540-231-7916
e-mail dglindem@vt.edu www.glindemann.net
Analytical developments
- Static headspace incubation standard
- Chemical odor analysis (GC, IC)
- Olfactory analysis of “sticky” odor
Odor Mechanisms
- Do polymer flocculants cause odor?
- Odor production by sludge liming
- Odor problems caused by centrifuges
Analytical Service
Cooperation:
- WSSC
- Bucknell University
- Private Sector
Sludge Incubation Standard in closed PET
polymer bottles
Gas permeability of Beverage bottles
made of PET(E)
Gas Permeability of Plastics
Permeability
LDPE
(cc/100 in2 /mil/day/atm)
N2
180
O2
500
CO2
2700
HDPE
PP
PS
PET
PVC
42
185
580
44
190
650
50
330
1160
0.8
5
15
2
4
4
Olfactometer
For “sticky” analytes (fatty acids, amines, indole, skatole)
For on-line analysis of headspace in contact with sludge
Calibrated by butanol-1 (40 ppm(v) = 1 European
Olfactory Unit OU)
Cryo-Enrichment of Odor for GC-MS analysis
Net analysis time (sampling + GC): 15 min
(SPME: 1 hour)
Chemical classes analyzable: unlimited
(FPD only sulfur, NPD only nitrogen)
Detection limit similar to FPD, NPD due to enrichment and extremely narrow peaks
Certified pressurized gas standards of odor
compounds
GC-MS – selective, sensitive, universal
Ion-chromatograms of
4 organosulfurs, chloroform, trimethylamine and acetone,
headspace of limed digested sludge
GC-MS of Aromates and Aromatic Amines
in sludge headspace
GC-MS analysis of sulfides in
Headspace of digested sludge
Fast GC-MS of CH4, O2, CO2 in headspace
of digested sludge
Precision of Headspace analysis,
cryofocussion and GC-MS
Methane thiol (47)
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00
Dimethylsulfide (62)
Carbon disulfide (76)
Disulfide, dimethyl (94)
Acetone (58)
Si
gm
a
Av
er
ag
e
5
4
3
2
Total Sulfur
1
Concentration / (mg/m3)
Precision of standard injection. Sample is standard MS/DMS in Tedlar bag.
200.0
Precision of sludge headspace injection. Sample is sludge/headspace bottle
Matt-7 (3d)
Methane thiol (47)
Dimethylsulfide (62)
150.0
Carbon disulfide (76)
100.0
Disulfide, dimethyl (94)
Acetone (58)
50.0
Total Sulfur
Si
gm
a
Av
er
ag
e
5
4
3
2
0.0
1
Concentration / (mg/m3)
Number of injection, average, and standard
deviation sigma
Number of injection, average, and standard
deviation sigma
250.0
200.0
Methane thiol, 5 times
150.0
Methane thiol, 1 times
100.0
50.0
0.0
1 and 2
17 and
18
21 and
22
29 and
30
32 and
34
37 and
38
Dimethylsulfide, 5 times
60.0
Dimethylsulfide, 1 times
41 and
42
43 and
44
41 and
42
43 and
44
40.0
20.0
0.0
1 and 2
17 and
18
21 and
22
Concentration / (mg/m3)
25 and
26
29 and
30
32 and
34
80.0
60.0
40.0
20.0
0.0
37 and
38
Disulfide, dimethyl, 5 times
Disulfide, dimethyl, 1 times
1 and 2 17 and
18
Concentration / (mg/m3)
25 and
26
80.0
Concentration /
(mg/m3)
Concentration / (mg/m3)
Concentration / (mg/m3)
Influence of sampling schedule of bottles on concentration at the 5th day
- 5 times: samples taken on 5 consecutive days
- 1 times: sample taken only on 5th day.
21 and
22
25 and
26
29 and
30
32 and
34
37 and
38
41 and
42
43 and
44
29 and
30
32 and
34
37 and
38
41 and
42
43 and
44
8.0
Carbon disulfide, 5 times
6.0
Carbon disulfide, 1 times
4.0
2.0
0.0
1 and 2 17 and
18
21 and
22
50.0
Acetone, 5 times
40.0
Acetone, 1 times
25 and
26
30.0
20.0
10.0
0.0
1 and 2
17 and
18
21 and
22
25 and
26
29 and
30
32 and
34
37 and
38
41 and
42
43 and
44
Influence of oxygen exclusion / aeration on
headspace odor
Re-Aeration of anaerobicly stored sludge cake DS 906
Conc. µg S/m3 (ppb weight/volume)
Methane
thiol
DMS
CS2
DMDS
Re-aerated for 1 day after 13th day of anaerobical storage
Centrifuge DS 906
14181
12067
ND
Horicontal Conveyor
1986
1585
215
Vertical Conveyor
643
970
ND
No Air Exposure, after 14 days of anaerobical storage
Centrifuge DS 906
510
835
369
Horicontal Conveyor
372
427
278
Vertical Conveyor
ND
502
143
3074
691
931
ND
ND
ND
Effect of water addition on WAS cake odor
Effect of water addition on time course of Organosulfur in WAS cake.
water added on day 2 of incubation,
compared to dry cake
Methane thiol
200.00
Dimethylsulfide
Carbon disulfide
150.00
Disulfide, dimethyl
Total Sulfur
100.00
50.00
Day of incubation
y)
5
(d
r
y)
4
(d
r
y)
3
(d
r
y)
(d
r
2
1
(d
r
y)
)
(3
d
>w
at
er
)
er
5
4
(2
d
>w
at
er
>w
at
(1
d
3
(9
0
m
in
>w
at
er
)
)
0.00
2
Concentration / (mg/m3)
250.00
Effect of Liming on Sulfur odor
5
Concentration / (mg S /m3
5
4
4
Methane thiol
3
Dimethylsulfide
3
Carbon disulfide
2
Disulfide, dimethyl
2
Total S
1
1
0
-0.1
+0.5
+2
+24
time / hours … weeks
+48
+6 weeks
Partitioning of TMA between
liquid (sludge or water) and headspace
Effect of dilution on the headspace
concentration of TMA (volume of bottle 710
ml, 10 mg TMA added)
1000000
100000
10000
Total volume of liquid in
bottle
Concentration TMA-N in
headspace, mg/m3
Partition coefficient TMA
between sludge/gas
1000
100
10
1
TMA + TMA + TMA + TMA + TMA + TMA +
cake + cake + cake + water water water
water water water
Cationic polymer flocculant bio-degradation
and TMA formation (5 day incubation)
Mass of TMA-N in fermentor
/ mg
5 day flocculant Brand 3 microaerobic fermentation by digested
sludge cake
10
9
8
7
6
5
4
3
2
1
0
Flocculant-TMA added
Total free TMA
4500
1500
500
150
No
flocculant
+ sludge
1500, no
sludge
Polymer dosage / ppm (weight polymer /weight sludge)
Mass of TMA-N in fermentor
/ mg
5 day flocculant Brand 3 aerobic fermentation by low biosolid
WAS sludge
10.00
Flocculant-TMA added
Total free TMA
8.00
6.00
4.00
2.00
0.00
4500
1500
500
150
No
flocculant
+ sludge
1500, No
sludge
Polymer dosage / ppm (weight polymer /weight sludge)
Mass of TMA-N in fermentor
/ mg
5 Polymer brands: 5 day microaerobic fermentation by high biosolid
digested sludge, Polymer dosage 3333 ppm (weight)
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Flocculant-TMA added
Total free TMA
Brand 1
Brand 2
Brand 3
Brand 4
Polymer Brand Name
Brand 5
No flocculant
+ sludge
Balancing of Trimethylamine (TMA) between
headspace and liquid using partition coefficient
liquid/vapor of 300
5 day flocculant Brand 3 anaerobic incubation using low biosolid WAS
sludge
No dewatering to exclude protein effects,
Volume of headspace: 610 ml, Volume of liquid: 100 ml
10
Mass of TMA-N / mg
1
0.1
0.01
0.001
Flocculant-TMA added
Total free TMA (liquid + headspace)
Headspace free TMA
0.0001
0.00001
00
45
00
15
0
50
No
e
ge
dg
d
u
u
l
sl
+s
o
t
N
0,
l an
u
0
c
5
c
1
flo
0
15
Polymer dosage / ppm (weight polymer /weight
sludge)
Ion-chromatogram of trimethylamine
(CS 16 column, 77oC, eluent 15% Acetone, 25 mM MSA)
Ion chromatography analysis of
trimethylamine (TMA) in dissolved form in
water extracts of different sludge and
sludge cake
(D. Glindemann and Chris Mueller)
Sludge origin
Polymer flocculant
added?
Laboratory treatment
Digested sludge
No
WAS sludge
Raw sludge sediment,
Gravity thickener,
Digested sludge cake
Digested sludge cake
Digested sludge cake
Digested sludge cake
WAS sludge cake,
centrifuge
Blend sludge, Gravity
thickener + DAF
thickener
WAS sludge cake, DAF
thickener
No
No
water added, centrifuged, fugate
analyzed
centrifuged, fugate analyzed
centrifuged, fugate analyzed
YES
YES
YES
YES
YES
GT without polymer
DAF with Polymer
YES
No lime
1% lime added
2% lime added
5% lime added
Neutral extract (Water added,
centrifuged, analyze fugate)
Extract (water added, centrifuged,
fugate treated with 1N HCl and
analyzed after 24h)
Extract (water added, centrifuged,
fugate treated with 1N HCl and
analyzed after 24h)
Conc.
TMA,
mg/l
n.d.
n.d.
0.6
46.0
47.2
47.2
48.5
6.2
5.6
18.0
Su
lfi
d
e
(0
.
09
g
N
*H
2O
ve
r
im dos
um e
4
U do 0 g
nd se pm
er
do 25
se gp
18 m
gp
Be
m
fo
Ve re c
r ti o n
ca
v
l C eyo
on r
ve
yo
r
pt
O
C
0
on
/ 2 .1
p
00 d tro
g /p d l
w
et i ron
sl
C
ud
on
ge
t
r
Ad ol
)
dt ( 1
00
io
Ad n o
g
dt f 1 ca
k
io
0
n
m e)
of
l
20 wa
1
t
m er
da
l
y
w
6
a
at
da na
er
e
y
10 s a r ob
da na ic s
ys ero to
an bic rag
ae
s e
ro tor
ag
bi
c
st e
or
ag
e
aS
O
Weighing different factors affecting sludge odor
as:
Polymer dosage
Mechanical shear
Addition of chemicals
Effect of dilution with water
Time of anaerobic storage
(Methyl mercaptane)
1000000
100000
10000
1000
100
10
1
0
0
Odor chemistry of liming in sludge

2 CH3SH + ½ O2
(low odor threshold)
CH3SSCH3 + H2O
(high odor threshold)
Dimerisation is catalysed by lime and amines
2 CH3SH + Ca(OH)2 
2 CH3S- +Ca2+ + 2 H2O
(undissociated, odorous)
(ion, no odor)
(CH3)3N+
(ion, no odor)
odorous)

(CH3)3N
(undissociated,
Methanethiol and Trimethylamine are highly soluble
in sludge even in undissociated form
TMA Partition coefficient sludge/gas 200…600
Dilution with water is reducing odor
Conclusions
•Incubation of sludge in closed bottles produces
headspace gas in dynamic equilibrium.
•PET beverage bottles are useful, economical and safe
for incubation of sludge odor.
•Cryotrapping GC-MS analysis of headspace is
sensitive, selective and universal for bottle headspace.
•Sludge Headspace odor analysis was used for mass
scale incubation of sludge under various conditions to
explore odor mechanisms.
•All investigated TMA-based Cationic polymer
flocculants can produce TMA odor by polymer
breakdown.
•Sludge liming is unlikely to produce trimethylamine
(TMA) but it is transforming TMA into a volatile form
which causes odor.
•Liming reduces the odor of the most odorous sulfur
compound methanethiol by the pH-effect and by
dimerisation to form less odorous DMDS.
•Numerous technical parameter can influence odor in
addition to polymer flocculant effects.