Investigation of the aerobic and anaerobic
biodegradability of sulfonamides
Evgenia Logunova, Annette Haiß, Klaus Kümmerer
Institute of Sustainable and Environmental Chemistry, Leuphana University Lüneburg
Substances
Introduction
Investigetion of 11 selected Sulfonamides:
Sulfadiazine, Sulfathiazole, Sulfamerazine, Sulfadimine/ Sulfamethazine,
Sulfamethoxypyridazine,
Sulfamethoxazole,
Sulfadimethoxine,
Sulfaguanidine
monohydrate,
Sulfachloropyridazine,
Sulfapyridine,
Sulfanilamide
and structurally similar substances
Sulfonamides are antibiotics frequently used in veterinary medicine. After application the
sulfonamides and/or their metabolites can reach the environment via animal manure used
directly as fertilizer in the agriculture or as fermentation residues after generating renewable
energy by biogas plants. The objective of the project is to reduce the input of sulfonamides in the
environment.
Material and Methods
Aerobic Biodegradability
Anaerobic Biodegradability
The aerobic biodegradability was tested
with two tests: the Closed Bottle Test
(CBT, OECD 301D) and the Manometric
Respiratory Test (MRT, OECD 301F)
For 11 selected sulfonamides additionally
the primary elimination was monitored by
HPLC-analysis.
The anaerobic biodegradability was
investigated with digested sludge from
a municipal sewage treatment plant
(STP). Furthermore an anaerobic test
system was established to investigate
anaerobic biodegradability with manure
from a biogas plant.
CBT-measurement
CBT
“ready”
5
MRT
“ready”
30
Bacterial
density
Testing
time
Simulated
environmental
compartment
28 d
surface water
28 d
surface water
increase
Test
OECD
biodegradability
ThOD of
compounds
[mg/L]
Vessels from the MRT
Test
Anaerobic
biogradability
Conc. of
compounds
[mg/L DOC]
Vessels from the anaerobic
biodegradation
Inokulum
Testing
time
Treatment
simutation type
50
digested sludge
28 d
digestion tank
50
manure from a
biogasplant
56 d
biogas plant
Results
Example: Sulfadiazine
Anaerobic Biodegradability
Degradation according to oxygen consumption
Primary elimination measured by HPLC
100
7
6
60
40
20
Degradation:
5
Absolute pressure with digested sludge
4
250
3
2
1
Toxizitätskontrolle (gemessener Wert)
Toxizitätskontrolle (berechneter Wert)
Day 28 tox B
Qualitätskontrolle
8 10 12 14 16 18 20 22 24 26 28
Time [d]
Day 28 B
6
Day 28 A
4
Day 28 tox A
Substanz
2
Day 0
0
Day 0 tox
0
0
Quality control 106%
Sulfadiazine (10-20)%
Toxicity control 97%
200
Pressure [mbar]
Concentation in mg/L
Degradation [%]
CBT
80
150
100
50
0
0
5
10
15
20
25
30
35
-50
Time [d]
SDZ I [mbar]
Degradation according to oxygen consumption
SDZ III [mbar]
Absolute pressure with manure
from a biogas plant
Primary elimination measured by HPLC
100
SDZ II [mbar]
25
150
4
6
8 10 12 14 16 18 20 22 24 26 28
-20
Substanz
Time [d]
Qualitätskontrolle
Toxkontrolle gemessen
Toxkontrolle berechnet
Pressure [mbar]
0
Day 28 tox
2
50
0
0
Day 28
steril
0
5
Day 28 B
0
10
Day 28 A
20
15
Day 0 tox
40
Quality control 55%
Sulfadiazine (-2)%
Toxicity control 50%
100
Day 0
steril
60
Degradation:
20
Day 0
Concentration in mg/L
Degradation [%]
MRT
80
SDZ- Tox [mbar]
Summary
 In the CBT 70 substances were tested while in the MRT 63 compounds were investigated
 According to the results none of the 11 selected sulfonamides can be classified as ready biodegradable in the
aerobic tests.
 Also the HPLC-analysis showed no primary elimination for the 11 selected sulfonamides.
 From the structurally similar chemical compounds only sodium cyclamate was ready biodegradable (>85%).
 In the anaerobic test system with STP sludge none of the 10 tested sulfonamides were biodegradable
 However, 5 sulfonamides showed toxic effects against the anaerobic microorganisms from STP (degradation of
the reference substance < 60%)
 Till now the anaerobic biodegradability of 5 sulfonamides has been investigated with manure from the biogas
plant without showing any anaerobic biodegradation or toxic effects to the biogas substrate. .
 Further 6 sulfonamides will be tested with biogas substrate in the near future.
10
20
30
40
50
60
-50
Time [d]
SDZ II mbar
SDZ-Tox mbar
Conclusions
Knowledge gained from this study as well as from the
other project partners (e.g. fate of these antibiotics in
soils or toxicity of their photo-oxidation products)
could be used in future in QSAR studies for design of
an environmentally friendly sulfonamide (benign by
design).