C h e m o s p h e r e , Vol.19, Nos.lO/ll, P r i n t e d in G r e a t B r i t a i n
LIPOPHILIC
pp 1623-1627,
AND E L E C T R O P H I L I C
OF S U B S T I T U T E D
PHENOLS
P.Beltrame*, Dipartimento
di C h i m i c a
1989
FACTORS
IN THE I N H I B I T I N G
ON THE B I O D E G R A D A T I O N
P.L.Beltrame,
Fisica
Via Golgi
0 0 4 5 - 6 5 3 5 / 8 9 $3.00 + .00 P e r g a m o n Press ple
20133
OF P H E N O L
and P . C a r n i t i
ed E l e t t r o c h i m i c a ,
19,
ACTION
Milano,
Universita
di Milano,
Italy
ABSTRACT
Monosubstituted were
used
kinetic latter
as
phenols
inhibitors
measurements, quantity
inhibitors. previous
was
The
the
QSAR
inhibition
showing
or
para
phenol
action
with to
based
different
that
the
can be the p h e n o l ' s
was
structural
referring on
substituents:
degradation
inhibiting
correlated
correlations
inhibitors,
(meta
of the
the
expressed
as
properties
present
CI,
predominant
PI50,
is
and
CN,
NO 2)
sludge.
(logP,
system
sludges
largely
MeO,
by an a c t i v a t e d
and
the
of
the
o)
compared
different factor
By
with
sets
of
of
phenolic
lipophilicity.
INTRODUCTION
Substituted show
an
(1-3). the
Such
constants and
weight
activated
action
of
C1
correlated
with
lipophilicity substituents,
factors
and/or
NO 2) were
biodegradation
factors was
found
by
structural
(logP)
of
so a s s e s s i n g in
the
to
vary
reported
activated
properties
the
molecules
the
importance
inhibiting with
the
to
sludges
power.
nature
of and of The
of
the
kinds
of
sludge. all
these
substituents,
i.e.
C1
set
carrying
was the
(o) of the
these
being
phenol
electrophilic
However,
larger
on
particularly
lipophilic
relative
(substituents
action
inhibiting
inhibitors,
the ~ a m m e t t the
phenols
inhibiting
and
of substituents,
one
inhibitors
findings
of
of
these
phenol
NO 2.
We
were
obtained
felt
convenient
including
substituents degradation.
MeO
will
1623
to
only
extend
and CN besides
in meta They
using
or be
in p a r a
C1
the
as
study
to
a
and NO 2. Phenols
to OH
indicated
two
were 3-MOP
tested and
as
4-MOP
1624
(m e t h o x y p h e n o l s ) ,
3-CP
and
(hydroxybenzonitriles), phenols
were
MATERIALS
not used
AND
Activated as
zero),
then
were
sole
by
a sludge
no.2
and
in
the
(i)
Pseudomonas bacteria sludge these
(2),
as
4-CNP
revealed
(2).
the
counting
(2).
phenol
was
An
no.2,
the
di
Microbiologia
Medica,
were
as a very
small
fraction
of the
: 20
Pseudomonas
: 100,
and
indicating
no.3
and no.3
Nocardia
Nocardia,
i00
Although
no.2
no.2
of
around
and Nocardia,
for in sludges
Istituto
was
product
Pseudomonas
to
obtained
procedure).
sludge
2.3
stock
been
concentration
of the g e n e r a
by
had
to
close
uniform
no.l
sludge
looked
conditioned
concentration
sludge
for
were
made
in
a
as
Bacteria
only
in ratios
of
plant
phenol
( a
grade.
(2) by the present
procedure
no.l,
a
described
no.3
presence
While
treatment
(with
sludge
(analysis
present
were
carbon
the
same
Milano).
were
no.3
and
Ortho-substituted
previously
of a n a l y t i c a l
wastewater
in sludge
reconditioning di
products
stored,
composition.
found
Universita
3-CNP
(nitrophenols).
"ortho-effect"
had been p r e p a r e d
following
previously
a of
activated
conditioning
hgd a d i f f e r e n t
not
detected
total
total
a large
and
count
of
bacteria
in
population
of
bacteria. Kinetic
(2),
from
collected
(1,3)
obtained
4-NP
the
commercial
source
labelled
mg/L;
a ft e r
to a v o i d
sludge
the
collected,
(chlorophenols),
and
METHODS
All p h e n o l s
phenol
4-CP
3-NP
at
measurements
20.010.1°C,
of the phenol value,
when
of
using
removal
phenol
portions
of
rate w i t h o u t
compared
with
biodegradation activated
inhibitor
the typical
value
were
sludge
(U o) were (2)
for
done
no.3. around
sludge
as
described
Typical 0.06 no.2
values
h -I. (U
This = 0.02
O
h-l),
shows
that a c t i v a t e d
a fact p r e s u m a b l y As
done
inhibitor calculate removal ICs0
on
and
related
U
with
similar
a
kinetic
concentration
(concentration
Values
of
PIs0
more
active
than
no.2,
composition.
occasions,
known
of ICs0
= Uo/2).
no.3 was n o t i c e a b l y
to its b i o l o g i c a l
previous U
the value
rate
sludge
of
results it)
of inhibitor
were
calculated
(U °
were
able as
with
no
employed
to
to give a phenol log(i/ICs0),
with
in mmol/L. For the
of the
subsequent
inhibitors,
MeO and CN groups,
RESULTS
AND
The
each
larger
for
values.
In
using
of the results
of logP were m e a s u r e d a recently
described
with
structural
for phenols
procedure
properties
substituted
with
(2).
DISCUSSION
results
within
correlation
values
obtained
couple the
meta
general,
of
are
presented
meta/para
than
for
along
the
Table
in Table
phenols para I,
with
isomer, the
the as
roughly
I.
It can
same it
be
noticed
substituent, is
true
increasing
also
order
that,
PI50
is
of
logP
of
PIs0
1625
values
corresponds
order
of
a
quantitative
logP,
correlated
0,
and
with
disregarding
R,
to
the
I.
correlation,
R
logP
(molar
order
of
following
logP:
logP
Inhibiting
action a
substituted
phenols.
structural
values
than
and
IC50
parameters
However,
correlation
correlation
= a 1 + a2"logP
Compound
the
r e f r a ct i v i t y ) .
(for R vs.
the
PI50
TABLE
closely
to
the
a-values.
For
were
more
R
is
coefficient
considered
significantly r = 0.60).
So,
was used:
(1)
+ a3.a
structural
properties
PI50
logP
of
variously
ab
mmol/L
4-MOP
0.711
0.148
1 37
-0.268
3-MOP
0.652
0.186
1 62
0.115
4-CNP
0.565
0.248
1 56
0.660
3-CNP
0.484
0.315
1 70
0.560
4-NP
0.584
0.234
1 93 c
0.778 0.710
3-NP
0.389
0.410
2 05 c
4-CP
0.175
0.757
2.43 d
0.227
1.208
2.55 d
0.373
3-CP
a on the b refer.4 c d
biodegradation
refer.
3
refer.
2
TA B L E
0.062
2.
Results
of
phenol
of r e g r e s s i o n
(where Zo r e p l a c e s
analysis.
sludge
Comparison
no.3
with
previous
cases
a in eq.(1)).
sludge
substituents
points
MeO,CN,NO2,Cla'b
8
-1.05
0.83
-0.20
0.92
I0
-1.15
0.66
-0.16
0.99
3
-0.66
0.20
0.81
0.87
1,3
2
NO 2 a n d / o r
1
NO 2 o r
a mono-substitution b never
ortho
to OH
Cl b
C1 b
only
8
aI
a2
a3
Refer.
Types
3
No.of
r
Activated no.
of
by activated
this work
1626
Multiple the
results
pr e v i o u s
are
quick
sludge
no.3
obtained for
sludge
no.l
was
phenol no.3
look
at
Nocardia
The
on
of
the to
and
similar weight
(logP)
inhibitors relative
given
in Table It
set
is
As
more
sets
a matter in
mg/L,
while
both
they
have
lipophilic
of
of
procedure
fact,
sludge
presence
of
a
sludges
no.2
and
zero.
Now,
for
to
in p o p u l a t i o n
employed
electrophilic
form
with
to those
with
of
different
a I, a 2, and a 3 were
and
in the e q u i v a l e n t
close
been
the
the
differences
of p a r a m e t e r s
results than
on
grown
large
the no.2
been
found.
factors
can
be
(2):
o + a~
(2) °av
: la~i/Cia~l+Ja~i)
that
different
runs with
sludges
TABLE
Relative
3.
some
and
fel
:
variables
for the
a~ = a3.Oav.
Ja~J/Cla~i+Ja~J)
The are
3.
apparent
largely
that
and o are average values of the respective av av taken into c o n s i d e r a t i o n; a~ = a2-(logP)av; flip
obtaining also
different
sludge
depend
factors.
show
although
the
with
results
100
= a I + a~
weights
(i),
comparison, and
appreciate
(logP)av where
of
sludges
logP PIso
described
sake
concentration
they
values
of
eq.(1)
of
phenol
although
to
having
order
a
as
For
obtained
other
conditioned,
Pseudomonas
by w r i t i n g
enough
Therefore,
and no.3,
relative
assessed
is
than
2.
activated
no.l.
conditioned
and
2
applied,
2.
to those
sludge
of inhibitors,
was Table
different
conditioning
no.2
of
in Table
Table
concentration
sludges
row
similar
differently
were
sets
with
reported
are more
with
analysis
first
results,
compounds, A
regression in the
no.2
sludges
the other
set,
activated in w h i c h
no.l
the
of
lipophilic
inhibiting
and
action
electrophilic
of
a
phenols
a
flip
fel
Refer.
no.
3
0.96
0.04
0.94
0.06
3
1
0.43
0.57
3
with
no s u b s t i t u e n t
ortho
to OH
this
work
a
together
factors
substituted
2
a for i n h i b i t o r s
represent
can c o n s i d e r
no.l-3.
Activated sludge
sludge one
and no.3.
weights
affecting
experiments with
from
in on
1627
Therefore, when using an activated sludge as usually found in a plant at steady
state,
predominant
i.e.
effect
conditioned of
phenolic
to
a
low
substrate
inhibitors
is
concentration,
correlated
with
the their
lipophilicity.
REFERENCES
I.
P.Beltrame, P.L.Beltrame, and P.Carniti, Chemosphere,
2.
P.Beltrame,
P.L.Beltrame,
Biotechn. and Bioen~., 3.
P.Carniti,
D.Guardione,
13, 3 (1984). and
C.Lanzetta,
31, 821 (1988).
P.Beltrame, P.L.Beltrame, P.Carniti, and C.Lanzetta, Chemosphere,
17, 235
(1988). 4.
C.Hansch and A.Leo,
"Substituent Constants for
Chemistry and Biology", Wiley, New York,
Correlation
1979.
(Received in Germany 3 August 1989; accepted 6 September 1989)
Analysis
in