1. J . Chem. Tech. BiotechnoL 1996,65,265-271
Clinoptilolitesof Western Anatolia as Detergent
Builders
Mujgan Culfaz,*Nurdan Saraqoglu & Ozlem Ozdilek
Department of Chemical Engineering Gazi University, Ankara, Turkey
(Received 29 June 1995; revised version received 30 August 1995;accepted 20 September 1995)
Abstract: The use of clinoptilolites of Western Anatolia in detergents as phos-
phate substitutes was investigated. The cations present in the clinoptilolite
samples were first exchanged with sodium ions. The washing characteristics of
detergent mixtures containing surfactants, clinoptilolite, sodium carbonate and
sodium sulphate were analysed. The stains of coffee, tea and tomato paste were
tested. The washing tests were repeated for different surfactants, i.e. linear alkyl
benzene sulphonate, sodium alkyl sulphate and alcohol ethoxylate and for differ-
ent co-builders, i.e. sodium carbonate and EDTA. In addition, the effects of
detergent dose and detergent formulation on washing were investigated. Other
factors affecting the degree of soil removal such as shaking time, temperature and
water hardness were also studied. The contribution of clinoptilolite to the wash-
ability was compared with zeolite A, zeolite X and sodium tripolyphosphate.
Increasing the shaking time and temperature improves the degree of cleaning.
LAS was the most effective surfactant for use with clinoptilolite. The washing
performance of the detergent mixtures used in the present work was found to be
comparable with that of commercial detergents at low washing temperatures.
Key words: clinoptilolite, detergent builders, phosphate substitutes.
INTRODUCTION
Detergent formulations contain water softening chemi-
cals in order to promote the cleaning action of the
surface active agents. Phosphate compounds are the
most common of these water softeners. Use of
phosphate-containing detergents results in the presence
of phosphorus in sewage. The phosphorus, following
treatment of the sewage and discharge of effluent, con-
tributes to phosphorus levels in stagnant and slowly
flowing surface waters and can contribute to the eutrop-
hication process. Eutrophication can upset the ecologi-
cal balance of natural water sources and lakes by
decreasing the oxygen content of the water. Additives
are being developed as replacements for phosphates in
detergent formulations in order to alleviate the water
pollution caused by detergent-based phosphates.
Because of its advantageous properties of application
and its ecotoxicological safety, the use of zeolite A as a
phosphate substitute has won increasing recognition
since 1976.'-4 Comparison of the characteristics of
* To whom correspondence should be addressed.
sodium tripolyphosphate (STPP) and zeolite A shows
that they possess many identical properties so that the
zeolite can be used partially of wholly to eliminate the
phosphate content in In regard to the
exchange behaviour of zeolite A, there is much liter-
ature indicating that zeolites have sufficient ability as
detergent builders from the standpoint of exchange rate
and capacity for calcium The improvement in
detergent formulations brought about by the use of
zeolite A finally led to the production of non-phosphate
powder detergents, which were first brought onto the
European market in 1983. The legislative and environ-
mental pressures in favour of zeolite continue not only
in Europe and the United States' but also in Japan.13
This new product category was made possible by the
use of special co-builders which ideally complemented
the builder properties of zeolite A. Zeolite A has also
been tested as a builder in liquid detergent^.'^ Several
natural zeolites have also been tested in detergent for-
m u l a t i o n ~ . ~ ~
Natural zeolites with a low cost are really attractive
as phosphate substitutes if they are modified properly
for this purpose. Naturally occurring zeolites contain
265
J . Chem. Tech. Biotechnol. 0268-2575/96/$09.0001996 SCI. Printed in Great Britain

2. 266 M . Culfaz, N . SaraCoGlu, 0.Ozdilek
TABLE 1
Typical Washing Conditions in Japan, USA, Europe and Turkey
Country:
Type of washing machine:
Japan“
Top loading
with a pulsator
USA”
Top loading
with a pulsator
Volume of washing water (dm3)
Washing load (kg)
Recommended detergent dose, (g dm-3)
Water hardness (calcium carbonate, ppm)
Washing temperature (“C)
Washing time (min)
30-45
1-1.5
1.3
50
10-25
5-1 5
50-80
3-4
1.5
100
30-50
10-15
Europe” Turkey
a tumbler a tumbler
20-25 20-25
3-4 3-4
8-10 8-10
250 300
60-90 30-60
Front loading with Front loading with
30-40 20-30
significant amounts of divalent ions such as calcium and
magnesium which must be exchanged with sodium ions.
There are rich reserves of clinoptilolite-type zeolites in
Western Anatolia.I6 The aim of this study is to investi-
gate the potential use of clinoptilolites of Western
Anatolia as phosphate replacements in detergent formu-
lations.
EXPERIMENTAL
Before starting the experiments, the conditions used in
the washing process in Turkey were determined. The
results obtained are shown in Table 1. The washing
conditions are very similar to those in Europe.
The clinoptilolite-type natural zeolite used in the
present work was taken from Bigadic in Western Ana-
tolia. The characterization of clinoptilolite samples are
given in the literature.” The chemical analysis of the
clinoptilolite used in this work is shown in Table 2.
Preparation of clinoptilolitesamples
The clinoptilolite samples as received contain calcium
and magnesium ions. Since these cations must to be
removed from the wash water, the cations present in the
clinoptilolite were exchanged with sodium ions. For this
purpose, the zeolite samples were treated with 2 N
sodium chloride solution at 70°C for about 3 weeks.
TABLE 2
Chemical Composition of Clinoptilolite Samples‘
Weight (%) Number of atoms
in unit cell
SiO,
A1203
MgO
CaO
MnO
TiO,
Na,O
K2O
HZO
67.60
11.30
1.18
3.26
0.77
0.02
0.07
0.30
2.17
13.40
Si
A1
Ca
Fe
Mg
Mg
Na
K
HZO
29.86
5.88
0.78
1.52
0.26
0.78
0.26
1.22
19.70
During this period, the sodium chloride solution was
replaced with fresh 2 N sodium chloride solution. After
this treatment, the zeolite samples were filtered, washed
with distilled and dried at about 75°C in an oven.
Experimental method
For the investigation into the potential use of
clinoptilolite-type zeolites of Western Anatolia in deter-
gents as phosphate substitutes, the parameters of the
experiments were temperature, detergent composition
(amounts of zeolite, surface active agent, sodium car-
bonate and sodium sulphate in detergent), detergent
dose, the type of surface active agent, the hardness of
the wash water, washing time and the type of soil.
The steps followed during the washing experiments
are :
(i) The wash water was prepared at selected hard-
nesses (310ppm, 200ppm, 100ppm and Ca2+/
Mg2+= 0.78). These are the typical values obtained
from the wash water used in Turkey.
(ii) The detergents with specified compositions were
prepared. The test detergents contained surface active
agent, and primary and secondary building materials.
(iii) Soil solutions of coffee, tea and tomato paste
were prepared. For this purpose a certain amount of
soil was dissolved in 100 cm3water.
(iv) White cotton textile materials (5 cm x 10 cm)
were soiled with the solutions prepared in step (iii).For
this purpose, the soil solution was poured onto a flat
surface and the textile was wetted with this solution.
This operation was repeated three times in order to
obtain a homogeneously soiled textile. Finally, these
textiles were dried.
(v) Water with a known hardness, the detergent, and
the textile were put in a glass container. This container
was then placed in shaking water bath (95 rev min-’)
and the washing process was carried out at the selected
temperature and washing time.
(vi) The washed textiles were taken out and rinsed
with about 200 cm3 water in a shaking bath. This oper-
ation was repeated three times.
(vii) The textiles were then dried and ironed.

3. Clinoptilolites as detergent builders 267
(viii) The whiteness of the textiles as measured in a
(ix) The same washing operation was repeated for the
(x) Finally, the percent soil removal was calculated
Carl Zeiss Reflectometer.
clean textile.
from the following relationship:
Percent soil removal = ~R, - Rsx 100
Ro - Rs
R,: reflectance of the soiled textile after washing
R, : reflectance of the soiled textile before washing
R,: reflectance of the clean textile after washing
Experimentalparameters
For testing the non-phosphated detergent containing
clinoptilolite, a series of washing experiments as carried
out at different parameter values. The following sections
summarize the parameters of the experiment.
Type of soil
In the experiments, three different soils were tested.
These were coffee, tea and tomato paste. But for the
analysis of the other parameters, coffee was mainly used
as the source of soil.
Temperature
The washing experiments were carried out at 1O"C,
30°C and 60°C, representing cold, warm and hot water
respectively.
Wash time
In general, increasing the wash time would improve the
cleaning. But, most of the cleaning operation would be
completed at the early stages of washing. In the present
work, the washing experiments were repeated at three
different contact times, i.e. 2 min, 5 min and 15 min.
Water hardness
The calcium and magnesium ions present in the water
make the removal of soil from textiles difficult. The
building materials present in the detergent keep these
ions away from the washing medium by complex forma-
tion or ion exchange mechanisms. Therefore, hardness
of the original water is also important in testing the
cleaning action of a detergent. The hardness of the orig-
inal water was set at values of 100 ppm, 200 ppm and
310 ppm (in terms of the CaCO, hardness). These are
the representative values for wash water.
Detergent composition and dose
As shown in Table 1, the normal detergent dose used in
Turkey is 8-10 g drn-,. The ion exchange capacity of
clinoptilolite is however one-fifth that of zeolite A. This
will clearly increase the necessary detergent dose. For
the present work, the normal detergent dose was taken
as 20 g dm-3 which is two times the normal dose. The
components were 3.2 g dm-, surface active agent,
10 g dm-3 clinoptilolite, 4.1 g dm-, sodium carbonate,
and 2.7 g dm-, sodium sulphate. In some experiments,
the dose was halved in order to see the effect of deter-
gent dose on soil removal. The amount of each com-
ponent was also changed systematically.
Type of surface active agent
The cleaning action of a surface active agent may be
affected by the type of builder material. For this
purpose, the following surface active agents were used
together with clinoptilolite:
Linear alkyl benzene sulphonate (LAS):
A""'
YS0,Na
Sodium alkyl sulphate (AS):
C,2H2,-S0,Na
Alcohol ethoxylate (AE):
C,,H,,-O{CH,-CH,-O},H; n = 7-10
Linear alkyl benzene sulphonate and sodium alkyl
sulphate are anionic surfactants whereas alcohol
ethoxylate is non-ionic.
Comparison of the detergent builders
Sodium tripolyphosphate and zeolite A are used com-
mercially as the detergent builders. Zeolite X is also a
potential builder because of its selectivity to magne-
sium. For comparison, as set of experiments was per-
formed by substituting clinoptilolite with STPP, zeolite
A and zeolite X. Different doses of these builders were
also tested. In most of the experiments, sodium carbon-
ate was used as a co-builder. In some experiments, dif-
ferent amounts of EDTA were added as a secondary
co-builder.
For the determination of the effects of the above-
mentioned parameters, the suitable operating condi-
tions and the detergent compositions that can be
suggested for clinoptilolite, a total of 186 washing
experiments were carried out.
RESULTS AND DISCUSSION
In the experiments, four different detergent composi-
tions were mainly used. These are given in Table 3.
Detergent I and detergent I1 have the same composi-
tion, but the dose is halved. Detergents I11 and IV
contain different surface active agents, namely alkyl
benzene sulphonate and alcohol ethoxylate, respec-
tively.
The effect of temperature on cleaning for different
soils is shown in Fig. 1 which also shows, the effect of
detergent dose. Increasing the temperature and deter-
gent dose increases the percent soil removal for coffee
stain and tomato paste. But the percent soil removal
was very low for tea and it showed a very small increase

4. 268
60
A
$ 50
0
I
W
a 4 0 -
-I
0
v)
zW
-
b 30
TABLE 3
Detergent Compositions
-
-
-
M . Culfaz, N . Saracogjlu, 0.Ozdilek
V
w
a
a. 20
10
Components (mg per 100 cm3) Detergent I Detergent I I Detergent III Detergent 1V
'
- -LAS 320 160
320AS
- 320AE
Clinoptilolite 1000 500 1000 1000
Sodium carbonate 270 135 210 210
Sodium sulphate 410 205 410 410
__- -
- -
A
E
30-
w
with temperature and no appreciable change with deter-
gent dose.
Figure 2 shows the effect of the hardness of the wash
water. As expected, increasing water hardness decreases
the cleaning effect of the detergent. At low water hard-
nesses (100 ppm), the effect of detergent dose and soil
type was much more pronounced. At higher values of
water hardness (310 ppm), the variation observed in
percent soil removal becomes less. Figure 3 shows the
effect of water hardness on percent soil removal using
three different surface active agents, i.e. it shows the
results of the experiments with detergents I, 11 and IV.
From this figure, it is clearly seen that LAS is the most
suitable surface active agent for use with clinoptilolite.
The performances of alkyl benzene sulphonate and
alcohol ethoxylate are very similar. The same result was
obtained for the case where zeolite A was used as the
detergent b~i1der.I~
The amount of clinoptilolite to be used in the deter-
gent mixture was selected as 1000 mg per 100 cm3.This
was the amount of clinoptilolite equivalent to the
zeolite A which is used commercially in the sam deter-
gent mixture and dose. When the theoretical ion
__----_----r
1
l o I
Detergent Stoin--
o I Coffee
II coffee
A I TCO
A I Teo
0 I Tomato
m II Tomoto
"0 10 20 30 40 50 60
TEMPERATURE, *C
Fig. 1. Effect of temperature on soil removal (washing time:
15 min; water hardness: 310 ppm CaCO,).
Deterpent Stoin--
I Coffee0
0 2 Coffee
A I Tea
A 2 TeO
0 1 Tomato
2 Tomoto
0' I I I
0 100 200 300
WATER HARDNESS, ppm CoCOJ
Fig. 2. Effect of hardness and detergent dose on soil removal
(temperature: 30°C;washing time: 15 min).
60
A
3 50
0
I
W
a 40
J
0
In
z
W
V
K
-
c 30
2 20
10
Detergent Stoin--
0 I Coffee
o m Coffee
o Bl Coffee
0' 1 I I
0 100 200 300
WATER HARDNESS, ppm CoCOs
Fig. 3. Effect of type of surfactant on soil removal
(temperature: 30°C; washing time: 15 min).

5. Clinoptilolites as detergent builders 269
exchange capacities of clinoptilolite and zeolite A were
compared, it was found that 1 g clinoptilolite is equiva-
lent to 0.18 g zeolite A. The use of clinoptilolites as an
alternative builder material makes it necessary to opti-
mize the suitable detergent components and their dose.
For this purpose, a set of experiments was carried out
with detergent I by changing the amount of each com-
ponent systematically. The results are shown in Fig. 4.
The increase in the amounts of LAS and sodium car-
bonate caused an increase in percent soil removal. In-
creasing the amount of clinoptilolite within the range of
500-2000 mg per 100 cm3increased the percent soil re-
moval very little. The same is true for sodium sulphate.
The washing time was varied from 2 min to 15 min.
These experiments were carried out with detergent I
and detergent 11. The results are given in Fig. 5.At low
detergent doses, the degree of soil removal increased
60
steadily with increasing wash time, however, this
increase was very small. This means that the effect of
washing time is not very important at low detergent
dose. On the other hand, with detergent I, changing the
washing time from 2 min to 5 min caused a sharp
increase in soil removal and then a very small change
was observed from 5 min to 15 min.
As mentioned above, clinoptilolite was used as a
builder material in most of the experiments. For com-
parison, some of the experiments were carried out with
other builder materials (zeolite A, zeolite X, STPP and
EDTA) and mixtures of these. The results of these
experiments at 10°C and 60°C are given in Fig. 6.The
compositions of the detergents (except the commercial
detergent) are given in Table 4.From Fig. 6,it can be
clearly seen that the performances of STPP and clinop-
tilolite are very similar to each other. Addition of
50
c
e
E 20
Q
10
0
U S Clinoptilolite Sodium carbonate Sodium sulphate
Fig. 4. Effect of change in the amounts of LAS, clinoptilolite, sodium carbonate and sodium sulphate on soil removal for detergent
I. (temperature: 10°C;washing time: 15 min; water hardness: 310 ppm CaCO,).
TABLE 4
Composition of the Detergents Given in Fig. 6
Detergent mixture Composition (mg)
A B C D E F G
__
1000
-
320
-
410
270
-
410
270
-
1000
320
-
-
410
270
1000
-
-
320
-
410
270
500
-
-
160
-
205
135
1000
-
-
320
410
270
-
1000
-
-
320
420
270
Clinoptilolite
STPP
Zeolite A
Zeolite X
LAS
AS
AE
Sodium sulphate
Sodium carbonate
H: Commercial detergent.

6. 270
60
5 0 -
0
a!
4 0 -
-I
2
g 30
a
w
V
:2 0 -
10
-
-
-
Oetergenl Stain
0 1 Coffee
0 2 Coffee
A I Tea
A 2 Teo
0 1 Tomolo
m 2 Tometo
--
I 1 I
5 10 15
01
0
WASHING TIME, min
Fig. 5. Effect of washing time on soil removal (temperature:
60°C; water hardness: 310 ppm CaCO,).
EDTA as a secondary co-builder improves the per-
formance of the detergent. At low temperature, the per-
formance of zeolite A is slightly better than that of
clinoptilolite. This difference becomes less at high tem-
perature. Another conclusion is that the performances
of detergents, including the commercial detergent used
in automatic washing machines, were similar at 10°C.
Commercial detergent, however, gives higher values of
percent soil removal (about 85%) at 60°C. Commercial
detergent, however, contains some bleaching agents and
enzymes whereas the others do not.
Finally, a suitable composition for a clinoptilolite-
based detergent is 16% LAS, 50% clinoptilolite, 13.5%
sodium carbonate, and 20.5% sodium sulphate. With
this detergent composition, at 310 ppm water hardness,
60°C and 15 min wash time, the percent soil removal
obtained was 60.6% for coffee, 57.5% for tomato paste,
42 70 i
A B
IC
010 degreec
D E F G H
Fig. 6. Comparison of washing effects of different detergent
mixtures (washing time: 15 min; water hardness: 310 ppm
CaCO,).
and 44.2% for tea. This detergent composition was
compared with nine different commercial detergents at
detergent doses of 10 g dm-3 and 20 g dm-3 and at
temperatures of 10°C, 30°C and 60°C. The results are
given in Table 5.
CONCLUSIONS
The results of the washing experiments with
clinoptilolite-based detergent mixtures can be sum-
marized as follows:
(i) Higher temperatures and longer washing times
improve the cleaning action of the detergent.
(ii) Among the surface active agents used in the
present work (LAS, AE and AS) LAS seems to be the
most suitable for use with clinoptilolite.
(iii) Addition of EDTA as a co-builder improves the
performance of clinoptilolite. For several reasons
TABLE 5
Percent Soil Removal for Different Detergent Formulations(washing time: 15 min, water hardness: 310 ppm)
Detergent type Detergent dose: 10 g dm-, Detergent dose: 20 g dm-,
10°C 30°C 60°C lO0C 30°C 60°C
Commercial detergent 1
Commercial detergent 2
Commercial detergent 3
Commercial detergent 4
Commercial detergent 5
Commercial detergent 6
Commercial detergent 7
Commercial detergent 8
Commercial detergent 9
Average of nine commercial detergents
Present work (detergent 11)
44
48
40
47
54
51
45
43
46
46
43
49
57
45
43
51
59
67
58
62
56
45
60
62
64
61
63
67
75
64
71
65
60
46
53
41
48
56
51
48
53
53
50
49
63
64
66
62
73
71
70
60
71
67
52
75
83
73
80
85
85
19
68
85
79
61

7. Clinoptilolites as detergent builders 271
including cost, EDTA is used at low levels (0.18%-
0.5%) in fabric washing products."
(iv) At low temperatures, zeolite A and zeolite X are
more effective in cleaning than STPP and clinoptilolite.
The effectiveness of all these builders are nearly the
same at high temperatures.
(v) In most of the experiments, detergent I(16% LAS,
50% clinoptilolite, 13.5% sodium carbonate, and 20.5%
sodium sulphate) was used and its performance is very
close to that of a commercial detergent formulation at
low temperature. The detergent mixture that was used
in this study can further be improved by adding blea-
ching agents and enzymes. This detergent should also
be tested with other types of soils and textiles.
(vi) The use of clinoptilolite as a builder would
increase the detergent dose.
ACKNOWLEDGEMENT
The financial support provided by The Scientific and
Technical Research Council of Turkey (TUBITAK,
KTCAG-75) is gratefully acknowledged.
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