Combined Methods of Highly Polluted Pharmaceutical Wastewater Treatment - a Case Study of High Recovery

Abstract

Our study details the investigation of real pharmaceutical wastewater (PhWW) treatment. A combination of the Fenton process, sand filtration, ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) was tested. The sample of PhWW was highly polluted, containing high chemical oxygen demand (COD, 25,000 mg•L-1), total organic carbon (TOC, 4,940 mg•L-1), conductivity (κ, 40,000 mg•L-1), and total N (4,054 mg•L-1) values. The pretreatment (Fenton, sand filter, UF) decreased the above parameters for 62%, 56%, 10%, and 88%, respectively. An additional membrane treatment was required since the values obtained in the pretreatment were above maximum contaminant levels (MCLS). The next membrane step with the loose NF membrane (HL) COD, TOC, conductivity, and total N additionally decreased for 87%, 71%, 24%, and 32%, respectively. Tight NF (NF90, NF270) and RO (XLE) membranes were used in the final step and, according to the obtained parameters, membrane permeate streams could be discharged into the sewer without any risk to the ecosystem. Finally, and the most importantly, the combined methods of the pharmaceutical wastewater treatment resulted in high recovery of more than 90%.

Full text

Introduction
The generation of wastewaters in industrial processes is
unavoidable, and in most cases a process of reducing the
organic load and other contaminants must be employed
before water discharge. Domestic sewage is the largest
source of water pollution, followed by industrial effluents
and agricultural activities [1, 2]. Industrial waste, in partic-
ular when it contains harmful chemicals, heavy metals, and
other toxic substances, can have far more serious conse-
quences than domestic waste. These hazardous substances
pollute surface water, soil, and groundwater and become
concentrated in the food chain, and therefore need special
treatment before being discharged.
The wastewater generated by industrial activities
(chemical, cosmetic, pulp and paper, pharmaceutical indus-
tries, etc.) is one of the most complex wastewaters. This
complexity, strongly related with the difficulty in establish-
ing simple and, at the same time, effective treatment and
disposal method for such a wastewater stream, may be
illustrated in terms of many specific characteristics:
(1) a strong organic carbon content often associated with a
chemical oxygen demand (COD) level in excess of
10,000 mg·L
-1
[3-6]
Pol. J. Environ. Stud. Vol. 22, No. 6 (2013), 1677-1683
Original Research
Combined Methods of Highly Polluted
Pharmaceutical Wastewater Treatment –
a Case Study of High Recovery
Davor Dolar
1
*, Krešimir Košutić
1
, Tatjana Ignjatić Zokić
2
,
Laszlo Sipos
2
, Marinko Markić
2
, Mario Župan
2
1
Department of Physical Chemistry,
2
Department of General and Inorganic Chemistry,
Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, HR-10000 Zagreb, Croatia
Received: 8 November 2012
Accepted: 19 August 2013
Abstract
Our study details the investigation of real pharmaceutical wastewater (PhWW) treatment. A combina-
tion of the Fenton process, sand filtration, ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO)
was tested. The sample of PhWW was highly polluted, containing high chemical oxygen demand (COD,
25,000 mg·L
-1
), total organic carbon (TOC, 4,940 mg·L
-1
), conductivity (κ, 40,000 mg·L
-1
), and total N (4,054
mg·L
-1
) values. The pretreatment (Fenton, sand filter, UF) decreased the above parameters for 62%, 56%, 10%,
and 88%, respectively. An additional membrane treatment was required since the values obtained in the pre-
treatment were above maximum contaminant levels (MCL
S
). The next membrane step with the loose NF
membrane (HL) COD, TOC, conductivity, and total N additionally decreased for 87%, 71%, 24%, and 32%,
respectively. Tight NF (NF90, NF270) and RO (XLE) membranes were used in the final step and, according
to the obtained parameters, membrane permeate streams could be discharged into the sewer without any risk
to the ecosystem. Finally, and the most importantly, the combined methods of the pharmaceutical wastewater
treatment resulted in high recovery of more than 90%.
Keywords: highly polluted pharmaceutical wastewater, Fenton process, membrane processes, recovery
*e-mail: dolar@fkit.hr
Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy •

(2) an organic carbon content that inherently involves a
great variety of complex organic pollutants with a total
organic carbon (TOC) level of a few thousands [7, 8].
The treatment of various industrial wastewaters has
always been considered as a challenging issue for scien-
tists [4, 9]. In the recent past, different treatment schemes
such as coagulation [2, 8], ozone and activated carbon [4,
10], ion exchange [11], Fenton [10-12], membrane biore-
actors [6, 13], nanofiltration (NF), and reverse osmosis
(RO) [14-16] have been tested and suggested. However,
results also identified significant drawbacks and indicat-
ed that no single technology could be applied to the
industrial wastewater as a stand-alone treatment option.
Industrial production can also be considered a source of
significant amounts of reusable effluents. Thus, industry
should be encouraged to invest in improved water manage-
ment, more recycling, and more efficient treatments. It is
also important to raise awareness in government and various
industries in the world to invest in wastewater treatment and
recycling in order to preserve the natural water resources.
This experimental study was performed to evaluate the
efficacy of the combination technique for the treatment of
pharmaceutical wastewater (PhWW) effluent obtained
from a local site. Since the majority of the reported litera-
ture deals with simulated effluents, the current investigation
emphasizes the treatment of real industrial wastewater. Due
to the complexity of the highly polluted pharmaceutical
wastewater, various techniques in this work were used for
its treatment. The pretreatment was done by the advanced
oxidation process (Fenton), sand filtration, and ultrafiltra-
tion (UF). After that, effluent was treated by NF and RO.
Materials and Methods
Characterization of Highly Polluted Raw
Pharmaceutical Wastewater
A fresh sample of wastewater was obtained from phar-
maceutical industry and no pretreatment (decantation, fil-
tration, etc.) was done. The major physico-chemical prop-
erties are given in Table 1, column 2, including COD, con-
ductivity (κ), TOC, pH, etc., where COD indicates the con-
centration of all organic compounds that can be fully oxi-
dized using strong oxidizing agents, whereas TOC usually
indicates the amount of all the organics present in the sys-
tem. The PhWW (200 L) was stored in a plastic carboy and
used within 1 h in the treatment experiments.
The wastewater treatment process consisted of several
steps (Fig. 1), the first involving Fenton’s oxidation treat-
ment with sand filtration and UF of the PhWW to reduce
COD and TOC, among others. The second stage consisted
of a loose NF membrane and the third stage involved tight
NF and RO membranes to eliminate the salts contained in
the loose nanofiltration permeate.
Fenton’s Oxidation Experiments
The first step of the treatment was Fenton’s advanced
oxidation experiment (Fig. 1, part A). The advanced oxida-
tion processes (AOP) proved to be highly effective for the
removal of most of the pollutants in wastewaters [17]. Also,
Photo-Fenton reaction is well-known in the literature as an
efficient method for wastewater and soil treatment [18].
Furthermore, the Fenton system Fe
n+
/H
2
O
2
is one of the
most promising oxidative techniques for the abatement of
refractory and/or toxic organic pollutants in water and
wastewater [12, 19]. The high removal efficiencies of this
technique can be explained by the formation of strong
hydroxyl radical (HO˙) and oxidation of Fe
2+
to Fe
3+
. Both
Fe
2+
and Fe
3+
ions are coagulants. Therefore, the Fenton
process can have dual function in the treatment processes,
namely oxidation and coagulation. Moreover, iron is an
abundant, non-toxic element and can be easily removed,
while hydrogen peroxide is easy to handle environmentally.
The parameters affecting the Fenton process include
dosages of FeSO
4
and H
2
O
2
and operating pH. The opti-
mum pH has been found to be around 3 in the majority of
1678 Dolar D., et al.
Table 1. Wastewater analysis during the first two steps of treatment.
PhWW Effluent 1 Effluent 2
Conc. Conc. R(step 1)/% Conc. R(step 2)/%
COD (mg O
2
·L
-1
)
25,000 9,400 62.4 1,238 86.6
Conductivity (μS·cm
-1
) 40,000 35,700 10.7 27,200 23.8
TOC (mg C·L
-1
) 4,940 2.150 56.5 615.2 71.4
pH 6.00 8.24 - 7.60 -
NH
3
(mg N·L
-1
)
170 457 - 370 19.0
Alkalinity (mg·L
-1
CaCO
3
)
1,780 1,460 18.0 683.7 53.1
Cl¯ (mg·L
-1
) 7,300 8,640 - 6,521 24.5
SO
4
2-
(mg·L
-1
)
520.0 340.0 34.6 22.24 93.5
Total N (mg·L
-1
) 4,054 498 87.7 340 31.7
Total P (mg·L
-1
) 6.96 0.53 0.32 39.6
Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy •

cases [11, 20] and hence is recommended as the operating
pH. On the other hand, adjusting the original pH of the used
PhWW (6.0, Table 1) to the optimal range (around 3) would
consume a considerable amount of acid, increasing the treat-
ment cost. Therefore, the parameter choice should be a
tradeoff between reaction efficiency and treatment cost. Due
to economic reasons, a reduction of COD by 50% was cho-
sen as the optimal condition. The optimal concentration of
H
2
O
2
and Fe
2+
was determined by the JAR test. The PhWW
(1 L) was treated with different concentrations of H
2
O
2
(10-
150 g·L
-1
) and Fe
2+
(0.1-110 g·L
-1
) and various combinations
of these concentrations. The optimal dosage of H
2
O
2
and
Fe
2+
was found to be 32 and 0.6 g·L
-1
, respectively.
Fenton’s oxidation of PhWW was carried out in a reac-
tor as follows: firstly, Fe
2+
catalyst was added to PhWW
from a freshly prepared FeSO
4
·7H
2
O stock solution under a
continuous bubbling of air. Thereafter, wastewater was
heated at approximately 60ºC. Then, H
2
O
2
was gradually
added directly to the reaction solution during 40 min. The
reaction was completed by spiking the sample with con-
centrated NaOH solution to increase the pH to 7-8. After
cooling the reaction solution to the ambient temperature,
and prior to treatment with NF and RO membranes, the
samples were filtered by the sand filter with a granulation
of 0.8-1.2 mm and UF in order to remove the formed
Fe(OH)
3
flocs. The sand filtration and UF were used after
the Fenton process, since the sand filter has good potential
for removing ferric precipitates that would otherwise cause
a significant flux decline and membrane fouling [21].
Ultrafiltration is very often used as a pretreatment to NF
and RO processes [22, 23]. It is a powerful tool for the
reduction of fouling potential of NF/RO membranes, which
increases the overall efficiency and is also very suitable,
since the turbidity of the influent can be up to 100 NTU.
The working pressure was 3 bar, while the active surface of
the membrane was 0.20 m
2
.
The ferrous sulfate (FeSO
4
·7H
2
O, p.a.) was purchased
from Sigma-Aldrich (Steinheim, Germany), while the
hydrogen peroxide solution (30%, w/w) and NaOH were all
purchased from Gram-Mol (Zagreb, Croatia).
The subsequent steps in the experiment were the mem-
brane treatment processes (Fig. 1 parts B and C).
Nanofiltration
The following procedure of NF was performed in a
pilot plant. No pH adjustment was made prior to the exper-
imental studies, since the pH values of the investigated
wastewater samples (6.0-8.45) fell within the ranges rec-
ommended by the manufacturers. The pilot plant [24] was
designed for a maximum operating pressure of 20 bar.
Effluent 1 from the pretreatment was used as feed in the
NF experiments on a pilot plant unit (Fig. 1 part B), where
a commercially available loose nanofiltration membrane,
an HL module with molecular weight cut-off (MWCO)
value of 150-300 Da, was employed. The membrane mod-
ule was spiral wound 2540: L-1000 mm and D-64 mm pro-
vided by Desal, Osmonics, GE Infrastructure Water &
Process Tech., Vista, CA. The active surface of the mem-
branes was 2.5 m
2
. The operation conditions during the
experiments were: the pressure feed P
feed
-9.2 bar; the pres-
sure on membrane element P
m
-8 bar, and recirculation of
retentate Q-600 L·h
-1
. The membrane module was stored in
a 1.5% sodium disulfite and before treatment of effluent 1
it was rinsed with pipe water. After the treatment, a mem-
brane module was cleaned with alkali (1.5%-RoClean
Combined Methods of Highly Polluted... 1679
Fig. 1. Scheme of pharmaceutical wastewater treatment.
Wastewater Inlet
Concentrate
NF membrane
(HL)
RO membrane
(XLE)
NF membrane
(NF90)
NF membrane
(NF270)
Permeate
Permeate
Permeate
Fe
2+
FENTON
REACTOR
SAND
FILTER
EFFLUENT 1
EFFLUENT 2
pH Corr.
H
2
O
2
UF
PART A
PART B PART C
Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy •

P211, Avista Technologies (UK) Ltd) and acidic (1.5%-
RoClean P303, Avista Technologies (UK) Ltd) agents for
cleaning, washed with the pipe water and then with the
demineralized water.
The initial volume of the pretreated PhWW was 200 L
and during the operation the retentate stream was recircu-
lated to the feed tank. Therefore, the feed solution was con-
tinuously concentrated (volume reduction factor, VRP).
VRP was defined as:
(1)
...where V
0
represents the processed feed volume, while V
R
and V
P
represent the retentate and permeate volumes (L),
respectively.
The permeate recovery was calculated according to the
following formula:
(2)
The Final Membrane Treatment
The final step was a treatment of effluent 2 with dense
nanofiltration membranes (NF90 and NF270) and reverse
osmosis membranes (XLE). All the membranes were from
Dow/FilmTec, Midland MI, and were used in laboratory
set-up as described in the previous research [25].
The aliquots collected after each step were subsequent-
ly subjected to analytical measurements.
Analytical (Environmental) Parameters
The conductivity, COD, TOC, total N, total P, free
ammonia (NH
3
), phosphate (PO
4
3-
), nitrate (NO
3
¯), nitrite
(NO
2
¯), sulfate (SO
4
2-
), chloride (Cl¯), and pH were moni-
tored. All parameters were measured three times and the
average values are given in all tables. Standard deviations
were under 11%.
Conductivity was determined by conductometer
(SCHOTT Instruments Lab 960, Germany), while concen-
trations of TOC were determined by a Shimadzu TOC-
VWS carbon analyzer (Japan). All other chemical charac-
teristics of the PhWW (mentioned in this section) before
and after treatment were analyzed according to standard
methods for the examination of water and wastewater [26].
All chemicals used throughout the experiment were at least
of analytical grade.
Results and Discussion
Characterization of the Raw Pharmaceutical
Wastewater
The analysis of the PhWW in terms of conventional
environmental parameters is given in Table 1, column 3. As
shown in this table, the organic content of the PhWW was
characterized by a high COD and TOC levels of around
25,000 and 5,000 mg·L
-1
, respectively. These results indi-
cate that the PhWW contained a very high load of organic
matter. The high concentrations of total N (4,054 mg·L
-1
)
and total P (6.96 mg·L
-1
) can have great impact on the envi-
ronment. The most common problem with the effluents dis-
charged in the environment from the municipal or industri-
al plants is eutrophication. This phenomenon is responsible
for the dramatic growth of algae occurring in the internal
and the coastal waters. Also, a significant fraction of total N
and total P may:
(1) accumulate in soils
(2) move from the land into surface waters
(3) migrate into groundwaters
(4) enter the atmosphere via ammonia volatilization and
nitrous oxide production
Also, the PhWW was characterized by very high con-
ductivity, ammonium, and chloride concentrations of
40,000 μS·cm
-1
, 170 mg·L
-1
, and 7,300 mg·L
-1
, respectively.
According to the presented results, the selected PhWW
was highly polluted pharmaceutical wastewater and has to
be treated combining several treatments. The choice in this
work was Fenton process, sand filtration, UF, NF, and RO
in order to meet maximum contaminant levels (MCL
S
) for
the discharged effluent in natural aquifers or sewer systems.
Fenton Process, Sand Filtration,
and Ultrafiltration
Analysis of effluent 1 (PhWW after Fenton process,
sand filtration and UF) is given in Table 1, column 3. The
results show that the above-mentioned processes reduced
COD and TOC for 62% and 56%, respectively. A little
lower decrease of TOC value compared to COD implies
that some of the organic compounds were degraded into
organic byproducts instead of being mineralized to CO
2
and
H
2
O. The conductivity was still high (reduced for 10%),
due to the addition of FeSO
4
during the Fenton process. The
total N and total P were satisfactorily removed, 88% and
95%, respectively. The concentration of total P decreased
below MCL
S
, but the concentrations of total N and other
parameters were above MCL
S
values and required addi-
tional treatment.
Nanofiltration Using the Looser Membranes
Effluent 1 was further treated by nanofiltration on the
pilot plant using an HL membrane spiral wound module.
Column 4 of Table 1 presents results from the beginning
(first hour) of the nanofiltration procedure. The COD and
TOC contents during step 2 were additionally reduced for
86.6 and 71.4%, respectively. According to these results, it
can be concluded that the effluent after NF contains a high
concentration of ions and organic components of low mol-
ecular mass. This could have been expected due to the HL
membrane pore size bigger than 0.71 nm [25] and MWCO
between 150-300 Da. The conductivity was reduced only
for 24%, due to the very high initial conductivity value
100(%)Recovery
0
u
V
V
P
pR
VV
V
V
V
VRP

0
00
1680 Dolar D., et al.
Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy •

(35,000 μS·cm
-1
). Dolar et al. [25] reduced conductivity
with the same membrane for 66%, but with much lower
conductivity in the feed (2,000 μS·cm
-1
). At this stage of
treatment two parameters were below MCL
S
(sulfate and
total P).
The initial volume of the PhWW was 200 L, and after
the treatment there was 15 L of retentate, so VRP and recov-
ery were 13.3 and 92.5%, respectively. A recovery higher
than 90% shows that the volume of the retentate can be
small compared to the large amount of the PhWW influent.
Final Step –
Nanofiltration and Reverse Osmosis
The feed sample for the last step of the treatment
(NF/RO treatment) was fractions (10 L) of the whole
amount of permeate after the nanofiltration treatment with
HL membrane. The results of step 3 are presented in Table
2. The differences between the initial content of the step 2
permeate (effluent 2) and the feed concentration values in
Table 2 (2
nd
column) were caused by the changing separa-
tion effect during batch circulation mode of step 2. Namely,
the feed during step 2 became more and more concentrated
and therefore the membrane rejection gradually decreased,
which is a well-known effect in batch membrane processes
[27, 28].
The last two columns of Table 2 present the MCL
S
val-
ues for discharging the treated water to a sewer system or
natural aquifers (surface water), according to Croatian
Environmental law NN 94/2008. The data in Table 2 obvi-
ously show that the reverse osmosis XLE membrane pro-
vided the highest COD (97.1%), TOC (92.2%) and the con-
ductivity (96.2%) reduction in the NF/RO process, while
the nanofiltration NF270 membrane showed the lowest
efficiency (79.8%, 63.3%, and 93.4%). This also is in
agreement with the MWCO values and pore sizes of the
investigated membranes. According to Košutić et al. [29],
pore sizes were 0.67 nm for XLE, 0.81 nm for NF90, and
0.90 + 1.56 nm for NF270, while the membranes’ thin layer
porosity (pore size and pore size distribution) were deter-
mined indirectly by the solute transport method using the
fine-pore model. At the operating pressure of 25 bar, the
COD, TOC, and κ values of the permeate (effluent) from
NF90 membrane were 288.1 mg·L
-1
(93.9%), 155.2 mg·L
-1
(90.2%), and 1,835 µS·cm
-1
(94.2%), respectively. The sep-
aration efficiency of the NF90 membrane was very close to
that of the reverse osmosis XLE membrane, because the
active layer structure of the tight NF membrane (NF90) was
at the narrow pore end of the NF separation range. The
results of the other measured parameters show high effi-
ciencies with all the examined membranes.
The obtained fluxes were in agreement with the theory,
because according to the MWCO of the membranes used,
the flux sequence should be J(NF270) > J(NF90) > J(XLE).
The effectiveness of the whole treatment (Fenton, sand
filtration, UF, NF, and RO) is presented in the last column
of Table 3. These results indicate that the combination of
the selected treatments was appropriate for this kind of
highly polluted wastewater, because the reduction of mea-
sured parameters was higher than 90%.
A comparison of the results of the current study with
those obtained in previous research on the use of these
membranes for the distinct type of wastewaters shows good
agreement. The COD reduction in this research is consis-
tent with previous works [30, 31]. There are deviations for
a few percentages, but this was to be expected due to depen-
dency on the wastewater characteristics and operating con-
ditions.
The results obtained in this study show that the PhWW
treated in this manner could be discharged to the sewer sys-
tem, but for discharge to surface waters the approach needs
to be further investigated. The next step of this work will be
to find a treatment to meet MCL
S
for the discharge to the
surface water or natural aquifers.
Combined Methods of Highly Polluted... 1681
Feed NF90 NF270 XLE
MCL
S
Surface water
MCL
S
Sewer system
COD (mg O
2
·L
-1
)
4,725 288.1 952.0 136.4 125 700
Conductivity (µS·cm
-1
) 31,800 1,835 2,100 1,200 - -
TOC (mg C·L
-1
) 1,579 155.2 580.0 123.1 30 -
pH 7.75 8.60 8.06 n.s. 6.50-9.00 6.50-9.50
NH
3
(mg·L
-1
)
471 83.0 336 90 10 -
Cl¯ (mg·L
-1
) 6,966 290 5,886 147 - d.s.
SO
4
2-
(mg·L
-1
)
14.60 0 1.27 0 250 d.s.
Total N (mg·L
-1
) 523 93.0 281 105 10 d.s.
Total P (mg·L
-1
) 0.18 n.s. 0.08 n.s. 2 d.s.
J (L·m
-2
·h
-1
) - 40.31 98.50 26.41 - -
Table 2. The permeate analysis after NF/RO treatment with flux for each membrane and the corresponding MCL
S
values.
n.s. – no sample
d.s. – determined separately for discharge into public sewer system if the collection system has wastewater treatment plant
Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy •

Conclusions
From the results presented above, the following major
conclusions were drawn:
• The combined treatment, including Fenton process,
the sand filter, UF, NF, and RO, used in the treatment
of this pharmaceutical wastewater proved to be effec-
tive.
• The optimum concentrations of Fe
2+
and H
2
O
2
for
Fenton process were 0.6 g·L
-1
and 32 g·L
-1
, respectively,
and the pretreatment was found to be effective in the
reduction of COD, TOC, total N, and total P. It can be
considered as an effective pretreatment of this type of
wastewater.
• The additional decline of measured parameters was
achieved by membrane processes. With NF and RO
membranes, COD, TOC, conductivity, SO
4
2-
, total N,
and total P were lowered for 90-99%, 73-94%, 94-97%,
99-100%, 44-81%, and 75%, respectively. Other para-
meters declined more than 30%.
• The recovery, which was greater than 90%, significant-
ly reduced the volume of retentate (effluent) for further
treatment or disposal.
The treated effluent could be discharged to the sewer
system under the condition that the appropriate wastewater
monitoring and sampling facilities are installed. The waste-
water flow and composition should be measured by the
wastewater producers and checked by the authorities on a
regular basis.
Acknowledgements
This work has been supported by the Croatian Ministry
of Education, Science, and Sport projects: 125-1253008-
3009 (Membrane and adsorption processes for removal of
organic compounds in water treatment) and 125-1253008-
2571 (Water purification and stabilization in large water
supply systems).
References
1. MOHSEN M.S., JABER J.O. Potential of industrial waste-
water reuse. Desalination 152, 281, 2003.
2. MAHMOUD E.K. Chemically enhanced primary treatment
of textile industrial effluents. Pol. J. Environ. Stud. 18, 651,
2009.
3. GINOS A., MANIOS T., MANTZAVINOS D. Treatment of
olive mill effluents by coagulation-flocculation-hydrogen
peroxide oxidation and effect on phytotoxicity. J. Hazard.
Mater. 133, 135, 2006.
4. LEI L., GU L., ZHANG X., SU Y. Catalytic oxidation of
highly concentrated real industrial wastewater by integrated
ozone and activated carbon. Appl. Catal. A. 327, 287, 2007.
5. SAN SEBASTIÁN M., AMP, X, NEZ N., FERNÁNDEZ
J.F., GULS, SEGURA X.F., FERRER A.S. Pre-oxidation of
an extremely polluted industrial wastewater by the Fenton’s
reagent. J. Hazard. Mater. 101, 315, 2003.
6. MUTAMIM N.S.A., NOOR Z.Z., HASSAN M.A.A., OLS-
SON G. Application of membrane bioreactor technology in
treating high strength industrial wastewater: a performance
review. Desalination 305, 1, 2012.
7. GARCIA-CASTELLO E., CASSANO A., CRISCUOLI A.,
CONIDI C., DRIOLI E. Recovery and concentration of
polyphenols from olive mill wastewaters by integrated
membrane system. Water Res. 44, 3883, 2010.
8. PERDIGÓN-MELÓN J.A., CARBAJO J.B., PETRE A.L.,
ROSAL R., GARCÍA-CALVO E. Coagulation-Fenton cou-
pled treatment for ecotoxicity reduction in highly polluted
industrial wastewater. J. Hazard. Mater. 181, 127, 2010.
9. STHIANNOPKAO S., SREESAI S. Utilization of pulp and
paper industrial wastes to remove heavy metals from metal
finishing wastewater. J. Environ. Manage. 90, 3283, 2009.
10. YASAR A., TABINDA A.B. Anaerobic treatment of indus-
trial wastewater by UASB reactor integrated with chemical
oxidation processes; An overview. Pol. J. Environ. Stud. 19,
1051, 2010.
11. ÜSTÜN G.E., SOLMAZ S.K.A., BIRGÜL A. Regeneration
of industrial district wastewater using a combination of
Fenton process and ion exchange – A case study. Resour.
Conser. Recycl. 52, 425, 2007.
12. BADAWY M.I., ALI M.E.M. Fenton's peroxidation and
coagulation processes for the treatment of combined indus-
trial and domestic wastewater. J. Hazard. Mater. 136, 961,
2006.
13. GALIL N.I., LEVINSKY Y. Sustainable reclamation and
reuse of industrial wastewater including membrane bioreac-
tor technologies: case studies. Desalination 202, 411, 2007.
14. BÓDALO A., GÓMEZ J.L., GÓMEZ E., HIDALGO A.M.,
ALEMÁN A. Viability study of different reverse osmosis
membranes for application in the tertiary treatment of wastes
from the tanning industry. Desalination 180, 277, 2005.
15. LAU W.-J., ISMAIL A.F. Polymeric nanofiltration mem-
branes for textile dye wastewater treatment: Preparation,
performance evaluation, transport modelling, and fouling
control - a review. Desalination 245, 321, 2009.
16. VOURCH M., BALANNEC B., CHAUFER B., DOR-
ANGE G. Treatment of dairy industry wastewater by
reverse osmosis for water reuse. Desalination 219, 190,
2008.
17. PERA-TITUS M., GARCıA-MOLINA V., BAÑOS M.A.,
GIMÉNEZ J., ESPLUGAS S. Degradation of chlorophe-
nols by means of advanced oxidation processes: a general
review. Appl. Catal. B. 47, 219, 2004.
1682 Dolar D., et al.
Table 3. Overall effectiveness of the treatment.
Raw water Permeate
Conc. R/%
COD (mg O
2
·L
-1
)
25,000 96.2-99.5
Conductivity (μS·cm
-1
) 40,000 94.7-97.0
TOC (mg C·L
-1
) 4,940 88.3-97.5
NH
3
(mg N·L
-1
)
170 -
Cl¯ (mg·L
-1
) 7,300 19.4-98.0
SO
4
2-
(mg·L
-1
)
520.0 99.7-100
Total N (mg·L
-1
) 4,054 93.1-97.7
Total P (mg·L
-1
) 6.96 98.8
Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy •

18. GONZÁLEZ O., SANS C., ESPLUGAS S.
Sulfamethoxazole abatement by photo-Fenton: Toxicity,
inhibition and biodegradability assessment of intermediates.
J. Hazard. Mater. b, 459, 2007.
19. KAVITHA V., PALANIVELU K. Destruction of cresols by
Fenton oxidation process. Water Res. 39, 3062, 2005.
20. BEN W., QIANG Z., PAN X., CHEN M. Removal of vet-
erinary antibiotics from sequencing batch reactor (SBR) pre-
treated swine wastewater by Fenton's reagent. Water Res.
43, 4392, 2009.
21. LIHUA S., RUIPING L., SHENGJI X., YANLING Y.,
GUIBAI L. Enhanced As(III) removal with permanganate
oxidation, ferric chloride precipitation and sand filtration as
pretreatment of ultrafiltration. Desalination 243, 122, 2009.
22. UZAL N., YILMAZ L., YETIS U. Microfiltration/
ultrafiltration as pretreatment for reclamation of rinsing
waters of indigo dyeing. Desalination 240, 198, 2009.
23. VAN HOOF S.C.J.M., HASHIM A., KORDES A.J. The
effect of ultrafiltration as pretreatment to reverse osmosis in
wastewater reuse and seawater desalination applications.
Desalination 124, 231, 1999.
24. DOLAR D., KOŠUTIC K., PAVLOVIC D.M., KUNST B.
Removal of emerging contaminants of industrial origin by
NF/RO – A pilot scale study. Desalin. Water Treat. 6, 197,
2009.
25. DOLAR D., KOŠUTIĆ K., VUČIĆ B. RO/NF treatment of
wastewater from fertilizer factory – removal of fluoride and
phosphate. Desalination 265, 237, 2011.
26. Standard Methods for the Examination of Water and
Wastewater, 19
th
edition ed., American Public Health
Association/American Water Works Association/Water
Environment Federation, Washington DC, 1995.
27. HU K., DICKSON J.M. Nanofiltration membrane perfor-
mance on fluoride removal from water. J. Membr. Sci. 279,
529, 2006.
28. VAN DER BRUGGEN B., SCHAEP J., WILMS D., VAN-
DECASTEELE C. Influence of molecular size, polarity and
charge on the retention of organic molecules by nanofiltra-
tion. J. Membr. Sci. 156, 29, 1999.
29. KOŠUTIĆ K., DOLAR D., KUNST B. On experimental
parameters characterizing the reverse osmosis and nanofil-
tration membranes’ active layer. J. Membr. Sci. 282, 109,
2006.
30. GOZÁLVEZ-ZAFRILLA J.M., SANZ-ESCRIBANO D.,
LORA-GARCÍA J., LEÓN HIDALGO M.C. Nanofiltration
of secondary effluent for wastewater reuse in the textile
industry. Desalination 222, 272, 2008.
31. ZHANG Y., PAGILLA K. Treatment of malathion pesticide
wastewater with nanofiltration and photo-Fenton oxidation.
Desalination 263, 36, 2010.
Combined Methods of Highly Polluted... 1683
Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy •

Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy •