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Tertiary Treatment of Pharmaceuticals and Personal Care products by Pretreatment and Membrane Processes


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A lab-scale pretreatment system and various membrane systems were investigated in their efficiencies in the removal of eight pharmaceuticals and personal care products (PPCP) compounds from secondary wastewater effluent. The targeted pharmaceutical compounds in this study included acetaminophen, atenolol, carbamazepine, clofibric acid, erythromycin-H2O, gemfibrozil, ibuprofen and sulfamethoxazole because of their high detection frequencies in municipal wastewater treatment plants. The highest PPCP concentrations in municipal wastewater secondary effluents were clofibric acid (240-296 ng L-1), ibuprofen (263-293 ng L-1) and sulfamethoxazole (255-293 ng L-1). Among the various pretreatment processes, granular activated carbon (GAC) was found to be highly-effective in removing the targeted pharmaceuticals by adsorption except for gemfibrozil, ibuprofen and clofibric acid. Microfiltration (MF) and ultrafiltration (UF) membranes are capable of removing suspended solids in wastewater, but as it is difficult to retain PPCPs by size exclusions; this contributed less than 10% removal efficiency. It was also observed that hydrophobic compounds (log Kow > 3) were difficult to remove using UF and MF membranes. The results of this study demonstrate that reverse osmosis (RO) can effectively remove nearly all of the pharmaceuticals (83-99%). In particular, the RO removal mechanisms are emphasized because of their utmost important role in eliminating micro-pollutants
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Sustain. Environ. Res., 21(3), 173-180 (2011) 173
Kok-Kwang Ng, Angela Yu-Chen Lin, Tsung-Hsien Yu and Cheng-Fang Lin*
Graduate Institute of Environmental Engineering
National Taiwan University
Taipei 106, Taiwan
Key Words: Pharmaceuticals, pretreatments, ultrafiltration, microfiltration, reverse osmosis
A lab-scale pretreatment system and various membrane systems were investigated in their
efficiencies in the removal of eight pharmaceuticals and personal care products (PPCP) compounds
from secondary wastewater effluent. The targeted pharmaceutical compounds in this study included
acetaminophen, atenolol, carbamazepine, clofibric acid, erythromycin-H2O, gemfibrozil, ibuprofen
and sulfamethoxazole because of their high detection frequencies in municipal wastewater treatment
plants. The highest PPCP concentrations in municipal wastewater secondary effluents were clofibric
acid (240-296 ng L-1), ibuprofen (263-293 ng L-1) and sulfamethoxazole (255-293 ng L-1). Among
the various pretreatment processes, granular activated carbon (GAC) was found to be highly-
effective in removing the targeted pharmaceuticals by adsorption except for gemfibrozil, ibuprofen
and clofibric acid. Microfiltration (MF) and ultrafiltration (UF) membranes are capable of removing
suspended solids in wastewater, but as it is difficult to retain PPCPs by size exclusions; this
contributed less than 10% removal efficiency. It was also observed that hydrophobic compounds (log
Kow > 3) were difficult to remove using UF and MF membranes. The results of this study
demonstrate that reverse osmosis (RO) can effectively remove nearly all of the pharmaceuticals (83-
99%). In particular, the RO removal mechanisms are emphasized because of their utmost important
role in eliminating micro-pollutants.
*Corresponding author
As human population continues to increase and
economies grow, the demand on limited water re-
sources are expected to rise tremendously in the com-
ing decades. Therefore, water recycling or water rec-
lamation will be the future development in developing
water purification technology to ensure the reliable
quantities and qualities of water for public use. None-
theless, several studies have demonstrated that various
pharmaceuticals and personal care products (PPCPs)
are persistent in the secondary effluent and in natural
waters at ng L-1 to µg L-1 concentrations [1-4]. For ex-
ample, 57 PPCP compounds were detected at four
Taiwanese wastewater treatment plants (WWTP), and
while non-steroidal anti-inflammatory drugs, estro-
gens and caffeine have higher removal efficiencies
(72-100%) by the wastewater treatment process, sev-
eral antibiotic groups are still persistent and present in
the secondary effluents [5]. If their elimination in
WWTPs is not complete, the trace level concentra-
tions may pose potential risks to human health and al-
so to the terrestrial, marine and aquatic ecosystems
[5,6] especially during water reclamation process.
Therefore, the monitoring and elimination of PPCPs
in WWTP effluent has become an important and
pressing matter in water reclamation treatment and
Pretreatment technologies have been tested for
their ability to reduce membrane fouling for the poten-
tial to increase the membrane lifetime and thus de-
creases the operating costs [7,8]. Granular activated
carbon (GAC) and powdered activated carbon (PAC)
have been reported to be commonly used in the ad-
sorption of dissolved solids from the wastewater ef-
fluent [8] and are efficient in removing polar pharma-
ceutical compounds [9]. Synder et al. [10] also re-
ported that PAC and GAC have the capability to re-
move more than 90% of PPCPs in drinking water fa-
cilities. Shon et al. [8] studied microfiltration (MF),
ultrafiltration (UF) and reverse osmosis (RO) using
different physical and chemical pretreatment proc-
174 Sustain. Environ. Res., 21(3), 173-180 (2011)
esses and found that MF and UF mainly remove sus-
pended solids (SS) from the water; meanwhile, PAC
must be added to ensure that RO has sufficient filtra-
tion performance.
Numerous studies have demonstrated that the
membrane technology can be easily applied to remove
natural organic matters (NOM), inorganic compounds
and microorganisms from raw water [11,12], which
can also be used in water reclamation applications.
Currently, in the direct filtration of secondary effluent
from wastewater treatment plants, membrane tech-
nologies such as MF, UF, nanofiltration (NF) and RO
is widely utilized for the main purpose of wastewater
recycling [10,13]. The application of RO water recla-
mation has been the focus of attention of many studies.
However, many manufacturers of PPCPs and allied
industries are looking for better ways in treatment to
ultimately eliminate the presence of PPCPs in the wa-
ter environment [14,15]. Synder et al. [10] confirmed
that most of the PPCPs were hardly eliminated when
passing through the UF system. NF (> 99% removal
efficiency) and RO (90-99% removal efficiency) are
required if membrane filtration constitutes an essential
post-treatment technique. The degree of removal effi-
ciency is directly related to the membrane characteris-
tics and molecular properties associated to its targeted
compounds [10]. Moreover, the combination of MF or
UF with RO as secondary effluent post-treatment
seems to be efficient in removing the PPCPs in the
aquatic environment [4,10,16].
To our knowledge, very little information is
available on commercial pretreatment techniques us-
ing low pressure membranes combined with pretreat-
ments for the removal of PPCPs. In this study, the per-
formances of pretreatment technologies, lab scale of
MF and UF, and RO membranes in removing the
eight targeted PPCPs were investigated. The most
suitable pretreatment technologies for MF and UF
with the combination of RO membrane in eliminating
PPCPs were also evaluated.
1. Reagents and Selected PPCPs
All chemicals and analysis standards used were
of the highest purity commercially available. In this
study, eight PPCPs were selected as the targeted com-
pounds (Table 1) purchased from Sigma Aldrich (St.
Louis, MO). All the targeted compounds were chosen
because of their high detection frequencies and high
influent concentrations in WWTPs [17].
2. Sample Collection and Preservation
Wastewaters (secondary effluent) were collected
from the Dihua wastewater treatment plant which is
one of the largest secondary wastewater treatment
plants in Taipei City. A total of 80 L of secondary ef-
fluent were collected and stored in ice-packed con-
tainers. After collection, the wastewater was shipped
to the laboratory immediately and fed to different
types of pretreatments such as polymer, PAC, GAC,
ion exchange (IE), fiber filter (FF) and membrane
processes (UF, MF and RO). Triplicate samples from
the selected points in the lab-scale pretreatments and
membrane processes were collected in 1-L silanized
amber glass bottles and 8 mL of 0.125 M EDTA-2Na
were added to the amber glass bottles to prevent the
adsorption of compounds on the glass. All samples
were vacuum-filtered through 0.22 µm cellulose ace-
tate membrane filters (Advantec, Toyo Roshi Kaisha,
Japan) and immediately adjusted to pH 4 with 1 N sul-
furic acid and then were refrigerated at 4 °C until
3. Analytical Methods
For the targeted PPCP analysis, the Oasis HLB
cartridge with 500 mg of sorbent and 6 mL capacity
(Waters, Milford, MA, USA) was conditioned with 6
mL of methanol and 6 mL of deionized water (DI). A
400-mL sample was spiked with a flow rate of 3-6 mL
min-1 followed by rinsing with 6 mL of DI and then
dried by nitrogen stream. The analytes were eluted
with 4 mL of methanol and 4 mL of 50% (v/v) metha-
nol-diethyl ether. The collected elutes were concen-
trated over a continuous and constant flow of nitrogen
gas at 37 °C, reconstituted with 0.4 mL of 25% aque-
ous methanol and then filtered through a 0.45 µm
polyvinylidene fluoride membrane filter before liquid
chromatography/tandem mass spectrometry (LC-
Table 1. Target PPCP compounds
Name Acronym MW pKa
a Log Kow
b K
H (atm-m3 mol-1) Effective Diameterc (nm)
Acetaminophen ACT 151.2 9.4 0.46 6.42 × 10-13 0.59
Atenolol ATL 266.3 9.5 0.16 1.37 × 10-18 0.75
Carbamazepine CBZ 236.3 0.37 2.45 1.08 × 10-10 0.71
Clofibric acid CFA 214.6 NA NA 2.19 × 10-8 0.68
Erythromycin-H2O ERM-H2O 734.5 8.8, 8.9 3.00, 3.06 5.42 × 10-29 1.17
Gemfibrozil GEM 250.3 4.8 4.77 1.19 × 10-8 0.73
Ibuprofen IBU 206.3 4.5, 4.9 3.97, 3.50 1.58 × 10-7 0.67
Sulfamethoxazole SMX 253.3 2.0, 5.5 0.50, 0.89 6.4 × 10-13 0.73
a, bData are from references: [5,10,21].
Ng et al.: Tertiary Treatment of PPCPs 175
MS/MS) analysis. Surrogate standards (13C6-
sulfamethazine, atenolol-d7, josamycin and ibuprofen-
d3) were added to the initial samples and were fol-
lowed through the entire extraction and analytical pro-
cedures. The concentrations of the targeted pharma-
ceuticals were analysed using an Agilent 1200 module
(Agilent Technologies, Palo Alto, CA) equipped with
a ZORBAX Eclipse XDB-C18 column (150 × 4.6 mm,
5 μm) coupled to a Sciex API 4000 quadruple mass
spectrometer (Applied Biosystems, Foster City, CA)
equipped with a turbo ion spray source. All the com-
pounds have 0.5 ng L-1 quantification limits except for
atenolol, carbamazepine, and erythromycin-H2O with
1.0 ng L-1 and ibuprofen with 2.5 ng L-1. The recover-
ies of the targeted compounds were in an acceptable
range from 74 to 130%. The detailed quantification
procedure was reported by Lin et al. [5,17].
All samples were also analyzed for pH value,
chemical oxygen demand (COD), turbidity, ammonia,
nitrate, phosphate, SS, Escherichia coli and total dis-
solved solids (TDS). The pH value, TDS and turbidity
were measured with a HACH (Loveland, CO) HQ20
Portable Dissolved Oxygen/pH Meter (Cat. No.
51825-00), a HACH SecsION5 Conductivity Meter
and a HACH 2100P Turbidimeter, respectively. COD,
+, NO3
- and PO4
3- were analysed according to the
HACH closed reflux colorimetric method, Nessler
method, cadmium reduction method and persulfate di-
gestion method with the use of a HACH (DR 2800)
spectrophotometer (HACH, 2005). The concentration
of SS and E. Coli in the wastewater was analyzed us-
ing the Standard Method [18].
4. Membrane Reactors Set-up and Testing Units
All the membrane evaluated were performed and
operated in a lab-scale system. Table 2 summaries the
membrane specifications for low pressure membranes
(MF and UF) and high pressure membrane (RO) in
this study. The operation of the membranes was ac-
cording to the guidelines and manuals of the mem-
brane companies. The membranes were operated with
DI to reach a steady state for 8-12 h before operating
with the test solutions in order to prevent the pre-
compaction at the same pressure. The membranes
were cleaned by the relaxation process, backwashing
and clean in place process (NaOCl). The membrane
condition was checked periodically by forcing the air
inside the membrane fibres in a DI tank and the mem-
brane was changed when bubbles were detected.
5. Pretreatments
The processes of the pretreatments consist of co-
agulation by polymer (Sigma-Aldrich Corp., St. Louis,
MO), FF (Aqua-win MB-01, Watertec Co., Kaohsiung,
Taiwan) with 1 µm, IE resin (Max Water Flow, Con-
cord, ON), GAC (Flow-Pur T33-CG, Ellsworth, OH)
and PAC (Taipei Chemical Industry Co., Taipei, Tai-
wan). A series of jar tests were used for polymer co-
agulation (1-4 mL Poly(diallyldimethylammonium)
chloride, PolyDADMAC with rapid mixing (100 rpm)
for 2 min and subsequently slow mixing (30 rpm) for
20 min and allowed to settle in 30 min. PAC was
added at a dose of 10 mg L-1 with a 2-h contact time
(based on the bench scale test). The diameters of GAC
and IE column were 8 cm and GAC had a service life
of approximately 9500 L. The secondary effluent in
the 5-L amber glass bottle was pass through the FF,
GAC and IE resin respectively by means of a peristal-
tic pump separately at a filtration rate of 140 mL min-1
and the resulting effluents from the pretreatments
were collected for further studies.
The pretreatment methods were compared and
evaluated using water quality analysis as pretreatment
selection criteria for UF and MF membranes. The re-
sults are illustrated in Table 3. Among the pretreat-
ment methods in this study, FF (1 µm) and polymer
were given strong consideration as the best pretreat-
ment methods from the economic point view to the
UF and MF membranes since low pressure mem-
branes (MF and UF) are able to remove up to 80 and
55% of SS, respectively and may be able to reduce the
cake layers on the membrane surfaces [19].
Table 2. Specifications of MF, UF and RO membrane
Microfiltration (MF) Ultrafiltration (UF) Reverse Osmosis (RO)
Manufacturer Kubota GE Zenon ZW-1 DOW BW-30 1812
Membrane type Plate and frame Hollow fibers Spiral wound
Membrane material Chlorined PE PVDF Polyamide (PA)
Nominal pore size 0.4 µm 0.04 µm 0.1 nm
Membrane area (m2) 0.1 0.046 0.465
Element size (mm) L: 210 × W: 290 × T: 60 L: 172 × D: 50 L: 305 × D: 45
Designed pH range 2-11 2-11 4-11
Operating pressure (kPa) 5-10 10-55 600-1000
Design flux (L m-2 h-1) 8-20 18-40
Recovery (%)
176 Sustain. Environ. Res., 21(3), 173-180 (2011)
Table 3. Secondary effluent of water quality after pretreatments
Analytes Secondary
Effluent GAC PAC IE Resin Polymer
Fiber Filter
(1 µm)
pH 7.1 7.7 6.5 7.1 6.7 6.5
COD (mg L-1) 18 ± 2 14 ± 2 7 ± 1 11 ± 2 9 ± 2 16 ± 3
Turbidity (NTU) 1.9 ± 0.4 1.0 ± 0.6 1.2 ± 0.3 0.8 ± 0.2 0.6 ± 0.4 0.4 ± 0.1
NH3-N (mg L-1) 0.19 ± 0.03 0.15 ± 0.02 0.18 ± 0.03 0.16 ± 0.03 0.17 ± 0.05 0.14 ± 0.03
NO3-N (mg L-1) 4.10 ± 0.42 1.90 ± 0.28 3.20 ± 1.13 3.80 ± 1.41 3.70 ± 0.42 3.20 ± 0.28
3- (mg L-1) 2.04 ± 0.13 1.99 ± 0.42 1.75 ± 0.64 2.10 ± 0.09 1.72 ± 0.10 1.85 ± 0.18
SS (mg L-1) 16 ± 1 9 ± 1 12 ± 1 13 ± 3 7 ± 4 3 ± 0
E. coli (CFU 100 mL-1) 3800 3500 NA 3700 3700 3200
TDS (mg L-1) 301 285 146 150 146 141
NA = Not Available
The results for PPCP removal by various pre-
treatments and low pressure membranes is depicted in
Table 4. The presence of compounds in the secondary
effluent indicated their incomplete removal and also
showed that residuals persisted after the WWTP
treatment process. Clofibric acid (240-296 ng L-1),
ibuprofen (263-293 ng L-1) and sulfamethoxazole
(255-293 ng L-1) in the municipal wastewater secon-
dary effluent were detected in relatively higher con-
centrations. Activated carbon (GAC and PAC) can
eliminate the PPCPs effectively and the main removal
mechanism is based on hydrophobic interaction which
is suited for non-polar organic compounds [3]. In the
study described here, both GAC and PAC which could
significantly remove the PPCPs, and GAC was found
to be highly-effective in eliminating the targeted
PPCPs (acetaminophen, atenolol, carbamazepine,
erythromycin-H2O and sulfamethoxazole) by more
than 95%. The removal efficiency of the PAC was
less than that of the GAC possibly because the PPCP
removal efficiency might be depend on the PAC dose
and contact time in the water [10]. The IE resin, po-
lymer and FF did not show good removal efficiencies,
but a slightly higher degree of removal efficiency was
observed for atenolol and erythromycin-H2O while the
rest of the PPCPs were not removed by the IE resin
and FF.
The results in Table 4 show that the MF and UF
had little capability in removing PPCPs. The removal
mechanisms might be attributed to hydrophobic ab-
sorption on the membrane surface area [20], however
the targeted PPCPs in this study did not follow the
removal mechanism; therefore, this led to less than
10% of the initial compound removal in the permeate
except for acetaminophen (< 25%). MF and UF have
the capability to remove SS and could disinfect
wastewater, but it is hard to retain PPCPs by size ex-
clusions [3,10]. The effective diameters of these
PPCPs compounds are in the range of 0.6-1.2 nm (Ta-
ble 2). Hence, MF and UF membrane with a nominal
size of 400 and 36 nm, respectively, are not able to
remove all the targeted PPCPs compounds. Moreover,
it was found that the hydrophobic compounds (log
Kow > 3) were difficult to remove with MF and UF
membranes. The finding shows that the GAC and
PAC were more effective in removing the targeted
compounds than other pretreatments and low pressure
membranes (MF and UF) and all the pretreatments
and low pressure membranes (MF and UF) have to be
combined with the RO to achieve better removal effi-
ciency of the PPCPs.
Table 5 clearly shows that the RO membranes
were effective on reducing the concentration of PPCPs.
Trace levels of compounds were still detectable in the
RO permeates. In the presence of RO, target PPCPs
compounds removal efficiencies were excellent (83-
99%), indicating that the RO membrane was sufficient
to remove these pollutants with any combination of
pretreatments or low pressure membrane (MF and UF).
The results shows the RO membrane had greater re-
tention than the MF and UF membranes, which was
presumably because more size exclusion contributed
to the retention for the RO membrane (0.1 nm). Since
almost all the PPCP compounds have a molecular
weight (MW) of greater than 0.5 that necessitates the
use of RO in order to reduce PPCPs concentration in
wastewater [21].
PPCPs can be removed by RO because the nega-
tive charged membrane possibly plays a role in charge
exclusion mechanism. For example, negatively
charged pharmaceutical compounds such as car-
bamazepine, gemfibrozil, sulfamethoxazole and clofi-
bric acid were recorded with higher removal efficien-
cies (> 90%) as compared to more positively charged
PPCPs which may be due to the interactions with the
membrane surface [22]. The results are also supported
by Xu et al. [23] who showed that negatively charged
compounds were easy to eliminate on a negatively
charged membrane surface. Besides, speciation of mo-
lecules, i.e., the charged property of PPCPs is highly
dependent on solution pH value. For example, while
the solution pH level is above the isoelectric point of
the membranes, the membrane is negatively charged
and it may increase the rejection of negatively
Ng et al.: Tertiary Treatment of PPCPs 177
Table 4. Percentage of PPCPs removal by various pretreatments and low pressure membranes
Sec. Eff. GAC PAC IE Resin Polymer Fiber Filter
(1 µm) UF MF
Mean ± SD
(ng L-1)
Mean ± SD
(ng L-1)
(RE, %)
Mean ± SD
(ng L-1)
(RE, %)
Mean ± SD
(ng L-1)
(RE, %)
Mean ± SD
(ng L-1)
(RE, %)
Mean ± SD
(ng L-1)
(RE, %)
Mean ± SD
(ng L-1)
(RE, %)
Mean ± SD
(ng L-1)
(RE, %)
ACT 32 ± 12 0.6 ± 0.5
9 ± 8
4 ± 2
17 ± 7
24 ± 6
24 ± 6
36 ± 16
ATL 124 ± 8 ND
(> 99)
53 ± 6
(> 99)
80 ± 18
89 ± 12
121 ± 10
119 ± 17
CBZ 83 ± 29 ND
(> 99)
31 ± 26
59 ± 2
103 ± 2
97 ± 3
95 ± 6
102 ± 5
CFA 268 ± 28 72 ± 41
230 ± 13
321 ± 8
227 ± 1
287 ± 4
273 ± 2
281 ± 21
ERM-H2O 15 ± 2 ND
(> 99)
(> 99)
(> 99)
16 ± 1
(> 99)
15 ± 1
16 ± 2
GEM 14 ± 2 3 ± 2
9 ± 2
19 ± 1
13 ± 2
19 ± 2
14 ± 2
14 ± 3
IBU 283 ± 20 121 ± 90
209 ± 10
362 ± 8
279 ± 1
315 ± 8
271 ± 21
264 ± 10
SMX 274 ± 19 ND
(> 99)
116 ± 101
242 ± 1
234 ± 4
238 ± 23
243 ± 34
258 ± 15
Cpd. = compound; Sec. Eff. = secondary effluent; GAC = granular activated carbon; PAC = powder activated carbon; IE = ion
exchanger; UF = ultrafiltration; MF = microfiltration; avg. = average concentration; SD = standard deviation; RE = removal
efficiency; ND = not detected; NR = not removed
Table 5. Percentage of PPCPs removal by membranes filtration
UF + RO MF + RO FF + UF + RO FF + MF + RO P + UF + RO P + UF + RO Process
Mean ± SD
(ng L-1)
(RE, %)
Mean ± SD
(ng L-1)
(RE, %)
Mean ± SD
(ng L-1)
(RE, %)
Mean ± SD
(ng L-1)
(RE, %)
Mean ± SD
(ng L-1)
(RE, %)
Mean ± SD
(ng L-1)
(RE, %)
ACT 5.3 ± 0.1
(> 99)
(> 99)
(> 99)
(> 99)
(> 99)
ATL 3.4 ± 0.3
6.0 ± 0.2
(> 99)
0.8 ± 0.2
(> 99)
10 ± 1
6 ± 1
(> 99)
(> 99)
(> 99)
5 ± 1
(> 99)
(> 99)
CFA 11 ± 4
6 ± 3
5 ±4
5 ± 3
32 ± 2
24 ± 1
(> 99)
(> 99)
(> 99)
(> 99)
(> 99)
(> 99)
(> 99)
(> 99)
2 ± 1
(> 99)
(> 99)
(> 99)
4 ± 1
23 ± 12
32 ± 5
4 ± 1
17 ± 1
SMX 13.3 ± 0.3
27 ± 1
(> 99)
5 ± 2
26 ± 2
25 ± 3
Cpd. = compound; Sec. Eff. = secondary effluent; UF = ultrafiltration; MF = microfiltration; RO = reverse osmosis; FF = fiber filter;
P = polymer; avg. = average concentration; SD = standard deviation; RE = removal efficiency; ND = not detected
charged solutes due to the electrostatic repulsion with
membrane surface [4,23]. As documented by Bellona
et al. [24], membrane properties, feed composition
and operating conditions could affect the rejection of
solute on NF/RO membranes. Size exclusion, charge
exclusion and physico-chemical interactions between
solute, solvent and membrane are the basic mecha-
nisms or explanations for RO rejection.
Hydrophobicity leads to PPCP adsorption onto
the membrane surface and inside the pores; it can dif-
fuse through the RO membrane polymer [25]. In most
cases, the RO membranes may absorb many hydro-
178 Sustain. Environ. Res., 21(3), 173-180 (2011)
phobic compounds (Log Kow >3) and the removal effi-
ciency will increase with the increase of Log Kow val-
ue, which shows that retention of hydrophobic mem-
brane is generally influenced by hydrophobic interac-
tion [24]. For example, erythromycin-H2O, gemfibro-
zil and ibuprofen (Log Kow > 3) are considered as ab-
stemiously hydrophobic and thus the removal effi-
ciency of these three pharmaceuticals was more than
95% and the result was consistent with that obtained
by Al-Rifai et al. [26]. On the contrary, the removal
efficiency of polar charged compounds (lower log Kow)
was found to be better removal in the RO process due
to the interactions with membrane [22,24,27] and the
convection of molecules in hydrophilic charged com-
pounds [28] which depends on the membrane material
and feed solution pH. Additional studies, however, are
needed to validate this observation at pilot-scale or
full-scale membrane utilities to understand the role of
membrane material toward PPCP compounds.
On the other hand, the rejection of hydrophilic
and uncharged molecules (acetaminophen) should be
highlighted, considering their greater affinity towards
water. It was presumed that the adsorption of trace
compounds in the structure of RO would possibly not
occur completely because the RO was new and did not
achieve the steady-state operation for the membrane
material [21]. Therefore, this may explain its limited
rejection on RO membranes (> 83%). In order to
avoid erroneous results especially in the trace concen-
trations of PPCPs, a longer time of membrane filtra-
tion would be required to achieve membrane equilib-
Throughout the duration of experiments, the ob-
served results suggest that the combination of FF, UF
with and RO had achieved an excellent removal for
nearly all the target compounds (> 98%) except for
ibuprofen (< 92%). FF has lower removal efficiency
in eliminating PPCPs, but it is able to remove the sus-
pended matters and colloid particles in the wastewater
before the wastewater enters UF membrane. FF is a
very promising pretreatment in terms of controlling
and reducing UF fouling, and it requires less cleaning
and is being economical to operate. The results give
us a good criterion for selecting pretreatment methods
for the further membrane analysis to remove the
PPCPs and also to reduce the fouling of membrane.
RO was thus shown to be the main application that
was capable of significant rejection of nearly all the
targeted compounds, though compounds at trace lev-
els were detectable in permeates. Consequently, the
fundamental approach can be utilized to evaluate the
potential of PPCP removal by identification of the
compounds in water.
In this work, various pretreatments and mem-
branes (UF, MF and RO) were applied in the removal
of PPCPs from a municipal WWTP with the aim of
water reclamation. PPCPs could be removed by GAC
with the adsorption mechanisms but the MF and UF
membranes had little removal efficiency on the se-
lected PPCPs (< 30%) which were generally governed
by hydrophobic adsorption. Hydrophobic compounds
(log Kow >3) were difficult to remove by pretreatments
and low pressure membranes (MF and UF membrane)
and this led to the poor removal efficiency of the
PPCPs. The mechanism of size exclusion for RO
brought about high rejections (> 83%) for these mi-
cropollutants that have a greater MW cut-off than that
of RO membranes. Besides, the highest removal effi-
ciency in RO process was recorded for negatively
charged pharmaceutical compounds of gemfibrozil,
sulfamethoxazole and clofibric acid. Furthermore, a
steady-state operation for the membrane must be
achieved in order to avoid erroneous results especially
in the trace concentrations of PPCPs. In addition, the
combination of FF, UF with RO membrane had
achieved an excellent removal efficiency (90-99%) in
all the target compounds. The results in this study
provide several additional data although this is a
short-term study using the pretreatments and mem-
brane systems. Therefore, future research efforts
should focus on the studies of the transport of animal
and endocrine disrupting compounds in membrane fil-
tration to establish additional meaningful treatment
The authors would like to thank Water Resource
Agency, Ministry of Economic Affairs of the Repub-
lic of China for financially supporting us in this re-
search under Contract No. MOEAWRA 0980045 and
Contract No. MOEAWRA 0990020.
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Discussions of this paper may appear in the discus-
sion section of a future issue. All discussions should
be submitted to the Editor-in-Chief within six months
of publication.
Manuscript Received: July 20, 2010
Revision Received: October 30, 2010
and Accepted: December 23, 2010
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... MF and UF membranes are efficient in removing solid particles in wastewater, but as it is hard to sustain PPCPs by size exclusions, this contributed less than 10% removal efficiency. It was also noticed that hydrophobic compounds (log Kow > 3) were less likely to be removed by UF and MF membranes [65]. ...
... NF and RO, on the other hand, showed a higher removal efficiency-up to 90%-99% in some cases. The degree of removal efficiency was directly related to the membrane characteristics and molecular properties associated with its targeted compounds [65]. However, even though NF has demonstrated such a promising efficacy, it suffers, in addition to the other three classes of membranes, from the following crucial challenges that hinder their full-scale applications in the environmental field to remove PhACs. ...
Pharmaceuticals and personal care products, and endocrine disruptive compounds, have arisen as a new class of emerging organic micropollutants imposing a great risk on the health of both human and aquatic ecosystems. In spite of the advancements accomplished so far in conventional membrane for water purification, none can be considered as a membrane of choice as each of them is inhibited by at least one drawback or trade-off relating to flux, selectivity, stability, or high cost of fabrication; above all, the critical fouling issue exacerbates the situation and comes to the fore, here. Huge efforts have been made to overcome these obstacles, for instance, by modifying membrane surfaces by chemical grafting with hydrophilic monomers; however, satisfactory antifouling properties have not yet been achieved. By exploiting the distinctive features of nanotechnology, blending membranes with nanoparticles, carbon nanomaterials, nanofibers, self-assembled two-dimensional layer materials, their composites, etc. are proven to exceed all the limitations and attain a satisfactory sustainable membrane technology. Even better, employing the functionalized type of nanomaterials may far surpass their original counterparts in terms of mechanical strength, antifouling tendency, rejection for micropollutants, and antitrade-off between permeability and selectivity. This chapter attempts to shed some light on the nanotechnologies novelties and endeavors notably found in the state-of-the-art membrane-based micropollutant removal technologies.
... Advanced treatment processes usually follow high-rate secondary treatment, which is sometimes referred as tertiary treatment procedures. However, sometimes advanced treatment processes can be combined with primary or secondary treatment or used in place of secondary treatment [23]. The most popular advanced treatment methods are membrane filtration and advanced oxidation. ...
... Different treatment processes, including activated carbon [1,17], nanofiltration [18,19], and reverse osmosis [20] have been reported as effective treatment options for removing different types of pharmaceuticals. However, these treatment processes are considered temporary solutions, as they only move or transfer the pharmaceuticals to the solid phase or concentrate them in a small volume of aqueous solution, which then requires further treatment. ...
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This study investigates the use of ozone as a pretreatment process for water containing pharmaceuticals. Experiments were carried out on synthetic wastewater, surface water, and the effluent of wastewater treatment plant. The degradation efficiencies of four groups of pharmaceuticals (antibiotics, estrogens, acidic, and neutral) were studied, and the effect of ozone dose and pH on the degradation efficiency was monitored. A Microtox™ bioassay test was used to evaluate the change in the toxicity of aqueous solutions before and after ozonation. The efficiency of oxidation of antibiotics, estrogens, and neutral pharmaceuticals increased as the ozone dose and pH increased. Ozone input dose of 188.1, 222.3, and 222.4 mg h−1was found to be optimum yielding the highest oxidation efficiency for the studied pharmaceuticals in synthetic wastewater, surface water and effluent of wastewater treatment plant, respectively. An average specific ozone dose of 2.05 for antibiotics, 1.11 for estrogens, and 1.30 mg O3/mg DOC for neutral pharmaceuticals reduced significantly the acute the toxicity of the water solutions and mineralized more than 40%, 33%, and 23% of DOC in less than 1 min. The kinetics of ozone with pharmaceuticals was modeled for synthetic wastewater as an overall second-order reaction with a rate constant ranging from 103 to 106 M−1 s−1. The results indicate the effectiveness of ozone-based advanced oxidation processes in removing emerging pharmaceuticals from water and wastewater. The results showed that ozonation process is more effective than other conventional oxidation processes (Cl2 and ClO2) in eliminating pharmaceuticals and reducing the toxicity of the effluent water or wastewater. © 2016 American Institute of Chemical Engineers Environ Prog, 2016
Artificial recharge to groundwater with reclaimed water is considered a promising method to alleviate groundwater depletion and over-exploitation. However, the occurrence of fluoroquinolone antibiotics (FQs) was ubiquitous in wastewater, surface water, groundwater and even drinking water threating human health and ecology. In this study, the occurrence of six selected FQs in reclaimed water effluent and their removal by tertiary treatment units were investigated. The overall removal efficiencies in average of the tertiary treatment processes in Beijing and Changzhou were ranging from 21.2% to 55.2%. Activated carbon exhibited better performance for FQs removal than ozone and biological treatment such as membrane bioreactor, anaerobic-anoxic-oxic and biofilter. The results of two pilot study showed that the impact of reclaimed water to groundwater quality in terms of FQs concentration by direct injection in GBD was stronger than surface spreading in Changzhou, which might be due to the recharge strategy and the physical and chemical characteristics of sediment and aquifer soil. The hazard quotient (HQ) values of ofloxacin (OFL) in reclaimed water was up to 12.54, indicating the extreme eco-toxicological risk, while enrofloxacin (ENR) exhibited medium risk. After recharge with reclaimed water, the HQ values of OFL and ENR in groundwater ranged from low to medium ecological risk to the environment. Thus, the FQs in reclaimed water need to be paid more attention during their reuse for groundwater recharge, especially by direct injection. It is suggested that FQs should be considered in the priority substances lists in standards and guidelines of reclaimed water reuse for groundwater recharge to ensure the safety of groundwater.
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The Pharmaceutical Industry produces a wide variety of products in batch or semi-batch processes where the usage of water in many processing equipment plays an important role. The wastewater that is generated from these industries may contain pharmaceutical compounds that are let out in the aquatic environment. The characteristics of pharmaceutical wastewater are clearly mentioned. The wastewater generated in between the processes may contain many chemicals and pharmaceutical compounds that have to be treated. It is very much necessary to analyze the treatment technologies and implement properly, such that the pharmaceutical compounds are disposed of in safe limits. All the various treatments used are presented clearly in this review. Generally, one method employed will not lead to complete removal of contaminants; there must be a combination of the process for efficient remova
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The widespread use and presence of Pharmaceuticals and Personal care products (PPCPs) in aquatic environment throughout the world and their potential biological activity suggest, that understanding how these compounds can influence aquatic ecosystem functions is an important research direction. PPCPs are widely studied and the number of papers published in SCI journals is > 1500 in 2017 itself and > 7000 since 2012. ( The present chapter discusses the classification and possible environmental sources of PPCPs. It also details the fate, pathways, persistence and eco-toxicological profile of these compounds focusing on aquatic environment. The efficiency and limitations of the existing conventional/ advanced water/wastewater treatment systems in the removal of these compounds, is also overviewed to understand the aquatic environmental pathway of PPCPs. The chapter describes the steps towards directives and regulations and the key strategy adopted for the basis of concern.
To recover gold, this work used a novel direct contact membrane distillation (DCMD) reactor with a hybrid electrolytic process. Analytical results demonstrate that permeate flux increased as feed temperature and feed flow rate increased. Permeate flux increased from 2.8 to 17.6 kg m-2 h-1 when temperature increased from 30 to 70 °C, and increased from 9.2 to 19.9 kg m-2 h-1 when the feed flow rate increased from 10 to 50 L h-1. A strong negative correlation between feed conductivity and permeate flux existed. Flux decreased about 21% following an increase in Au wastewater concentration in the feed from 5,600 to 55,000 μS cm-1. The gold and total organic carbon concentrations in- creased as the concentration ratio increased. The Au concentration reached around 165 mg L-1 with a concentrating efficiency exceeding 17-fold. After the DCMD process, 90% of the concentrated gold solution was recovered by electrolysis. Performance recovery rate increased about 20 times from 10.6 to 252 mg A-1 h-1. These positive results show that the new hybrid process integrating a DCMD reactor with electrolysis methods can be applied effectively to treat low concentrations of gold in wastewater.
The effluents from domestic wastewater treatment plants are recognized as important entry routes for pharmaceuticals and personal care products (PPCPs) into the environment. Wastewater treatment processes, which originally were designed and optimized for removal of suspended solids and compounds responsible for eutrophication, are not efficient for removal of many PPCPs. PPCPs vary highly in structure and physicochemical properties and their fate during wastewater treatment are not easily predicted. This chapter presents reported removal data of PPCPs in primary, secondary, and tertiary treatment processes and discusses how chemical properties and operating factors of the different treatment processes influence the removal efficiencies.
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An integrated membrane system pilot study compared microfiltration (MF), ultrafiltration (UF), and conventional treatment as pretreatment strategies for surface water nanofiltration (NF) using spiral-wound elements. MF and UF pretreatment resulted in lower NF fouling rates and longer cleaning intervals compared with those measured following conventional treatment. NF fouling rates evaluated under a wide range of hydrodynamic conditions following conventional treatment suggest NF fouling is more influenced by permeate flux than by feedwater recovery. NF was shown to be capable of meeting all current and anticipated trihalomethane and haloacetic acid regulations.
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A recent study by the Toxic Substances Hydrology Program of the U.S. Geological Survey (USGS) shows that a broad range of chemicals found in residential, industrial, and agricultural wastewaters commonly occurs in mixtures at low concentrations downstream from areas of intense urbanization and animal production. The chemicals include human and veterinary drugs (including antibiotics), natural and synthetic hormones, detergent metabolites, plasticizers, insecticides, and fire retardants. One or more of these chemicals were found in 80 percent of the streams sampled. Half of the streams contained 7 or more of these chemicals, and about one-third of the streams contained 10 or more of these chemicals. This study is the first national-scale examination of these organic wastewater contaminants in streams and supports the USGS mission to assess the quantity and quality of the Nation's water resources. A more complete analysis of these and other emerging water-quality issues is ongoing. Keywords: pharmaceuticals; hormones; other wastewater contaminants; steroids; nonprescription drugs; veterinary pharmaceuticals
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The presence of bioactive trace pollutants such as pharmaceuticals and ingredients of personal care products (PPCPs) in different environmental compartments (rivers, lakes, groundwaters, sediments, etc.) is an emerging issue due to the lack of existing information about the potential impact associated with their occurrence, fate and ecotoxicological effects. Due to the low PPCP concentrations reported in wastewaters (ppb or ppt) and their complex chemical structure, common technologies used in sewage and drinking water treatment plants may not be efficient enough to accomplish their complete removal. Information about physico-chemical characteristics such as acidity, lipophilicity, volatility and sorption potential is a useful tool to understand the different removal patterns observed. In order to perform an accurate overall mass balance along the different units of sewage treatment plants, it is necessary to gather information not only about the presence of micropollutants in the aqueous phase, but also on the fraction sorbed onto solids. Since only some PPCPs are very well eliminated by conventional sewage treatment configurations, new strategies such as modification of operating conditions (e.g. solids retention time), implementation of new technologies (e.g. biomembrane reactors) or additional advanced post-treatment steps (e.g. oxidation, adsorption, membranes) have been suggested for an increased efficiency.
When the first green wave appeared in the mid and late 1960s, it was considered a fea­ sible task to solve pollution problems. The visible problems were mostly limited to point sources, and a comprehensive "end of the pipe technology" (= environmental technology) was available. It was even seriously discussed in the US that what was called "zero dis­ charge" could be attained by 1985. It became clear in the early 1970S that zero discharge would be too expensive, and that we should also rely on the self purification ability of ecosystems. That called for the development of environmental and ecological models to assess the self purifica­ tion capacity of ecosystems and to set up emission standards, considering the rela­ tionship between impacts and effects in the ecosystems. This idea is illustrated in Fig. 0.1. A model is used to relate an emission to its effect on the ecosystem and its components. The relationship is applied to select a good solution to environmental problems by application of environmental technology.
Organic and inorganic micropollutants are rejected by high-pressure membranes, nanofiltration (NF) and reverse osmosis (RO), primarily as a consequence of solute-membrane interactions. These interactions include steric and electrostatic effects that depend on compound properties (e.g., molecular weight (MW) and ionic charge) and membrane properties (e.g., molecular weight cutoff (MWCO) and surface charge (zeta potential)), with the added influence of membrane operating conditions (e.g., recovery). This paper summarizes the rejection trends by several NF and RO membranes for a wide range of organic micropollutants based on hydrophobicity/hydrophilicity (octanol-water partition coefficient, KOW) and charge (neutral or negative), and a more narrow range of inorganic micropollutants in the form of oxyanions (chromate, arsenate and perchlorate) of varying MW and charge. While RO provided greater rejections of micropollutants than NF, observed NF rejections were, in many cases, significant. For oxyanions, rejection was mainly influenced by ionic charge and MW. RO properties generally had little influence while MWCO and zeta potential were both significantly influential for NF. For organic micropollutants, with exception of RO versus NF classifications, membrane properties were less influential than compound properties with greater rejections generally observed with increasing MW, KOw. and (negative) charge.
Reuse of wastewater can help in maintaining environmental quality and relieving the unrelenting pressure on conventional and natural freshwater sources. Membrane processes find an important place in the wastewater treatment for reuse. Nonetheless, reverse osmosis (RO) and nanofiltration (NF), i.e. non-porous membranes require higher operational costs and energy. Thus, in this research NTR 7410 ultrafiltration (UF) membrane which is porous was used without and with pretreatment to treat biologically treated sewage effluent (BTSE). Four different pretreatment methods, namely, ferric chloride (FeCl3) flocculation, powdered activated carbon (PAC) adsorption, flocculation followed by adsorption, and granular activated carbon (GAC) biofilter were used in this study to compare their relative merits. Experimental results indicate that the most suitable pretreatment was flocculation followed by adsorption leading to a total organic carbon (TOC) removal of 90%.
Membrane processes have been used as a key technology for water reclamation and reuse of secondary effluent discharged from municipal wastewater treatment plants. However, its extensive practices are limited due to membrane fouling. To control and manage the membrane fouling properly, pretreatment methods were compared and evaluated. Prior to direct membrane filtration of secondary effluent, the effect of coagulation with alum and ferric sulfate on membrane fouling was investigated using two different ultrafiltration membranes (YM30 and PM30). Membrane filterability was enhanced by addition of alum and ferric sulfate respectively. This was due to the effective destabilization of colloidal particles, which was confirmed by measuring particle size distribution. Soluble foulants present in secondary effluents were entrapped to coagulated flocs. This reduced the concentration of soluble foulants, which lead to a decrease in Rf values. The hydrophobic membrane (PM30) showed high flux declines, whereas the hydrophilic membrane (YM30) showed relatively low flux decline. For the purpose of controlling membrane fouling, a pretreatment using coagulation is more efficient for hydrophobic than hydrophilic membranes. This could give us a good criterion for selecting membrane materials for water reuse practices.
Both natural estrogens and synthetic compounds that mimic estrogen can reach the aquatic environment through wastewater discharges. Because nonylphenol (NP), octylphenol (OP), nonylphenol polyethoxylates (NPE), 17β-estradiol (E2), and ethynylestradiol (EE2) have previously been found to be estrogenic and to occur in wastewater effluents, they were the primary analytes for which the method was developed. Water samples were extracted in situ using solid-phase extraction disks. Analytes were separated by high-pressure liquid chromatography and detected by fluorescence or competitive radioimmunoassay (RIA). Method detection limits (MDLs) using HPLC with fluorescence detection were 11, 2, and 52 ng/L of water for NP, OP, and NPE, respectively. The RIA MDLs for E2 and EE2 were 107 and 53 pg/L, respectively. Samples were collected from four municipal wastewater treatment plants in south central Michigan, eight locations on the Trenton Channel of the Detroit River, MI, and five locations in Lake Mead, NV. Concentrations of NP and OP ranged from less than the MDL to 37 and 0.7 μg/L, respectively. NPE concentrations ranged from less than the MDL to 332 μg/L. Concentrations of E2 and EE2 ranged from less than the MDLs to 3.7 and 0.8 ng/L, respectively.