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DOW™UF and RO Technology Used
to Produce High Quality Water for the
Beverage Industry in East Europe
Since August 2009, an integrated membrane system using DOW™Ultrafiltration
At-a-Glance and DOW FILMTEC™ reverse osmosis membranes produces 2,160 m3/day of high
LOCATION quality water for the beverage industry in East Europe.
East Europe
Introduction
Project Purpose:
• Supply high-quality water for soft High quality water is required in the beverage
drink production industry, often exceeding the potable water quality
Design Capacity: standards. Bottlers usually use several filtering
2,160 m3/day of RO permeate and other treatment techniques to remove
impurities and standardize the water used to make
Plant Construction:
soft drinks. Reverse osmosis (RO) system is a
• Veolia Water Solutions &
Technologies, VWS Deutschland prevalent technology applied in the beverage
GmbH – BERKEFELD industry. Nowadays, the trend in reverse osmosis
pretreatment is to change from conventional filtration
System key facts:
(usually multimedia filters) to membrane filtration,
• The plant receives raw feed water
from a bore hole. ultrafiltration (UF). The drivers for adopting UF
technology as RO pretreatment are mainly the better
• The treatment process uses an
integrated membrane system filtered water quality and the environmental aspects,
comprised of DOW™ Ultrafiltration such as the ability to decrease chemical consumption
ad DOW FILMTEC™ reverse osmosis
and sludge quantities. In addition, UF pretreatment
membranes. Figure 1. Photograph of generic soft
is becoming increasingly cost competitive. drinks. Source: iStockphoto
• Intermittent sanitization of the RO
system is done using the non-
oxidative biocide, DBNPA. The plant described in this document can be considered as an example for such an
application. The plant is located in East Europe, receiving raw water from a bore. The water
• The RO permeate shall contain a
bromide content below 0.1 mg/L. treatment process includes an integrated membrane system using DOW™ Ultrafiltration
and DOW FILMTEC™ reverse osmosis membranes. Intermittent offline sanitization
Performance:
of the RO system is done using the non-oxidative biocide, DBNPA (2,2, dibromo-
• Flow and rejection performances
3-nitrilo-proprionamide). The product water is used for the production of soft drinks.
of the ultrafiltration and reverse
osmosis units have been as expected
and constant since startup in August
2009.
• Low and constant pressure drop
and constant normalized flow of the
reverse osmosis system throughout
operation time.
• Intermittent sanitization of the
system as well as good quality of the
ultrafiltration filtrate have allowed
the reverse osmosis system to
remain free of particulate fouling and
biofouling.
• Required removal of salt and
bromide has been reliably achieved.
Time in operation:
Since August 2009
Figure 2. Photograph of two UF skids. Courtesy of VWS Deutschland GmbH – BERKEFELD
Plant Description Table 1. Raw water quality range
The water treatment process is presented in Figure 3. The plant Raw Water
Parameter Unit Quality Range
receives raw feed water from a bore hole. The details of the
average feed water quality are presented in Table 1. The feed Temperature ºC 10–18
water first passes through a degasifier (trickling deaerator), Conductivity µS/cm 5000–7000
which removes hydrogen sulfide (H 2S) from the water. The
pH 7.5–8.5
water is then fed to a self-cleaning filter of 250µm screen
Total Hardness meq/l 15
size to remove big particles and safeguard the downstream
ultrafiltration fibers from mechanical damage. The ultrafiltration Turbidity FNU 1–25
system is divided in 4 parallel lines, each line consists of 18 Bromide mg/l 7.1–8.5
DOW™ Ultrafiltration modules. The DOW™ Ultrafiltration module Silica (SiO2) mg/L 17.2
type used is the 2860 module type, featuring 51 m2 of active
area. The UF system is operated at a flux of 86 l/h/m2 and an
average recovery 92%. The UF system cleaning protocol is Table 2. UF system cleaning protocol
shown in Table 2. The UF system was oversized to account
Backwash Acidic CEB1 CIP2
for potential events of high turbidity. After the UF process,
two break tanks are used to store ultrafiltration filtrate. The Depends on feed
UF filtrate is used to feed the RO system covered under the water turbidity:
scope of this study and other existing treatment processes. Frequency • Turb: < 5 NTU: 120 min 72 hours
• Turb: 5 –10 NTU: 72 min Not
An antiscalant is added and cartridge filters are installed
• Turb: 10 –20 NTU: 43 min needed
before the reverse osmosis unit. These safety filters, with • Turb: 20 – 30 NTU: 33 min since
5 µm pore size, provide additional protection to the high startup
pressure pumps and reverse osmosis membranes. The reverse Chemical Every 12th backwash 600 mg/l
osmosis unit under this study is divided in four identical trains. 10 ppm NaOCI is added of HCI
Each train consists of seven pressure vessels in a 4:2:1 array.
1
CEB: Chemical Enhanced Backwash
Each of the pressure vessels houses four DOW FILMTEC ™ 2
CIP: Cleaning In Place
SW30XLE-400i elements. Seawater membranes are used in
this application to maximize salt rejection and to safely remove
the bromide content from the feed water below 0.1 mg/L. The
reverse osmosis system is operated at an average system
flux of 22 l/h/m2 and a recovery of 80%. The Reverse Osmosis
permeate is pumped into another degasifier (trickling deaerator)
to remove CO2. Additionally, a pH adjustment is conducted.
Finally, the water passes through activated carbon filters,
fine filters of 1 mm pore size and through an ultraviolet (UV)
disinfection system before being used in the final product.
Degasifier Self-cleaning Ultrafiltration UF Safety Reverse
Bore Hole for H2S Filter System Filtrate Cartridge Osmosis
Reduction 250 µm 0.03 µm Water Tank Filter 5 µm System
UV Fine Activated RO Degasifier
Product Water Disinfection Filter Carbon Permeate + pH
1 µm Filter Water Tank Adjustment
Figure 3. Process flow diagram of the plant
DOW™ UF and RO Technology Used
to Produce High Quality Water for the
Beverage Industry in East Europe
Table 3. Summarized UF and RO system information
Total Capacity Operating Recovery Number of Product Total Number
Unit (m3/h) Flux (l/m2h) % Trains/Stages Installed of Modules
Ultrafiltration 316a 86 92b 4 DOW™ UF 2860 Module Type 72
Reverse Osmosis 90 22 80 4/3 DOW FILMTEC™ SW30XLE-400i 112
a
UF gross filtrate flow. The downstream RO system under this study is fed with only a part of the total UF filtrate flow (112.5 m3/h)
b
UF recovery (related to UF feed)% of all three UF trains on duty: UF filtrate net flow / UF Feed flow · 100
The reverse osmosis membranes did not need any CIP during
the first 8 months of operation. However, each RO line receives
a daily offline flushing with the non-oxidizing biocide DBNPA
in order to prevent the occurrence of biogrowth on the mem-
branes surface.
The normalized permeate flow (Figure 6) has been very constant
at around 23 m 3/h, as expected by design. The permeate
quality has been good and stable. The normalized salt passage
has been as expected at around 0.89% (Figure 6). Additionally,
bromide concentration in the permeate stream has been
always around 0.05 mg/l, safely below the maximum limit
of 0.10 mg/l. The normalized pressure drop across the three
stages has been stable at a low level of around 1.5 bar
throughout the reported time of operation (Figure 7). This is
an indication of absence of particulate or biofouling on the RO
Figure 4. Photograph of an RO rack. Courtesy of VWS Deutschland
GmbH – BERKEFELD
membranes. This can be mainly attributed to the good quality
feed water provided by the ultrafiltration membranes and to
the good operation practices as well as the anti-biofouling
Plant Performance
preventive actions done by the operators.
During the first eight months of operation the ultrafiltration
membranes DOW™ UF SFP2860 have been operating at the
design flux of 86 l/h/m 2. In Figure 5 the normalized TMP as
well as the normalized permeability are depicted for the time
frame November 2009 – March 2010. During this period the
permeability faced some fluctuation reaching values as high
as 160 l/h/m 2. During February – March 2010 the normalized
permeability was relatively stable at high values around 118 l/h/
m2. The designed start-up transmembrane pressure (TMP) was
0.5 bar and after eight months of operation the TMP is found
stable at around 0.7– 0.8 bar. The current backwash and CEB
programs are effective in maintaining the TMP and a relatively
high permeability. No Cleaning In Place (CIP) operations have
been required during these first eight months of operation.
Additionally, the UF filtrate water quality has been constant
and of good quality. UF filtrate turbidity values have been Figure 5. Ultrafiltration performance: Normalized TMP and Normalized permeability
determined below 0.1 NTU.
CONCLUSION
Since August 2009, the plant reliably supplies 2,160 m3/day
of high quality water for a soft drink production factory located
in Eastern Europe. The system uses an integrated membrane
system including DOW ™ Ultrafiltration 2860 modules and
DOW FILMTEC™ SW30XLE-400i reverse osmosis membranes.
Seawater type membrane elements are used to maximize salt
rejection and safely remove bromide from the water. The flow
and rejection performances of the UF and RO units have been
as expected and constant since the start-up. Additionally, the
good UF filtrate quality as well as the intermittent offline
sanitization of the system by DBNPA enabled to maintain the
RO system free of particulate fouling and biofouling. This
has been demonstrated by the low and constant pressure
drop and the constant normalized flow of the RO system
Figure 6. RO performance: Normalized permeate flow and normalized salt passage
throughout the operation time.
For more information about DOW Ultrafiltration and FILMTEC™
reverse osmosis membranes, including all scientific data and
supporting reference materials, call the Dow Water & Process
Solutions business:
Lenntech
Figure 7. RO performance: Normalized pressure drop across the three stages
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info@lenntech.com Tel.
Tel. +31-152-610-900
+31-152-610-900
www.lenntech.com
www.lenntech.com Fax.
Fax.+31-152-616-289
+31-152-616-289
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