International

Desalination

Association

“Desalination: The Vision of Today and the Future”

Kader Gaid, Technical Department Veolia Water

Michel Canet, Executive Vice president,Veolia Water

Solutions & Technologies

Keith Craig, Techinal Manager Veolia Water Australia

Comparative Seawater RO Pretreatment

Evaluation Using Existing Plant and Pilot Plant

4 March 2009

4 March 2009

The pre treatment : The key of the success

4 March 2009

Turbidity< 0,5 NTU SDI < 4 No oxidant Low residual metal (Fe, Al) Low organic carbon content No algae cells Low particles counts

Objectives of the Pre treatment

4 March 2009

Mediterranean Sea

Turbidity: 1 – 10 NTU

TOC: 1- 3 mg/L

Algae

T°C : < 27°C

Estuary Europe

Turbidity : 50 NTU

TOC : 20 mg/l

Colour : 50 mg/l Pt/Co

T°C < 20°C

China Sea

TOC: 2- 4 mg/l

Algae

T°C : < 27°C

Turbidity < 5 NTU

TOC < 2 mg/l

T°C < 25 °C

Oman sea & Persic Gulf

Turbidity: 2- 15 NTU

TOC: < 3 mg/L

T°C : 15 – 35°C

algae

Turbidity < 5 NTU

TOC < 2 mg/l

T°C < 25°C

4 March 2009

Pre treatment design and evaluation for three plants

• Oman Sur (Sultanate of Oman) : Beach well

• Gold Coast (Australia) : Open intake

• Fujairah (UEA) : Open intake

1. Case of Oman Sur

BW Flow rate pumped m³/d 187 617

1. Case of Oman Sur Plant

The plant nominal capacity shall be 80 200 m³/d

33 beach wells split up into 3

areas corresponding to 3 main

underground water incomes

Piping network length of ~4000m

Wells yield 70 & 100 l/s result of :

best optimization

(OPEX/CAPEX)

limitation of equipments type

number

Water quality

parameter

New

BW-

6

BW-1 FW-1 BW-2 FW-2 BW-3 FW-3

SDI-15min (Millipore HAWP membrane)

0.8 1.3 0.5 – 0.6 0.8 0.9 0 -0.6 -

pH 7.4 7.4 7.4 7.3 7.3 7.3 7.3

TOC (mg/L) 0.67 < 0.5 0.5 0.79 0.5 < 0.5 0.81

Total Nitrogen (mg/L) 0.21 0.15 0.12 0.30 0.26 0.27 0.25

Total UV254 (/m) 0.83 0.74 0.72 0.86 0.78 0.65 0.81

Total Hydrocarbons (mg/L) < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

1. Case of Oman Sur : Raw water quality

0

5

10

15

20

25

30

35

Abu Dhabi

(March -

June 2004)

Perth (Dec

2004)

Toulon (2005

- 2007)

Ashkelon

(2005-2006)

Carboneras

(Sept 2005)

Sydney (Aug

2006 - Feb

2007)

Sur, Oman

(Jan 2006)

Sur, Oman

(April 2007)

Koweit

(March 2007)

SD

I-3

min

1. Case of Oman Sur : Comparative SDI

1. Case of Oman Sur: Beach wells implementation

Optimized general layout

1. Case of Oman Sur : Beach wells pumping

Simple Filtration mono or dual media

Anti scalingFiltration

Cartridge

Filters

HP Pumps

RO Membranes

reminéralisation

Chlorination

treated water

tank

Shock

chlorination

• No Coagulant

• No acid

• No sludge treatment

3 existing plants working on the same

site does not use chemicals for the

pre treatment

• Shock chlorination

• Chlorine injection upstream of the seawater pumps is done in

order to control sea shell growth and sea flora.

• The chlorine is injected as chlorine solution which is

prepared by means of NaOCl.

Prechlorination type Shock treatment

Dose mg/l 2

Frequency 1 h / day

NaOCl solution concentration % 12.5

Cas of Oman Sur : Chlorination of the inlet

1st stage filter criteria

Feed Filter Flow rate m³/d 61,675

Number of Filters

Horizontal pressure filters

6

Dual Media Filtration pumice media -

Sand

600 mm

600 mm

Diameter of the filter m 3.50

Surface of a filter m² 42

Filter Cycle h 48

Filter velocity m/h 10.2

Feed Filter Flow rate m³/d 125,942

Number of Filters

Horizontal pressure filters

8

Filter velocity m/h 15.6

MonoMedia Filtration Sand 600 mm

Case of Oman Sur : Filtration

II nd stage filter criteria

Case of Oman Sur : Filtration

Case of Oman Sur : view of the pre treatment

The Gold Coast Desalination plant has been constructed as a part of

the Queensland State Government’s $9 Billion South East Queensland

Water Grid Strategy. This Strategy has been developed in response to a

growing population and unprecedented drought, which has seen the

region’s water storages fall to below 20% of capacity.

The project is a Design, Build and Operate contract with a fifteen

year operations and maintenance period.

The Alliance style project includes the delivery of a 125 ML/day

Seawater Reverse Osmosis plant, and the construction of two tunnels 2.0

and 2.2 kilometers long. 24.5 kilometers of delivery pipework has also

been constructed to connect the desalination plant to the SEQ Water

Grid.

2. Case of Gold Coast Desal Plant

The pipeline runs 24.5 kilometres from Tugun to Worongary

and connects to the South East Queensland Water Grid

Units Range

Nominal

capacity

m3/day 125,000

Annual

volume

m3/year 45,656,250

Plant

availability

% 94

Operation Day/year 343

Design

capacity

m3/day 133,000

4 March 2009

Parameters (Gold Coast Desal Plant)Units Range / Max value

Seawater design temperature Deg C 17 – 28

Seawater total dissolved solids design values mg/L 34,000 – 38,000

pH 7.6 – 8.3

Total suspended solids mg/L 10

Turbidity NTU 7

Bicarbonate as HCO3 mg/L 160

Carbonate as CO3 mg/L 30

Chloride as Cl mg/L 21,000

Sulphate as SO4 mg/L 3,000

Fluoride as F mg/L 1.8

Bromides mg/L 76

Dissolved hydrocarbons mg/L 0.10

Total organic carbon mg/L 4

Calcium mg/L 450

Magnesium mg/L 1,450

Sodium mg/L 11,700

Boron mg/L 5

Red tide in Gold Coast

Map of EPA

sampling locations.

• The pre-treatment pilot plant was constructed and

installed at Kropp Park at Tugun Beach.

• The pilot plant is a granular media filtration system that

can operate in contact or direct filtration mode.

• The seawater intake is located 1.5 km offshore from

Kropp Park in 24 m of water.

• The pre-treatment pilot plant and intake was

commissioned the week of the 4 September and runs

commenced week of 12 September 2006.

2. Case of Gold Coast DP : Pilot Plant

Parameter Value

Flocculation time 20 mins

Flocculation G value 75 sec-1,

Filtration rate 6.7 m/hr

Filtration time 29 hrs/31 hrs

Ferric Sulphate Dose Rate 6 - 18 mg/L

Cationic Polymer (LT 425) 0 – 0.21 mg/L

Coagulation pH 6.7

Filter Media

Sand / Australian filter coal

0.7 mm E.S. - depth 900 mm

1.5 mm E.S. - depth 800 mm

2. Case of Gold Coast : Pilot plant design

GCDA Pilot Plant

Raw Water SDI3, Filtered Water SDI15 after 5 hours, Chemical Dose Rates

0

5

10

15

20

25

30

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

Run Number

SD

I3, F

err

ic S

ulp

hate

Do

se R

ate

(m

g/L

)

0

1

2

3

4

5

6

7

8

9

SD

I15

, C

at

Po

lym

er

Do

se R

ate

(m

g/L

)

Raw Water SDI3 Avg Ferric Sulphate Dose Rate (mg/L)

Avg Polymer Dose (mg/L) Filtered Water SDI15 after 5 hours

Fe2(SO4)3 =12-18 mg/L; pH =6.7 ; Filter Rate =6.7 m/hr; Cat Poly = 0.2 mg/L; Floc Time = 20 mins

0.0

1.0

2.0

3.0

4.0

5.0

6.0

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30

Operation Time (Hours)

SD

I

0.00

0.05

0.10

0.15

0.20

0.25

0.30

Tu

rbid

ity (

NT

U)

SDI F1 Turbidity F1

Fe2(SO4)3 =12-18 mg/L; pH =6.7 ; Filter Rate =6.7 m/hr; Cat Poly = 0.2 mg/L;

Floc Time = 20 mins, Direct Filtration

0.0

0.3

0.5

0.8

1.0

1.3

1.5

1.8

2.0

2.3

2.5

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30

Operation Time (Hours)

dP

(m

)

0.0

4.0

8.0

12.0

16.0

20.0

Ch

em

ica

l D

ose

Rate

s (

mg

/L)

DP F1 Ferric Dose Polymer Dose

Fe2(SO4)3 = 6-14 mg/L; pH =6.7 ; Filter Rate =6.7 m/hr; Cat Poly = 0 - 0.2 mg/L;

Floc Time = 20 mins, Direct Filtration

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

5.50

6.00

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

Operation Time (Hours)

SD

I15

0.0

4.0

8.0

12.0

16.0

Ch

em

ica

l D

ose

Rate

s (

mg

/L)

SDI15 Ferric Dose Cationic Polymer Dose

After 11 weeks testing the seawater SDI3 values have varied

from 11.5 to 25.2.

After the filter run is allowed to mature to filtered water SDI15

values around 3.0 through high doses of chemical coagulants,

the filter bed appears to reach a stabilisation which allows

chemical dose rates to then be decrease.

The direct filtration process at a filtration rate 6.7 m/hr has

proved effective with filter run times >40 hours. Results to

date indicate direct filtration at a filter rate of 6.7 m/hr with

a flocculation time of 20 minutes achieved suitable SDI15

values and filter run times.

Gold Coast Desalination water Treatment

coagulant

Floculant

acidantiscalant

Cartridge

filters

Dual media

filter

High

pressure

pumps

membranes

Remineralisation

Final

chlorination

Treated

water

CO2, Lime water

2. Case of Gold Coast :Flocculation tank sizing

19.9minResidence time 4 units

1,178m3Volume per unit

3uNumber of tanks in

series per unit

4uNumber of unit

345,394m3/dFilter feed water

Flocculation

19.9minResidence time 4 units

1,178m3Volume per unit

3uNumber of tanks in

series per unit

4uNumber of unit

345,394m3/dFilter feed water

Flocculation

119.3m2Filter area

Sand + Anthracite

Filter type

Dual media gravity filter

18uNumber of filter

119.3m2Filter area

Sand + Anthracite

Filter type

Dual media gravity filter

18uNumber of filter

1600mmTotal Height of media

layer

1600mmTotal Height of media

layer

6.6m/h

Filtration rate

- 18 filters (N) 6.6m/h

Filtration rate

- 18 filters (N)

2. Case of Gold Coast :Filtration design

13% (130 g/L of active

chlorine)

0 to 10 as active chlorine

Inlet of the intake pipe,pumping orDischarge pipe of the intake pumps

Concentration

Dosing rate

mg/L

Frequency

Injection point

NaOH

Liquid

1h/day

Concentration

Dosing rate

mg/L

Frequency

Injection point

NaOCl

Liquid

98%

35 maxi

Continuous

Static mixer prior

pre treatment

Concentration

Dosing rate

mg/L

Frequency

Injection point

H2SO4

Liquid

Frequency

H 2 SO 4

Liquid

40 %

4 maxi (Fe)

Continuous

Static mixer prior to pre- treatment

Concentration

Dosing rate

mg/L

Frequency

Injection point

Fe2(SO4 )3

Liquid

pre- treatment

Fe 2(SO 4 )3

Liquid

100 %

0.2 maxi

continuous

Static mixer prior to

flocculation

Concentration

Dosing rate

mg/L

Frequency

Injection point

Polyelectrolyte

Liq or Powder

100 %

0.2 maxi

continuous

flocculation

Injection point

Polyelectrolyte

Liq or Powder

TURBIDITY

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

10,0

08/12/08 18/12/08 28/12/08 07/01/09 17/01/09 27/01/09 06/02/09 16/02/09 26/02/09

NT

U

Internal Lab NATA Lab) Limit

TOTAL ORGANIC CARBON

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

10,0

08/12/08 18/12/08 28/12/08 07/01/09 17/01/09 27/01/09 06/02/09 16/02/09 26/02/09

mg

/L

NATA Lab Limit

.

2.Case of Gold Coast : SDI, TOC & Turbidity inlet water

0

5

10

15

20

25

30

35

13.12.2

008

17.12.2

008

20.12.2

008

2712

.200

8

30.12.2

008

02.01.2

009

05.01.2

009

09.01.2

009

12.01.2

009

15.01.2

009

18.01.2

009

21.01.2

009

27.01.2

009

30.01.2

009

02.02.2

009

05.02.2

009

09.02.2

009

12.02.2

009

15.02.2

009

18.02.2

009

SD

I 3 r

aw

wate

r

SDI 15 & Turbidity on the filtered water

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

13.1

2.2

008

16.1

2.2

008

18.1

2.2

008

20.1

2.2

008

22.1

2.2

008

28.1

2.2

008

30.1

2.2

008

01.0

1.2

009

03.0

1.2

009

05.0

1.2

009

07.0

1.2

009

10.0

1.2

009

12.0

1.2

009

14.0

1.2

009

16.0

1.2

009

18.0

1.2

009

20.0

1.2

009

22.0

1.2

009

27.0

1.2

009

29.0

1.2

009

31.0

1.2

009

02.0

2.2

009

04.0

2.2

009

06.0

2.2

009

09.0

2.2

009

11.0

2.2

009

13.0

2.2

009

15.0

2.2

009

17.0

2.2

009

20.0

2.2

009

SD

I 15

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

2

Tu

rbid

ity (

NT

U)

2. Case of Gold Coast : SDI & Turbidity

The sea water SDI3 has been around similar values as during

the pilot plant work from 16 to around 28.

The pre-treatment filters have been operating for 6 months and

are achieving SDI15 values of around 2.8 to 3.5 typically just

over 3.0 with filter run times in excess of 40 hours.

The initial acceptance testing at 33 and 66% have been

complete and now they are moving onto 100% testing.

2. Case of Gold Coast : six months of operation

4 March 2009

Gold Coast Desalination Plant

Gold Coast Desalination Plant

FUJAIRAHFUJAIRAH 1

- Degrémont

FUJAIRAH 2

- Veolia

Fujairah power and desalination plant (F1 and now there is F2) is a hybrid

plant at Qidfa', Fujairah in the United Arab Emirates. It is located next to the Qidfa

Power Station 5 kilometres (3.1 mi) south of Khor Fakkan and 20 kilometres

(12 mi) north of the city of Fujairah. The Fujairah plant is the first hybrid plant in

the Middle East, and the largest desalination hybrid plant in the world.

3. Case of Fujairah ( UEA)

Parameter Units

Design analysis

parameters

Temperature °C 22-33

pH 8.05

Turbidity NTU 3.33 (max)

TDS (Total Dissolved Solid) ppm 40,500

SDI (Silt Density Index) %/min 14.4 -28

Total Petroleum Hydrocarbon Content ppm < 0.1

Water flow rate base solution m3/day 365 882

Hourly flow base sol m3/h 15 245

Produced Flow m3/day 136 800

3. Case of Fujairah (UEA)

Sea water

Chlorination

Possible

acid

Coagulant

Flocculant

Flocculation

Dual media filters

Sea water

Shock

Chlorination

Acid

addition Coagulation

Flocculation

Dual media filters

Flotation

Fujairah 1 : existing Plant

Fujairah 2 : new Plant

0,0

5,0

10,0

15,0

20,0

25,0

19/4/08 0:00 9/5/08 0:00 29/5/08 0:00 18/6/08 0:00 8/7/08 0:00 28/7/08 0:00 17/8/08 0:00 6/9/08 0:00 26/9/08 0:00 16/10/08 0:00

Date and TimeNotes: TSS in mg/L

EPC

Range

value

3. Case of Fujairah - Seawater TSS monitoring

Exceptional bloom algae

“The 'red tide' happens every year but, for a number of reasons, this year it has been the worst for years. The size and spread of the occurrence has adversely affected fishing and tourism industries.”

Saif Mohammad Al Shara, Director of the East Region Office for the Ministry of Environment and Water

Gulf News, 18/11/08

SDI

0,0

5,0

10,0

15,0

20,0

25,0

30,0

35,0

19/4/08 0:00 9/5/08 0:00 29/5/08 0:00 18/6/08 0:00 8/7/08 0:00 28/7/08 0:00 17/8/08 0:00 6/9/08 0:00 26/9/08 0:00 16/10/08 0:00

Date and Time

SD

I 3

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

10,0

SD

I 15

Raw Water SDI3 Filtered Water SDI15 SDI3 Raw Water Moving Average SDI15 Filtered water Moving average

SDI during the complete two normal periods

SDI

0,0

5,0

10,0

15,0

20,0

25,0

30,0

35,0

40,0

27/8/08 0:00 1/9/08 0:00 6/9/08 0:00 11/9/08 0:00 16/9/08 0:00 21/9/08 0:00

Date and Time

SD

I 3

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

10,0

SD

I 15

Raw Water SDI3 Filtered Water SDI15 Filtered water SDI15 moving average Raw Water SDI3 moving Average

Seawater SDI3

Surface of the floatation tank

during normal operation

Surface of the same floatation

tank during a red tide event

Seawater Quality

“Red tide” aka “Harmful Algal Bloom”, caused by the phytoplankton specie Heterosigma sp. (class Raphidophyceae).

Courtesy of Elise Marquis, Research Associate at the United Nation University, Dubai. Used with permission.

Introduction SEAWATER Chemicals Performances Conclusion

Objectives:

Chemicals dosing:

H2SO4: < 25 mg/L as pure product

FeCl3 : < 7 mg/L as Fe in the first coagulation step

FeCl3 : 0 to 0.5 mg/L as Fe in the second

coagulation step

Filtered water quality:

SDI(15 min) less than 5 at all time

SDI(15 min) less than 4 more than 90% of the

time

Filtration cycle longer than 40 hours

3. Case of Fujairah : objectives of Pilot plant in conformity

Pretreatment diagram

Sea Water

Coagulation

Floatation

Dual media

filtration

NaHSO3

H2SO4

FeCl3

White water (mix of

floated water and

dissolved air)

Flocculation

Sludge

Polymer

FeCl3

Temporary

storage

Discharge back to

sea

Backwash

NaOCl

Fujairah :

Conclusion

A proper pre treatment is therefore considered to be the key to

successful RO plant operation

The choice of the pre treatment depends of the raw water quality

and its evolution during the year.

All the parameters have to be considered (red tide & bloom algae,

hydrocarbons,TOC, T°C) and not only Turbidity and SDI.

Pilot plant is recommended whenever it is possible.

The data collected by Veolia over the past 10 years allows us a

good understanding of the phenomena that occur in seawater, and

helps us offer the best solution