seawater reverse osmosis desalination

Seawater desalination

THE MOST COST-EFFECTIVE TECHNOLOGY TO OBTAIN FRESH WATER FROM HIGH-SALINITY WATER SUPPLIES

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The RO-SW series from Watercore are an ideal source of fresh water to irrigation, commercial or industrial applications when the main water intake is close to shore and have a higher than acceptable salinity.

1. Seawater desalination

The RO-SW series from Watercore are reverse osmosis systems designed to process and provide drinking-quality water from high-salinity water or seawater. These water treatment units are typically designed for high salinities (35000 mg/l TDS) and operating recovery rates between 30% and 40%.

These reverse osmosis plants are an ideal source of fresh water to irrigation, commercial or industrial applications when the main water intake is close to shore and have a higher than acceptable salinity.

Based on the source water salinity they process, desalination plants can be divided into three main groups: nanofiltration (softening) plants, brackish water desalination plants, and seawater desalination plants.

Reverse Osmosis desalination applied to seawater is the most cost-effective system capable of converting seawater into drinking water in one single pass.

Considering that Australia’s surrounding Oceans have an average salinity of 31 g/l, reverse osmosis desalination plants are remarkably cheaper to build and maintain than the old heat distillation processes.

Typical salinity levels for water found in oceans, lakes and rivers are:

500 mg/L is considered the top salinity limit for potable (fresh) water.
Rainwater has a typical salinity of 20 mg/L
Seawater has an average TDS concentration of 35,000 mg/L, with an actual range from 33,000 to 36,000 mg/L at various locations and depths.
Groundwater (lakes, rivers and underground) presents a high TDS variability. Being a consequence of the terrain’s nature and structure typical TDS values range from 200 mg/L to 15,000 mg/L.

Watercore offers energy recovery devices (ERD) as an option in all seawater desalination plants. These energy recovery systems take advantage of the elevated reverse osmosis high-pressure required in seawater environments, as a consequence of the high osmotic pressure, and helps reducing the operational costs.

Since energy used for seawater desalination contributes 50 to 70 percent of the total plant annual operation and maintenance costs, reuse of this energy is beneficial and cost effective.

All Watercore single-stage SWRO systems are designed to produce drinking water in one step using only a single set of RO trains operating in parallel. These single-stage RO desalination systems offer a consistent production of drinking water with TDS concentration lower than 200 mg/L, Chloride level of less than 100 mg/L, and Boron concentration lower than 0.5 mg/L.

2. Our range of SEAWATER reverse osmosis DESALINATION Plants

Standard Technical Data *(1)	SW-RO-15	SW-RO-20	SW-RO-25	SWO-35	SW-RO-50	SW-RO-120	SW-RO-250	SW-RO-500
Permeate flow (m3/d)	15	20	25	35	50	120	250	500
Feed TDS	< 35,000 ppm
Feed pressure	2 bar (min) – 4 bar (max)
Permeate TDS	< 200 ppm (screen-selected by user for irrigation units)
Recovery	30% – 45%
Rejection	97% – 99%
Recirculation flow	Yes
Membrane Type	Low Energy – 4″					Low Energy – 8″
Array	1/1/1	1/1/1/1	1/1/1/1/1	2/2/2/2	2/2/2/2/2	1/1	1/1	2/2
Hydraulic connections Feed Permeate Concentrate	1″ 3/4″ 3/4″	1″ 3/4″ 3/4″	1″ 3/4″ 3/4″	1″ 1″ 3/4″	1″ 1″ 3/4″	1 1/2″ 1 1/2″ 1″	2″ 2″ 1″	3″ 3″ 2″
Dimensions Width Depth Height	1400 mm 650 mm 1800mm			2400 mm 650 mm 1800mm		1400 mm 1000 mm 1800mm
Power (KW)	2,2					7,5	15	30
Power supply	50Hz, 230V (1-Phase) or 400V (3-Phases)					50Hz, 400V (3-Phases)

3. Standard and optional features in our SEAWATER reverse osmosis DESALINATION systems

Features & Options	Standard	Option
25μm cartridge filtration	Standard
High pressure pump	Standard
Low pressure pump		Optional
Stainless Steel 316 piping	Standard
Auto-flushing	Standard
Antiscalant dosing system	Standard
Chlorine Sterlization (pretreatment)		Optional
Iron, Aluminium, Manganese removal (pretreatment)		Optional
Turbidity removal (pretreatment)		Optional
Skid mounted	Standard
Containerised		Optional
VFD for high pressure pump		Optional
Energy-Saving Polyamide Membranes	Standard
Energy Recovery System (ERD)		Optional
Enhanced Boron removal	Standard

Download our brackish-water RO systems specifications

4. Feed water requirementes FOR SEAWATER reverse osmosis

Qualified Feed Water Quality*(2)
Total dissolved solids (TDS)	< 6000 ppm
PH value	2-11
Iron	< 0.05 ppm
Aluminium	< 0.05 ppm
Manganese	< 0.05 ppm
Free Chlorine	0 ppm
Oil and grease	0 ppm
Turbidity	< 1 NTU
(TOC) Total Organic Carbon	< 2 ppm
*(2) higher values of any of these parameters will require a pre-treatment. Contact us for a personalised solutions