Drinking water from sea water sources

Our Sea Water Solutions

Turning sea water (salt water) or salt containing fresh water (brackish water) into fresh drinking water is desirable only when there are no other sources available. Membrane separation (RO) or thermal distillation are possible but costly and complex.

The Technology

A short summary about the technology behind our sea water solutions.

Step 1: Extraction of water

The type of water extraction is particularly important. Our preferred method, which guarantees sterilization, is to extract downstream, pre-filter the sea water by running it through rocks and with an appropriate well depth of >50 meters.

Step 2: Primary Pre-treatment

There are basically only two methods that can be used in this step: using gravel filters or an ultrafiltration (UF). Since surface water contains many microorganisms, water sterilization is needed. Most manufacturers use UF, which necessitates use of chemical additives and more elaborate technology.

Step 3: Secondary Pre-treatment

This step requires usage of candle filters < 5µ as well as, antiscalants to soften the water.

Step 4: Reverse Osmosis (RO)

Feed water is forced through a RO membrane with remaining salt particles removed. Apart from the membrane durability, other factors, such as the energy consumption and feedwater characteristics impact system quality and performance.

Step 5: Post-treatment

Considering that feedwater was treated with antiscalants, an adjustment of permeate pH levels, as well as, remineralization or addition of depleted minerals (filtered out together with salt particles) is required.

Comparing options for sea water treatment

Ultrafiltration vs. Gravel Filter

Ultrafiltration

Excellent Retention
Minimal space requirement
Complex technology
Chemically enhanced backwash
High maintenance requirement

Gravel Filter

Few components
Robust technology
Easy to operate (backwashing)
Large space requirement
Retention up to 80 µm only

Large scale Reverse-Osmosis (RO) solutions