DESALINATION

WHAT IS DESALINATION?

It’s the process that removes dissolve salts from raw water or seawater, reducing the Total Disolved Solids (TDS) concentration to a minimum so it can be used for residential, commercial or industrial applications.

We can classify water by TDS concentration using the following rule:

Freshwater – Less than 1,000 ppm
Slightly saline water – From 1,000 ppm to 3,000 ppm
Moderately saline water – From 3,000 ppm to 10,000 ppm
Highly saline water – From 10,000 ppm to 35,000 ppm

Ninty seven percent (97%) of the world’s water is “saline”, to put that in perspective, according to the United States Geological Survey (USGS) there is approximately 324,088,000 cubic miles of saline water in the world, and the water consumption in 2010 was near 960 cubic miles.

“The scarcity of freshwater resources and the need for additional water supplies is already critical in many arid regions of the world and will be increasingly important in the future. Many arid areas simply do not have freshwater resources in the form of surface water such as rivers and lakes. They may have only limited underground water resources, some that are becoming more brackish as extraction of water from the aquifers continues.” USGS

HOW DO YOU DESALINATE WATER?

There are mainly two physicals phenomenons that can help us desalinate water:

Evaporation (Distillation)

Heating water causes a change of the physical state from liquid to gas and therefore a separation from dissolve solid (that precipitate)

Reverse Osmosis (RO)

It is a water treatment method that uses the physical phenomenon of osmosis to generate fresh water (product) with a low concentration of total dissolved solids (TDS).

By creating a pressure differential in a semi-permeable membrane large enough to reverse the osmosis process a liquid can be saturated with dissolved solids (rejection) and thus obtain the product water with a low TDS content.

WHY DESALINATION WITH REVERSE OSMOSIS?

The fresh water needs in the world are increasing exponentially over time, thus people needs better and better solutions that can solve this problem.

WATER QUALITY

A typical reverse osmosis membrane can filtrate up to 99% of the TDS contained in the water.

SPACE AND TIME EFICIENT

A desalination plant mainly consist of pressure vessels arrays that can be arrange in very efficient space modules and in very little time.

ENERGY EFFICIENT

The equipment used in a desalination plant are engineered to take a full advantage of the energy supply. High efficiency pumps, energy recovery devices (ERD) and solar systems makes the RO industry a go-to in water treatment.

OUR SOLUTION

Typically we recommend the following steps:

Complete flowchart for desalination below showing the ADVANCEES systems. This flowchart vary based on raw water quality and customer’s requirement. Many options and combinations are possible, the best solution needs to accommodate the minimum life cycle cost such as low operating cost, low maintenance, easy to operate and monitor.

What makes water saline?

Saline water has large levels of dissolved salts (referred to as “concentrations”). The concentration in this context is the quantity of salt in water (by weight), given in “parts per million” (ppm). If dissolved salts are present in water at a concentration of 10,000 parts per million (ppm), dissolved salts account for one percent of the water’s weight.

THE BEST DESALINATION PROCESS

Desalination removes salt and other impurities from seawater, transforming it into freshwater for drinking, irrigation, and industrial use. As population growth, urbanization, and climate change intensify global water scarcity, desalination plays a critical role in providing reliable, sustainable water supplies.

A Brief History of Desalination

While ancient civilizations used distillation to produce freshwater from seawater, the modern era of desalination began in the mid-20th century. Technological advancements and rising demand in arid regions drove the evolution of efficient, large-scale desalination systems.

Main Types of Desalination Technologies

Desalination technologies fall into two primary categories:

Thermal Desalination
Involves heating seawater to create steam, which is condensed into freshwater.
Membrane Desalination
Uses semi-permeable membranes to remove salts and impurities without heating the water.

Reverse Osmosis (RO)

The most widely used desalination method today is Reverse Osmosis. It forces seawater through a semi-permeable membrane under high pressure, removing up to 99% of dissolved salts and contaminants. RO is energy-efficient and effective for both large-scale and smaller decentralized applications.

Multi-Stage Flash (MSF) Distillation

This thermal method involves flashing seawater into steam at low pressure, then condensing it into freshwater. MSF is reliable and used in large installations but is energy-intensive.

Multi-Effect Distillation (MED)

MED systems use multiple evaporation-condensation stages, reusing heat between stages to improve efficiency compared to MSF.

Electrodialysis (ED)

ED uses electric fields and ion-selective membranes to separate salts from water. It’s less energy-intensive than thermal methods but typically less efficient in salt removal.

Capacitive Deionization (CDI)

An emerging technology, CDI uses electrodes to adsorb salt ions from water. Though still in development, it shows promise for reducing energy consumption.

Hybrid Desalination Systems

Hybrid systems combine technologies (e.g., RO + thermal, ED + CDI) to optimize water recovery, energy use, and operational costs. These systems maximize strengths and reduce limitations of individual methods.

Challenges and Environmental Considerations

Energy Consumption: Desalination is energy-intensive, often relying on fossil fuels.
Brine Disposal: The by-product of desalination can harm marine ecosystems if not properly managed.
Cost: While prices are falling, desalination remains more expensive than conventional water sources.

Future of Desalination

Innovations such as solar-powered systems, forward osmosis, and nanotechnology are improving efficiency and environmental performance. As water scarcity becomes more pressing, desalination will be an increasingly essential solution globally.

Countries like Saudi Arabia, the UAE, Israel, and Australia already rely heavily on desalination. In the U.S., especially in coastal states, adoption is growing rapidly.