Water Treatment Chemicals for Seawater Desalination: Challenges and Solutions

With the increasing global water shortage, seawater desalination has become an important way to solve the problem of water resources. Seawater has high salinity, high hardness, and complex composition, which puts forward high requirements for water treatment chemicals used in desalination processes. Water treatment chemicals are widely used in seawater desalination technologies such as reverse osmosis (RO), multi-effect distillation (MED), and electrodialysis (ED), playing a key role in preventing scaling, corrosion, and fouling. This article analyzes the challenges of water treatment chemicals in seawater desalination and proposes corresponding solutions.

The main challenges of water treatment chemicals in seawater desalination include high salinity tolerance, high temperature stability, and environmental friendliness. Seawater has a high concentration of scale-forming ions (such as calcium, magnesium, and sulfate), which are prone to form scale on the surface of desalination equipment and membranes, reducing treatment efficiency. Therefore, scale inhibitors used in seawater desalination need to have h3 chelating ability and high temperature stability to inhibit scale formation under high salinity and high temperature conditions. Corrosion is another major problem in seawater desalination, as seawater is highly corrosive to metal equipment. Corrosion inhibitors used in seawater desalination need to form a dense protective film on the metal surface, resisting the corrosion of seawater.

To solve these challenges, new types of water treatment chemicals have been developed. For example, high-efficiency phosphorus-free scale inhibitors with high salinity tolerance, such as polyepoxysuccinic acid (PESA) and polyaspartic acid (PASP), can effectively inhibit scale formation in seawater desalination systems. Composite corrosion inhibitors combining organic phosphonates and imidazolines have good corrosion inhibition effect in high-salinity seawater. In addition, green and biodegradable chemicals are gradually replacing traditional chemicals to reduce environmental impact. The combination of water treatment chemicals with advanced desalination technologies and intelligent monitoring systems can further improve the efficiency of seawater desalination, reduce costs, and promote the large-scale application of seawater desalination.