Desalination

Reverse osmosis represents the most convenient and the safest technique for desalinization of different kinds of water. This treatment is replacing other technologies for water desalinization, thanks to the excellent combination between quality results and low operating costs. Reverse osmosis also guarantees low energy consumption and reasonable expenditure of chemical products. Furthermore, the waste water parameters fall within the sewage limits, therefore resizing more and more the problem of disposal of eluates (for example for softeners and ion exchange resin demineralization units).

Reverse Osmosis is the process used when a saline solution comes into contact with a membrane permeable to water (and not to dissolved salts) at a pressure exceeding the osmotic pressure of the solution itself.The passage from water, poor in salts (permeate), occurs through the membrane, whereas on the outside of the membrane a waste water rich in salts (brine) is obtained.

The Reverse Osmosis is a process of physical type, which does not require the use of regenerating chemicals. Reverse Osmosis technology offers total guarantee thanks to its versatility characteristics, performance excellence and ease of use. Over the years have multiplied the types of membranes available, up to the latest low energy, and their quality and reliability is well established also for those specifically designed for targeted applications.

Here below is a list of the main parameters used in the planning stage of Reverse Osmosis and desalinization processes:

• Salinity of the water to be treated;
• Temperature of the water to be treated;
• Recovery factor;
• pH;
• SDI;
• Hardness;
• Alkalinity.

The comprehension of the water characteristics must be added to these essential factors in particular, in order to improve a possible pre-treatment, it is fundamental to verify the presence of:

• Suspended solids;
• Polluting metals, such as iron and manganese;
• Bacterial concentration;
• Chlorine or oxidizing agents in general (except oxygen);
• Organic substances, sulphides, oils.

Before the Reverse Osmosis section, it is important to determine the most suitable "pre-treatment" based on the characteristics of the water to be treated in order to guarantee the greater operating continuity of the system and reduce washing frequency. A correct pre-treatment prevents relatively rapid lodgement of the membrane due to grime and/or physical impurities, lodgement due to precipitation of encrusting salts and/or metals, bacterial proliferation, contact with oxidising agents.

STA’s containerized units are available in a variety of configurations to cover flow requirements from 0,5 to 50 m3/h, with salinity levels up to 38000 ppm of TDS. The STA Reverse Osmosis systems are supplied in container units (sized 20’ and 40’) already assembled and electrically and hydraulically tested and ready to use.

Where is require high quality water, chemical and bacteriological, with the advantage, compared to the demineralization, not to have problems related to the discharges of regeneration and handling of chemical products:

• Production of pure and ultrapure water for power station;
• Desalination and production of drinking water from sea waters;
• Refining and softening of water;
• Irrigation use;
• Textile industry;
• Steel industry;
• To remove arsenic, nitrates and other pollutants.

STA’s containerized units are available in a variety of configurations to cover flow requirements from 1 to 50 m3/h, with salinity levels up to 3000 ppm of TDS. (flow rates above 50 m3/h available on request) The STA Reverse Osmosis systems are supplied in container units (sized 20’ and 40’) already assembled and electrically and hydraulically tested and ready to use.

Where is require high quality water, chemical and bacteriological, with the advantage, compared to the demineralization, not to have problems related to the discharges of regeneration and handling of chemical products:

• Desalination-production of drinking water from brackish waters;
• Production of pure and ultrapure water;
• Refining and softening of water;
• Irrigation use;
• Food industry;
• Cosmetics and pharmaceutical industry;
• Textile industry;
• Steel industry;
• In water reuse applications, and wherever you need specific water;
• To remove arsenic, nitrates and other pollutants.