The water is the predominant physical component of the surface of our planet, and it is an essential constituent of all animal and plant kingdom. Although theoretically unlimited in form and quality of sea water, this resource is actually very scarce and therefore precious.
For long time man had to strive to satisfy its need for water resources and to combat the drought affecting increasingly large areas of the Earth. Today he drastically faces pollution caused by industrialization, having postponed to the future – for too long – the emergency about the safeguard and renewability of the world’s resources, firstly its water and energy sources.
In most cases water is available only in limited quantities and with characteristics not always adapted to the civil, agricultural, commercial and industrial use. On the one hand, therefore, it is necessary to rationalize and reduce consumptions, on the other hand it is essential to increase the availability of water using technologies and techniques that allow the exploitation of alternative water resources, as well as marine and brackish water. Finally, it is also important to preserve the quality of those resources, ensuring that the wastewaters re-entered in the ecosystem are properly purified.
All our facilities operate under lean manufacturing and continuous improvement principles to increase efficiencies and reduce costs while maintaining the highest level of quality. Lean methods include improving workplace organization, reducing set-up times, streamlining process flows, continuous employee training, and more. Through lean, we’ve streamlined processes to ensure our clients receive the best prices, products and services in the industry. The water treatment with the reverse osmosis technology represents an universal solution adaptable in all situations in which it is necessary to improve the quality of available water on site to make it suitable to the expected uses.
Selmar Technologies has embraced this technology since the early 80s: the continuous effort in research and development, design and production of equipment RO (Reverse Osmosis) constitute an experience of great value, an absolute guarantee of competence and professionalism in a sector in which the ability to analyze – with maximum precision – the specific requirements is the key to success for achieving the best results in terms of efficiency, quality and energy saving.
The reverse osmosis is a natural principle, according to which if two solutions with different salt concentrations are shared by a semi permeable membrane, water passes from the less concentrated solution to the most concentrated one.
If an external pressure is applied to the more concentrated solution, the process become reversed and it causes the reverse osmosis phenomenon (water passes from the more concentrated solution to the less concentrated one).
The reverse osmosis process is the most efficient, steadiest and modern way to process seawater and brackish water. Exploiting this phisycal-chemical natural process, it is possible to obtain fresh and drinkable water with low power consumption.
This process eliminates 100% of all polluting substances and over 80% of the organic ones: the result is a water of absolute purity, with a low dry residue and a total absence of limescale and heavy metals, phosphates, nitrates and nitrites, without traces of pesticides and radioactive materials, disinfected by bacteria and viruses. A mineral water, with the right concentration of mineral salts, useful to the human body.
The reverse osmosis technology, thanks to its scalability, it proves to be efficient and convenient both when applied to satisfy relatively small and discontinuous needs, in the range of 500-1000 liters per day typical of the yachting world, and for the continuous cycle treatment of quantities sufficient to ensure the needs of entire communities, cruise ships, of entire industries: hundreds of cubic meters per day.
The application of this process is modular: from the smallest single membrane desalinators to treatment systems consisting of thousands of elements (in series or parallel), efficiency is growing, thanks to the continuous development of new materials and more sophisticated membranes.
The reverse osmosis desalinators are universally used in the marine and shipbuilding industry to obain fresh water from the seawater, and they are widely used for civil and residential use, for industrial and agricultural field, to purify sea water, brackish water or otherwise raw waters not directly usable for their characteristics.
Regardless of the size and capacity of the system, a RO desalinators (Reverse Osmosis) performs its function through three basic stages:
The incoming pre-filtering eliminates all suspended particles in the seawater and reduces its turbidity, by a passage through the filters which hold them physically. Generally plastic filters are used, you can use quartzite filters when you have to process a very turbid water.
This preventive process, providing a first improvement of water quality, also has the important function to prevent that the suspended particles, flowing directly to the reverse osmosis unit, can compromise quickly its efficiency and effectiveness.
When necessary or desirable, it may be added to a section of chemical pre-treatment.
The HP pump (High Pressure) imparts to the water the proper pressure required to entry in the reverse osmosis unit. This pump (or group of pumps in medium-large size systems) has features and benefits depending on the type of water to treat (sea water or brackish water) and the required production capacity.
The reverse osmosis unit separates the salts still present in the water, generating a certain percentage of fresh water – the permeate – and discharging the remaining concentrate. The ratio between permeate and concentrate provides a measure of the efficiency of the entire process, which increases with the increase of the size of the plant. The RO unit can be composed of one or a few membranes in a single vessel (the container that houses them) in small household desalinators or for boating, up to thousands of vessel in onshore plants which guarantee drinking water to entire communities.
The fresh water obtained can be further treated, if necessary, with a UV sterilization, that definitively breaks down the bacterial and pathogenic load; with a post-filtration active carbon, to improve the organoleptic characteristics; with a chemical post-treatment (chlorination, for example), for greater safety of preservation in the storage tanks.
The entire process is managed by an electronic control and by an instrumentation of manual or automatic command and control, depending on the complexity of the machine or plant.
Any desalinator needs a complementary flushing system (manual or automatic), useful to conduct periodic washes with fresh water, and to ensure efficiency and durability of the machine and its components.
The choice of a desalinator in standard configuration or the design and production of a specific installation are always subordinated to the capacity of which you need, the characteristics of raw water to treat and the quality of fresh water you want to obtain.