Water treatment for district heating and energy sectors
Continuous technological development in industry and the introduction of new solutions aimed at increasing process plant efficiency and efficiency results in more stringent quality criteria for water used in production processes. Environmental protection regulations and diminishing water resources, which could be a source of water supply for industrial plants, intensify the search for solutions for their improvement.
State-of-the-art techniques of water treatment
The energy sector and many other industries require water with very high quality parameters. Production of such water is possible thanks to the process of electrodeionization (EDI). Electrodeionization is a combination of two water treatment methods: electrodialysis (ED) and ion exchange demineralization (DI).
Water treated in an EDI system passes through one or more chambers filled with ion exchange resins located between the cationic and anionic selective membranes. The ion exchange beds in electrodeionization (EDI) systems are regenerated on a continuous basis, so they are not deplete as much as in the case of ion exchange resin beds used in ion exchange columns.
Typically, reverse osmosis is used prior to the EDI process to remove the main ion charge. Practically RO removes approx. 95% ions; EDI, on the other hand, removes about 95% of the remaining ions, as well as carbon dioxide and silica. Water produced by EDI systems usually has conductance below 1 µS/cm. If it is necessary to obtain water of even higher quality, after the EDI process water passes through a column filled with a mixed bed: highly acidic cation exchanger – highly alkaline anion exchanger.
Typical processes used in these facilities
- Mechanical filtration (reducing mechanical impurities, protection of equipment and water systems)
- Water softening (reducing water hardness, protecting and extending the life of individual equipment items)
- Reverse osmosis (RO) (production of low conductivity water)
- Electrodionization (EDI) (production of ultrapure water)