How Does Salt Water Purification System Work ?
Water has wide range of minerals and compounds inside. 95% of water in the world can not be used directly. It needs treatment. Biggest challenge is salt. When we hear the word of salt, we know that it is Sodium Chloride (NaCl), it is also known as table salt. As chemistry, salt is a chemical compound consisting of an ionic assembly of a positively charged cation and a negatively charged anion, which results in a compound with no net electric charge.
Salts can be classified in a variety of ways. Salts that produce hydroxide ions when dissolved in water are called alkali salts. Salts that produce acidic solutions are acid salts. Neutral salts are those salts that are neither acidic nor basic. Zwitterions contain an anionic and a cationic centre in the same molecule, but are not considered to be salts. Examples of zwitterions include amino acids, many metabolites, peptides, and proteins.
In fact that we know the taste of salt from table salt, if water has excess of NaCl, it can not be drinkable or you can not use in your industrial process. So how to remove salt from water ?
In industry, there are two main process:
1. Water Evaporation with Heating Process
2. Water desalination with Reverse Osmosis (RO) membrane
Our company is specialized on water treatment systems with RO membrane technology, so we will explain here, how ro water treatment system make salt water purification.
If water TDS (total dissolved solid) is less than 1000ppm, we call this water as fresh water, as regards to World Health Organization, potable water TDS must be less than 600ppm. If water TDS is higher than 1000ppm, we called water as below table:
TDS in ppm | Water Quality |
0-1000 | Fresh Water |
1000-10.000 | Brackish Water |
10.000-100.000 | Salty Water* |
>100.000 | Brine |
*Sea water TDS 20.000-45.000ppm, depends on region.
If you want to get more info about TDS, please watch our detailed video about it.
Salt water purification need reverse osmosis membrane technology, it is pressure driven process. We send salt water to membrane, apply high pressure and do not allow salt anion and cation pass membrane small pores. RO membrane pores size is 0.0001µm, and it is more smaller than salt minerals but bigger than water molecules.
Now, we explain this process on our sea water salt water purification system. Below you see the flow diagram of seawater desalination system.
You can get water directly from sea or well, but it is better to stock in a raw water tank. As regards to your capacity, it can be pool or tank. Then water goes to multimedia filter, it is sand filter tank, remove bigger particles, if water has odor, taste and excess of chloride, we are using activated carbon filter tank, and if necessary, before or after pretreatment we add chemical dossing system (for pH, antiscalant, antifouling, chlorination, dechlorination…etc). Pretreatment tanks sand and carbon filter has backwash futures, manual or automatically, you can wash your media and use effectively.
After filter tanks, water goes to cartridge filter housing or bag filter housing, we are using generally. 1µm or 5µm PP cartridge filter or bag, this filter is called as security filter also, because it is responsible not to pass any bigger particle to membrane surface. After cartridge filter housing, salt water purification process continue with high pressure pump, it makes high pressure for membrane filtration at salt water filtration system. How does ro membrane work ? Please watch our detailed video for it.
Salt water filtration need high pressure, fresh water applications are 10bar, at salt water purification as regards to salt content pressure can go 60bar, 80bar or more, therefore we have to see your water analysis report. After RO membrane filtration, if it is necessary, we can add post treatment like water polishing, chemical dossing, uv sterilization, ozone disinfection…etc. Now, your water rid of salt, bacteria, viruses.
We call pure water after salt water purification as permeate, permeate water TDS as regards to design and your raw water quality, it can be less than 300ppm, if you need more pure water, we can use Double Pass Reverse Osmosis System.
If you want to get information about salt water filtration system, please visit our products from below links:
Our Salt Water Filtration Systems:
1. Commercial Sea Water Filtration System
2. Commercial Salt Water Filtration System
3. Industrial Seawater Filtration System
4. Industrial Brackish Water Filtration System