Currently, there are basically three processes for preparing ultra-pure water for the chemical industry, and most of the other process flows are derived from different combinations and arrangements based on these three basic process flows.
Advantages and Disadvantages of the 3 Process Flows
- Ion Exchange Resin: It has the advantage of requiring less initial investment and taking up less space. However, the disadvantage is that it needs to be regenerated frequently using a large amount of acid and alkali, which can be environmentally damaging.
- Two-Stage Reverse Osmosis Device: Its characteristic is that the initial investment is higher than that of the ion exchange resin method, but no resin regeneration is required. The disadvantage is that the membrane components need to be cleaned or replaced regularly, and the water quality is relatively not too high, mostly only achieving around 1us/cm. Therefore, when higher water quality is required, single-stage reverse osmosis is often used, followed by a mixed bed (anion-cation mixed bed).
- Reverse Osmosis as a Pre-treatment, followed by an Electro-deionization (EDI) Device: This is currently the most economical and environmentally friendly ultra-pure water preparation process. It can continuously produce ultra-pure water without the need for acid and alkali regeneration, which is not environmentally damaging. Its disadvantage is that the initial investment is relatively expensive compared to the above two methods.
Features of Ultra-Pure Water Equipment for Cosmetics
The traditional process for producing ultra-pure water usually involves the use of ion exchange resins, which often require regular resin regeneration, consuming both materials and labor. NEWater, after years of practice and innovation in membrane separation technology, often uses a combination of reverse osmosis and ion exchange systems (or EDI) to produce ultra-pure water. Compared with traditional processes, this process has the advantages of lower operating costs (greatly extending the regeneration cycle of ion exchangers) and reliable operation. It also has the advantages of lower cost and easy availability of consumables compared to traditional processes. The reverse osmosis process technology is advanced and reliable.
Analysis of NEWater EDI Ultra-Pure Water Equipment Technology for Cosmetics
Water requirements for cosmetics production: Water is an important component of cosmetics. The quality standard of water used in cosmetics directly affects the safety, reliability, and product quality of cosmetics. NEWater can provide 0.5-50T/H cosmetics water equipment.
The Requirements for Water Used in Cosmetics Include the Following Two Aspects:
1. Inorganic ion concentration: The ultra-pure water equipment used for cosmetics needs to remove inorganic ions from the water to meet the requirements of pure water, reducing the salt content to below 1 mg/L, that is, the conductivity needs to be reduced to 1~5μS/cm2.
2. Microbial contamination: The hygiene standards for cosmetics specify that the total bacterial count in general cosmetics should not exceed 1000/mL/g, while the total bacterial count for cosmetics used on the eyes, lips, oral mucosa, infants, and children should not exceed 500/mL/g. Moreover, fecal coliforms, Pseudomonas aeruginosa, and Staphylococcus aureus should not be detected.
3. Removal of ions in water: Ion exchange resin is usually used to remove cations from water and release hydrogen ions, while anion exchange resin is used to remove anions from water and release hydroxyl ions that combine with the hydrogen ions to form water, thereby removing the ions. However, ion exchange alone cannot thoroughly remove all ions from the water. A mixed ion exchange resin is usually added after ion exchange to remove the remaining ions to meet the water requirements for cosmetics. The resin needs to be regenerated after it is saturated with ions.
Reverse osmosis (RO) is a process where a solvent (usually water) in a solution is forced to flow from the solution side to the solvent side through a semipermeable membrane under sufficient pressure to separate the solvent. RO technology has the following advantages: high-efficiency, low-noise high-pressure pumps reduce operating noise and energy consumption.
The RO pure water system adopts different processes based on the different water qualities of the source water. Generally, after the tap water is processed by a primary RO system, the conductivity of the produced water is <10μS/cm, and after a secondary RO system, the conductivity of the produced water is <5μS/cm or even lower. After a single-stage RO system, mixed ion exchange equipment or EDI equipment can be added to produce deionized water that meets the requirements for cosmetics.
EDI technology can replace the precision desalination system after mixed bed and RO. EDI can replace the traditional mixed ion exchange technology (MB-DI) to produce stable deionized water.
Advantages of EDI Technology
Compared with mixed bed ion exchange technology, EDI technology has the following advantages:
- Stable water quality.
- Easy to achieve full automation control.
- Will not stop due to regeneration.
- No need for chemical regeneration.
- Low operating cost.
- Small plant area.
- No wastewater discharge.
Sterilization and Disinfection of Water for Cosmetics Production
1. Chemical Treatment: Sterilize by emptying salt water.
2. Heat Treatment: Heat sterilization in the reaction vessel, using ultra-high temperature short-term sterilization (abbreviated as UHST).
3. UV Disinfection: The mechanism of UV sterilization is that UV radiation acts on bacterial membrane DNA and RNA.
4. Microfiltration: Sterilize using a 0.22μm microfiltration membrane, usually combined with method three.