A,. Ultrapure water works
Laboratory ultra pure water is usually raw water pretreatment system, reverse osmosis purification system, ultra-purification treatment system consists of three parts. The main purpose is to make the pretreatment of raw water to achieve water reverse osmosis membrane separation module requirements to ensure the stable operation of the reverse osmosis purification system. Reverse osmosis membrane system is a one-time 98% of the raw water to remove ions, organic and 100% of microorganisms (in theory) the most cost-effective purification method. After the ultra-purification treatment systems through a variety of integration technologies to further remove the remaining traces of reverse osmosis water ions, organic matter and other impurities to meet the different uses of the final water quality indicator.
Second, the raw water pretreatment system
Pretreatment system usually consists of polypropylene fibers (PP) and activated carbon filter (AC) filter. On the hardness of raw water softening resin need to install filters. PP filter can efficiently remove the raw water 5μm or more mechanical particulate impurities, rust and big jelly and other pollutants, protect downstream filter, which is characterized by pollutant carrying capacity, low prices. AC activated carbon filter raw water can be efficiently adsorbed chlorine and some organics, colloids, polyamide composite reverse osmosis membrane to protect against chlorine oxidation. Raw water softening resins can be removed most of calcium and magnesium ions, to prevent clogging up the RO membrane fouling, improve water recovery.
Three, ultra-pure water reverse osmosis purification system
RO (Reverse Osmosis, referred to as RO) is a pressure difference between a high-driven membrane separation technology, with a high degree of separation, no phase change, simple and efficient characteristics. Reverse osmosis membrane "pore" has little to nanometer (1nm = 10-9m), scanning electron microscope can not see the surface of any "filter" the hole. The osmotic pressure above the operating pressure of the raw water, the water molecules through the RO reverse osmosis semipermeable membrane, water output, and a large amount of inorganic ions in the raw water, organics, colloids, microorganisms, pyrogens, etc. are retained RO membrane.
Usually when raw water conductivity <200μS/cm when an RO water conductivity ≤ 5μs/cm, meet laboratory three water standards. For areas of high raw water conductivity in order to save up mixed bed ion exchange resin replacement costs, improve water quality, customers can consider choosing two reverse osmosis purification system, two RO water conductivity of about 1 ~ 5μS/cm, and raw water quality related.
Fourth, the post-processing system ultrapure
① mixed bed ion exchange purification column
Mixed-bed ion exchange purification column with an anion exchange resin and cation exchange resin mixed proportionally. Cation exchange resins which H + exchange removal of cationic, anionic exchange resin with its OH-exchange removal of anions in the mixed bed resin was exchanged out of the H + and OH-combine to generate H2O, so mixed bed ion exchange purification columns available RO pure water to remove the remaining depth of trace ions. Small laboratory ultra-pure water in a mixed bed ion exchange purification column is usually a one-time use only. Yong Jie of mixed bed ion exchange purification column using imported nuclear grade mixed bed resin, its production water resistivity up 18.2MΩ.cm.
② EDI device
Continuous electro-deionization EDI (Electrodeionization acronym), is the use of mixed bed ion exchange resin to water ions, while the adsorption of these ions and the role of the DC voltage, respectively, through the ion exchange membrane is continuously removed process. This new technology can replace the traditional ion exchange (DI), ultra-pure water production 10MΩ.cm above. EDI's biggest advantage is the depth of demineralization long-term stable operation without regeneration with acid cation and anion resin, very suitable for making water 100L / h above the central ultrapure water preparation system, stable quality and significantly reduce operating costs, TOC will also lower and more stable. Yong Jie of EDI devices typically yield water resistivity of about 15 ~ 18MΩ.cm.
③ depyrogenation ultrafiltration
Ultrafiltration depyrogenation has been widely used in modern pharmaceutical industry. Ultrafiltration (Ultrafiltration, abbreviated "UF") membrane pore size of reverse osmosis and microfiltration range between (about 0.01 ~ 0.1μm), are usually expressed with a minimum molecular weight retention. Yong Jie of depyrogenation ultrafiltration using 5000 dalton molecular weight cutoff polysulfone membrane, which can completely remove pyrogens (usually greater than the minimum molecular weight 7000) and various types of microorganisms.
④ UV germicidal lamp UV digestion and TOC
254nm wavelength UV light using ultraviolet radiation sterilization, can effectively destroy microorganisms DNA molecule to form aggregates and two TT can not reproduce, the air, water, a safe and effective method of sterilization used. TOC UV digestion maker can be generated simultaneously 185nm/254nm dual wavelength UV lamp, which 185nm ultraviolet radiation in the air to produce ozone and sterilization in addition to taste, the water will produce hydroxyl radicals, trace organic compounds in pure water can be rapidly oxidized of CO2, to achieve the purpose of removal of TOC.
⑤ final filter
Aperture terminal 0.22um filter can completely filter out bacteria, fungi, and spores, resin fragments and all micron contaminants. Final filter in the form of hollow fiber, PP drum filters, bag filters, such as syringe filters, membrane materials are polypropylene, nylon, polyvinylidene fluoride.