1. Preparation principle of ultra-pure water from laboratory water purifier
The water purifier in Hangzhou Yongjieda Laboratory usually consists of three parts: raw water pretreatment system, reverse osmosis purification system and ultra-clean post-treatment system. The purpose of pretreatment of laboratory pure water machine is to make raw water meet the inlet requirements of reverse osmosis membrane separation module and ensure the stable operation of reverse osmosis purification system. The reverse osmosis membrane system of laboratory pure water machine is the most economical and efficient purification method to remove more than 98% ions, organics and 100% microorganisms in raw water at one time (theoretically). The ultra-clean post-treatment system of laboratory pure water machine further removes trace ions, organic substances and other impurities in reverse osmosis pure water through various integrated technologies to meet the final water quality index requirements for different purposes.
2. Raw water pretreatment system of laboratory water purifier
The pretreatment system of laboratory water purifier usually consists of polypropylene fiber (PP) filter and activated carbon (AC) filter. For raw water with high hardness, it is necessary to install a softening resin filter. PP filter element can efficiently remove mechanical particle impurities, rust, large colloid and other pollutants above 5μm in raw water, and protect the subsequent filters. It is characterized by large pollution capacity and low price. AC activated carbon filter element of laboratory water purifier can efficiently adsorb residual chlorine and some organic substances and colloids in raw water, and protect polyamide reverse osmosis composite membrane from residual chlorine oxidation. Softening resin can remove most calcium and magnesium ions from raw water, prevent scaling and blockage on the surface of RO membrane in the future, and improve the recovery rate of water.
3. Reverse osmosis purification system of laboratory water purifier
Reverse osmosis is a high-tech membrane separation technology driven by pressure difference, which has the characteristics of high once separation, no phase change, simplicity and high efficiency. The "pore size" of reverse osmosis membrane is as small as nanometer (1nm= 10-9m), and there is no "filtering" hole on the surface under scanning electron microscope. Under the operating pressure higher than the osmotic pressure of raw water, water molecules can reverse osmosis through RO semi-permeable membrane to produce pure water, while a large number of inorganic ions, organic substances, colloids, microorganisms and heat principles in raw water are intercepted by RO membrane.
Usually when the conductivity of raw water
4. Ultra-purification post-treatment system of laboratory pure water machine
① Mixed bed ion exchange purification tower
The mixed bed ion exchange purification column is composed of anion exchange resin and cation exchange resin mixed in proportion. Cation exchange resin uses its H+ exchange to remove cations in water, anion exchange resin uses its OH- exchange to remove anions in water, and H+ and OH- exchanged in mixed-bed resin combine to generate H2O, so the mixed-bed ion exchange purification column can be used to deeply remove residual trace ions in RO pure water. The mixed-bed ion-exchange purification column in ultra-pure water purifier in small laboratory is usually used once. Yongjieda mixed-bed ion exchange purification column adopts imported nuclear-grade mixed-bed resin, and the produced water resistivity can reach18.2mΩ cm.
②EDI device
Continuous electrodeionization EDI (abbreviation of electrodeionization) is a process in which anions and cations in water are adsorbed by mixed-bed ion exchange resin, and at the same time, these adsorbed ions are continuously removed through anion-cation exchange membranes under the action of DC voltage. This new technology can replace the traditional ion exchange (DI) to produce ultra-pure water above10mΩ. cm. The biggest advantage of EDI deep desalination is that it can run stably for a long time and does not need acid and alkali to regenerate anion and cation resins. It is very suitable for the central preparation system of ultrapure water with water output greater than 100L/h, and the water quality is stable, which will greatly reduce the operation cost and make TOC lower and more stable. The usual water production resistivity of Yongjieda EDI device is about 15 ~ 18mω. centimetre ..
③ Pyrogen removal ultrafiltration membrane
Ultrafiltration pyrogen removal has been widely used in modern pharmaceutical industry. The pore size of ultrafiltration membrane is between reverse osmosis and microfiltration (about 0.0 1 ~ 0. 1 micron), which is usually expressed by the minimum cut-off molecular weight. Yongjieda pyrogen removal ultrafiltration membrane adopts polysulfone membrane with molecular weight cut-off of 5000 daltons, which can completely remove pyrogen (its minimum molecular weight is usually greater than 7000) and various microorganisms in water.
④ UV germicidal lamp and TOC UV digester.
Ultraviolet germicidal lamp uses ultraviolet light with wavelength of 254nm to sterilize, which can effectively destroy DNA molecules of microorganisms and make them form TT dimer and cannot reproduce. It is a safe and effective common sterilization method for air and water. The ultraviolet digester of TOC adopts ultraviolet lamp tube, which can simultaneously produce 185nm/254nm dual wavelength. Among them, 185nm ultraviolet rays can generate ozone for sterilization and deodorization in the air, and hydroxyl radicals can be generated in water, which can rapidly oxidize trace organic substances in pure water into CO2 to achieve the purpose of removing TOC.
⑤ Terminal filter
The terminal filter with a pore size of 0.22um can completely filter out bacteria, fungi and spores, resin fragments and all micron-sized pollutants. The terminal filters are hollow fiber filter, PP bucket filter, bag filter and needle filter, and the membrane materials are polypropylene, nylon and polyvinylidene fluoride.
5. Laboratory water purifier application:
High performance liquid chromatography, TOC analysis, atomic absorption spectrometry, ion chromatography analysis, mass spectrometry analysis, determination of trace metals, preparation of identification solution, microbial analysis, tissue culture, sample dilution, glassware washing for identification, application scope of TCEP and TCEI series, DNA sequencing, PCR and electrophoresis, and antibody extraction by tube culture. General qualitative analysis, urine analysis, tissue examination, parasite examination, glassware cleaning: examination room analysis, microbial examination; Analytical water, washing water, physical and chemical analysis of automatic equipment, and high-precision instrument cleaning; Water for blood and serum examination, mass spectrometry and atomic absorption; AA, ICP cell culture, gas chromatography analysis, tissue culture medium preparation and other water; Water is used in cell culture, amino acid analysis, molecular biology experiment, PCR, gene research and cell culture in low-wavelength HPLC, TOC, IC, GC/MS and IVF.
Hangzhou Yongjieda is a professional manufacturer of laboratory water purifiers. HYJD series is a laboratory water purifier superior to the first-class laboratory water standard.